Akademik

Spinoza: metaphysics and knowledge
Spinoza: metaphysics and knowledge G.H.R.Parkinson The philosophical writings of Spinoza are notoriously obscure, and they have been interpreted in many ways. Some interpreters see Spinoza as (in the words of a contemporary)1 ‘the reformer of the new [sc. Cartesian] philosophy’. That is, they see him as someone who has been deeply influenced by Cartesianism, but who has introduced major changes in it, without rejecting it altogether (as, say, philosophers such as Hobbes and Gassendi did). Others, however, see Spinoza’s philosophy as deeply imbued with medieval thought, both Jewish and Christian. In the words of one prominent exponent of this view,2 ‘his mind is crammed with traditional philosophic lore and his thought turns along the beaten logical paths of mediaeval reasoning’. Such a way of thinking would be alien to that of Descartes, who (like many seventeenth-century philosophers) spurned the philosophy of the Middle Ages. There are other disagreements between Spinoza’s interpreters. For example, some see his philosophical writings as a way of expressing a kind of mystical insight, but others deny this.3 In trying to decide between these interpretations, it will be helpful to begin by giving some account of the social and intellectual milieu within which Spinoza formed his ideas. Spinoza was born in Amsterdam on 24 November 1632. His father, Michael de Spinoza, was a Jewish merchant, one of many Portuguese Jews who had taken refuge in the Netherlands to escape religious persecution. The family language would have been Portuguese, and the philosopher who later called himself by the Latin name ‘Benedictus’ was generally known in his youth by the Portuguese name ‘Bento’. (It is worth adding that the Hebrew name ‘Baruch’, which is still sometimes used to refer to Spinoza, was for ritual purposes only.) The Portuguese Jews of Amsterdam had founded in 1616 a school, the ‘Talmud Torah’ (‘The Study of the Law’), and the young Spinoza would have attended this school. Here, there were in effect two divisions, a junior and a senior. Instruction in the junior division continued until a boy’s thirteenth year;4 it was confined to the Bible and the elements of the Talmud, more advanced study being reserved for the senior division. The registers of this senior division have been preserved, and it is notable that, among the entries for the relevant years, the name of Spinoza is not to be found. It would be wrong, then, to suppose that Spinoza was deeply read in Talmudic lore in his youth, and that he was intended to be a rabbi. Rather, it seems to have been Michael de Spinoza’s intention that Spinoza should concentrate on a career in business; and indeed, when Michael died in 1654 Bento and his brother Gabriel carried on the family business for a time. The mature Spinoza displays far more knowledge of Jewish thought and history than could have been acquired by a twelve-year old, however precocious; and in fact when Spinoza left school he continued his Jewish studies as a member of a ‘Yeshivah’, a kind of study-circle, led by the famous rabbi Saul Levi Morteira. Spinoza, however, proved to be a rebellious pupil, and on 27 July 1656 he was formally excommunicated on account of what were called his ‘wrong opinions’ and ‘horrible heresies’.5 The exact nature of these heresies is not certain. It can be said with certainty that they were not the philosophical views for which Spinoza later became famous; it is very improbable that they were even Cartesian views, which at that time were being keenly discussed in the Netherlands—so keenly, indeed, that in 1656 Dutch university professors were required to take an oath that they would not propound Cartesian doctrines that were found offensive.6 The slender evidence that is available suggests that Spinoza was already taking up a critical attitude towards the Bible, that he disbelieved in the immortality of the soul, and that his views about God were deistic in character. These doctrines suggest, not so much the ideas of Descartes, as those of the French ‘libertins’ or free-thinkers of the period.7 There is much that is obscure about the next five years of Spinoza’s life, but it is certain that they were a decisive period in his philosophical development. By the time that his surviving correspondence begins (26 August 1661) Spinoza appears as a man who has a philosophy of his own, which is treated with respect by such men as Henry Oldenburg, who was to become the first secretary of the Royal Society in London. At this stage, Spinoza was already critical of Cartesianism, but this is not to say that he owed nothing to Descartes. Rather (as a friend of his remarked) ‘The philosophical writings of the great and famous René Descartes were of great service to him.’8 What is not certain is just when and in what way Spinoza obtained his knowledge of Descartes’s philosophy. There is reason to believe that Spinoza may have attended philosophy lectures, on an informal basis, at the University of Leiden at some time between 1656 and 1659; if he did so—and the evidence is inconclusive9—he would almost certainly have studied Descartes there. It is also possible that it was a common interest in Descartes which led Spinoza to associate with members of some of the smaller Christian sects of the period, the Collegiants and the Mennonites. The Collegiants were a group of people who tried to dispense with clergy, and who met together in groups, collegia, for the purpose of worship. The Mennonites were followers of the Dutch Anabaptist Menno Simons (1496–1561); holding themselves aloof from politics, they did not suffer the persecution that many Anabaptists did. It was in about 1661—that is, five years after his excommunication —that Spinoza wrote his first philosophical works. These were the Tractatus de Intellectus Emendatione (Treatise on the Correction of the Intellect) and the Korte Verhandeling van God, de Mensch en deszelfs Welstand (Short Treatise on God, Man and his Well-being). The firstnamed of these was a treatise on method, which was meant to be the first part of a two-part work, the second part of which was to have dealt with metaphysics.10 Spinoza did not complete the work, which was first published in 1677 as part of his posthumous works. The Short Treatise may be a first draft of the work on metaphysics which was to have followed. Confused and obscure, it was clearly not intended for publication in the form in which it stands.11 In both these works Spinoza’s distinctive philosophy is already present, though in a form that is still immature. The works are also interesting in that they afford a clear view of some of the influences on Spinoza. The Short Treatise is particularly instructive in this respect. Not surprisingly, Spinoza makes use of Descartes; for example, arguments for the existence of God contained in the eleventh chapter of Part I of the work are clearly derived from Descartes’s Meditations, Numbers 3 and 5. Equally interesting are the Dutch sources—more specifically, the Leiden sources—that Spinoza uses. In his account of God as cause12 he uses a classification of causes introduced by Franco Burgersdijck (d. 1636), who had been a professor of philosophy at Leiden; his Institutionum Logicarum Libri Duo (Leiden, 1626) and his Synopsis Burgersdiciana (published posthumously at Leiden in 1645), a manual of scholastic logic, were popular textbooks. It is not certain, however, that Spinoza read Burgersdijck’s works; he may have known them only through the works of Burgersdijck’s successor at Leiden, Adrian Heereboord (d. 1651). Heereboord produced a revised version of the Synopsis, entitled Hermeneia Logica (Leiden, 1650), which includes an exposition of Burgersdijck’s classification of causes; he also commented on this doctrine in his Meletemata Philosophica (Leiden,1654), a work actually quoted by Spinoza.13 Spinoza could also have found in the Meletemata the antithesis between natura naturans and natura naturata, used in the Short Treatise, and later in the Ethics.14 Heereboord is of particular interest in that he sympathized both with Descartes and with the scholastics, and in particular with Suarez. One should not assume, therefore, that whenever Spinoza uses scholastic terms this indicates a study of the original texts; he may well be using the scholastic Cartesian Heereboord.15 Spinoza wrote the Tractatus de Intellectus Emendatione and the Short Treatise at Rijnsburg, a village near Leiden, to which he had moved in about 1660. It was at Rijnsburg also that he began work on his first published book, a geometrical version of the first two parts of Descartes’s Principia Philosophiae, together with an appendix of ‘Metaphysical Thoughts’ (Cogitata Metaphysica), published in Amsterdam in 1663. Spinoza’s version of Descartes’s Principia is purely expository, and the Cogitata Metaphysica is as it were a Cartesian exercise, dealing with traditional problems of metaphysics in a Cartesian way (G i, 131). By the time that he wrote this book, Spinoza was already severely critical of Descartes, and it is not surprising that he should have said, ‘I do not acknowledge as my own everything that is contained in this treatise’.16 However, this does not mean that he rejected everything that the work contains. The author of the preface to the book (Spinoza’s friend Lodewijk Meyer) stated that ‘He judges some of it to be true’ (G i, 131), and indeed several passages in Spinoza’s mature works refer to his geometrical version of Descartes or to the Cogitata Metaphysica as expressing his own views.17 All this is consistent with the view of Spinoza stated at the beginning of this chapter: namely, that he is the reformer of the Cartesian philosophy, not its destroyer. Spinoza left Rijnsburg in April 1663 and moved to Voorburg, a village near the Hague. In 1670 he moved to the Hague itself, where he continued to live until his death from consumption on 21 February 1677. Between 1663 and 1677 Spinoza wrote the works for which he is most famous. He seems to have begun work on his masterpiece, the Ethics, whilst still at Rijnsburg; certainly, he sent the first propositions of what appears to be a draft of the book to his friends in Amsterdam in February 1663 (Ep 8). By June 1665 a draft of the work was near completion. At that stage, incidentally, the work consisted of three parts; the third of these was later expanded into what became Parts Three, Four and Five of the final version. However, Spinoza suspended work on the Ethics in the latter half of 1665 (Ep 30; to Oldenburg, September/October 1665), so that he could concentrate on a book which was to be published in 1670 as the Tractatus Theologico-Politicus. In this book, Spinoza aimed to show (contrary to the views of the Dutch Calvinists) that the Scriptures are compatible with freedom of thought. In pursuit of this end he offered one of the first critical accounts of the Bible, presenting it as a historical document. The book was published anonymously and under a false imprint, but its authorship was widely known and Spinoza was attacked in print by numerous defenders of religious orthodoxy. After 1670 Spinoza returned to work on the Ethics, and by July 1675 it was complete (Ep 68). However, Spinoza thought it advisable to delay publication, and the work did not appear until after his death, as part of his posthumous works. These appeared in December 1677 (G ii, 313–4) in both the Latin original and a Dutch translation.18 They contained, besides the Ethics, the Tractatus de Intellectus Emendatione, an unfinished Tractatus Politicus on which Spinoza was working during his last years, an incomplete Compendium of Hebrew Grammar, and those items of Spinoza’s correspondence which his editors believed to be of philosophical importance. The correspondence of Spinoza is valuable, not only for the philosophical arguments that it contains, but also for the light that it throws on his interests, and so indirectly on his philosophy as a whole. I have argued that Spinoza owed much to Descartes; now, Descartes’s philosophy was closely connected with the science of his time, and it is therefore not surprising that Spinoza’s letters should display an interest in science. Of the eighty-seven letters to or from Spinoza that have survived,19 nineteen touch on scientific or mathematical issues.20 That some of these—Ep 36, 39, 40, 46—should deal with problems of optics, and more specifically with problems concerning lenses, is not surprising; it is well known that Spinoza, after his expulsion from the synagogue, supported himself by grinding and polishing lenses. But other letters display an interest in science that is not purely professional. Spinoza corresponds with Robert Boyle about nitre, fluidity and firmness (Ep 6, 11, 13, 16); he discusses with the secretary of the Royal Society, Henry Oldenburg, recent work on comets (Ep 29–32) and Descartes’s theories about the planets (Ep 26); he comments on Descartes’s laws of motion and Huygens’s criticism of these, and asks for news of an experiment carried out in the Royal Society to test a hypothesis of Huygens (Ep 32, 33); he discusses the calculation of chances (Ep 38) and reports on an experiment of his own about pressure (Ep 41). This interest in the sciences is confirmed by a list of books from his library that were put up for sale after his death.21 Of the 161 books listed, roughly a quarter are mathematical or scientific works.22 To sum up, my aim has been to determine the intellectual context within which Spinoza’s thought is to be placed. I have argued that there is no reason to believe that Spinoza was deeply imbued with the Jewish or Christian philosophy of the Middle Ages. He may occasionally quote the medievals in order to make a point, but they are not the well-spring of his philosophy. His interest is not in old philosophical ideas, but in modern ones, in particular the philosophy of Descartes, which he ‘reforms’, and the new science of his time. I have spoken of Spinoza’s interest in contemporary science; before going further into his philosophy, something must be said in general terms about the way in which he saw the relations between science and his philosophy. It is a commonplace that, whereas Descartes was chiefly concerned with the answer to the question, ‘What do I know, and how do I know it?’, Spinoza is chiefly concerned with the question, ‘What is a good life for a human being?’ It may be that had Spinoza lived longer the Ethics would not have had the dominant position in his output that it now has; it might have been accompanied, not only by a completed Tractatus Politicus, but by a revised and completed version of his treatise on method, a book on physics, and an introduction to algebra.23 Notwithstanding all this, there is no doubt that Spinoza’s initial and chief motive for philosophizing was a moral one. In the famous autobiographical opening of his Tractatus de Intellectus Emendatione, he writes:24 After experience had taught me that all the things which occur frequently in ordinary life are vain and futile; when I saw that all the things on account of which I was afraid, and which I feared, had nothing of good or bad in them except in so far as the mind was moved by them, I resolved at last to inquire if there was some good which was genuine and capable of communicating itself, and by which the mind would be affected even if all the others were rejected. Since the time of Hume,25 many philosophers have taken the view that there is a gap between questions of fact and questions of value, between ‘is’ and ‘ought’. Philosophers who take a contrary view, and argue that human nature is relevant to questions about the nature of what is morally good, are termed ‘naturalists’. Spinoza is such a naturalist. He argued that if we are to discover the kind of life that is good for a human being, we must discover the true nature of human beings, and that this implies seeing ourselves in the context of nature as a whole. Human beings, he says,26 follow the universal laws of nature; the position of man in nature is not that of a kingdom within a kingdom. One could summarize his view by saying (adapting a phrase used by A.J.Ayer)27 that man is a subject for science. More will be said of Spinoza’s views about science and philosophy in the course of this chapter, which is concerned with Spinoza’s metaphysics and theory of knowledge (see especially pp. 287–9); his views about ethics and politics will be discussed by Dr Blom in the next chapter. In discussing Spinoza, I shall take as my primary source his Ethics. This is his acknowledged masterpiece; a work of great range, covering not only moral philosophy but also metaphysics and theory of knowledge, besides containing the outlines of a system of physics and a theory of politics. The full title of the book is Ethics, demonstrated in geometrical order, and indeed the most immediately striking feature of the book is the geometrical order in which it is presented. It is worth noting that, in presenting his philosophy in this form, Spinoza is following a lead given by Descartes. The relevant topic here is Descartes’s distinction between ‘analysis’ and ‘synthesis’, and although this has already been discussed in a previous chapter,28 it will not be superfluous to return to it here. In Part II of his Discourse on Method, Descartes had written (CSM i, 120) that ‘Those long chains composed of very simple and easy reasonings, which geometers customarily use to arrive at their most difficult demonstrations, had given me occasion to suppose that all the things which can fall under human knowledge are interconnected in the same way.’ This might lead one to expect that Descartes would present his philosophy in geometrical form, and indeed in the Second Set of Objections to Descartes’s Meditations Mersenne suggested that this would be a worthwhile undertaking (CSM ii, 92). Descartes’s reply turns on that distinction between analysis and synthesis which has just been mentioned. The distinction goes back to classical Greek mathematics, and there is a famous account of it in the writings of Pappus (fourth century AD), which Descartes is known to have studied. Pappus states29 that In analysis, we assume as a fact that which we seek [to prove] and we consider what arises out of this assumption; then we consider what that follows from, and so on until, proceeding in this way, we come upon something which is already known, or is one of our principles. In short, in analysis we proceed back from what has to be proved to first principles (Descartes calls them ‘primary notions’: Reply to Second Objections, CSM ii, III). Synthesis, on the other hand, is the reverse of this; as Descartes explains (ibid.) one starts with first principles and demonstrates conclusions from them, employing ‘a long series of definitions, postulates, axioms, theorems and problems’. Descartes stated a preference for the analytic method, which was, he said, the method that he had used throughout the Meditations (CSM ii, 111). However, in response to Mersenne’s suggestion he concluded his reply to the Second Objections by arguing ‘in synthetic style’ for some of the propositions argued for in the Meditations. But he insisted (CSM ii, 113) that these proofs were not a substitute for the Meditations, and said indeed that the analytic reasoning used in that work was superior. Spinoza, on the other hand, clearly thought that the best way in which to discuss ethics was by means of the synthetic method. One naturally asks what Spinoza hoped to achieve by the use of this method; that is, what he thought he would gain by presenting his philosophy in the form of theorems, derived from definitions and axioms. The answer may seem to be obvious. Spinoza does not explain how he viewed axioms, but there can be no doubt that he would have agreed with the remarks made by his friend Lodewijk Meyer, in the Preface that Meyer wrote to Spinoza’s geometrical version of Descartes’s Principles. In that Preface, Meyer said (G i, 127) that axioms are ‘statements so clear and evident that all who simply understand correctly the words that they contain can in no way refuse their assent to them’. Axioms, in short, are self-evident truths, and Spinoza’s aim in the Ethics is to derive from these, by deductive means, other propositions whose truth is not self-evident. In this way, he will demonstrate the truth of these propositions.30 I said just now that this explanation of Spinoza’s use of the geometrical method may seem to be obvious. By this I did not mean that the explanation is wrong; I meant only that there is more to be said. Spinoza has a deeper reason for using the geometrical method, as can be seen from the Preface to Part III of the Ethics. Here (G ii, 138) Spinoza discusses his application of a geometrical method to human emotions, and contrasts his approach with that of those who ‘prefer rather to abuse and ridicule the emotions and actions of men than to understand them’. Such people, he says, will find it extraordinary that he should want to demonstrate with sure reasoning (certa ratione) what they merely condemn rhetorically. But, he continues, human emotions follow from the same necessity and power of nature as other things do, and ‘acknowledge certain causes through which they are understood, and have certain properties equally worthy of our knowledge as the properties of any other thing, the contemplation alone of which delights us’. This shows that Spinoza thinks that the geometrical method, although it is certainly a means of establishing truths, is more than that. The person who has grasped the reasoning of the Ethics, Spinoza claims, will not just know the truth of a number of propositions, but will understand why things are as they are. In short, Spinoza is concerned not just to establish truths but to offer explanations. That this is Spinoza’s view of the geometrical method is confirmed by his use of definitions in the Ethics.31 These definitions are usually stated in the form, ‘By…I understand…’; and this raises a problem. Spinoza is in effect saying that he proposes to take a term in such and such a way. Such definitions seem to be of the kind that is commonly called ‘stipulative’, and it is now usually held that (in the words of a modern textbook of logic) ‘a stipulative definition is neither true nor false, but should be regarded as a proposal or resolution to use the definiendum to mean what is meant by the definiens, or as a request or command’.32 Given that that is so, one may ask why one should accept Spinoza’s definitions. Why should we use words in the way that he tacitly requests or commands? Why play one particular language game, rather than another? To answer this question, it will be useful to consider first what Spinoza is excluding when he states his definitions. The terms that he defines are not words that he has invented; he uses terms that others had used, but he often uses them in a new way. So when he says something of the form ‘By…I understand…’, he is often excluding what some, and perhaps most, philosophers understood by the term defined. His reason for rejecting such definitions, and for defining terms in the way that he does, is made clear in the course of the definitions of the emotions in Part III of the Ethics. Here, Spinoza says that ‘It is my purpose to explain, not the meanings of words, but the nature of things.’33 What he is doing when he defines terms has a parallel in the practice of scientists, who sometimes coin completely new terms and sometimes use old terms in a new way—as when a scientist uses the word Velocity’ to mean, not just speed, but speed in a certain direction.34 Definitions form an integral part of the geometrical method, so what has just been said confirms the view suggested earlier: namely, that Spinoza uses the geometrical method not just to establish truths, but also to explain, to achieve understanding. This point will meet us again when we consider the distinctive way in which Spinoza uses the terms ‘true’ and ‘false’ (see pp. 296–7). At present, however, there is a further question to be raised. The idea that deductive reasoning can be used to provide explanations was by no means new with Spinoza, or indeed in the seventeenth century in general; on the contrary, it can be traced back as far as Aristotle. In the Posterior Analytics (I 13, 78 a38–b3) Aristotle explains the fact that all planets shine steadily by presenting it as the conclusion of a deductive, or more precisely a syllogistic, argument.35 This raises the question why Spinoza should have chosen to present his explanatory system in geometrical, rather than in syllogistic, form. The answer must surely be that he was influenced by the new science of his time. For this science, mathematics was the key to the understanding of nature. So, for example, Descartes had declared in his Principles of Philosophy (Pt II, 64; CSM i, 247) that the only principles that he required in physics were those of geometry and pure mathematics; to this one may add Spinoza’s observation, made in the Appendix to Part I of the Ethics (G i, 79), that truth might have lain hidden from the human race through all eternity had it not been for mathematics. As to the possibility of an explanatory system cast in syllogistic form, Spinoza would probably have agreed with Descartes that the syllogism is useful only as a means of instruction, which enables others to understand what their teachers already know, and that its proper place is in rhetoric, not in philosophy.36 From a discussion of Spinoza’s reasons for putting his philosophy in the form of a deductive system we turn now to an account of the system itself. I said earlier (p. 278) that Spinoza takes the view that, if one is to discover what is the genuine good for human beings, one must get to know their true nature; and further, that this implies seeing human beings within the context of nature as a whole. In the Ethics, Spinoza (following the synthetic method) starts from certain definitions and axioms which enable him to derive conclusions about the universe in general, and from these, with the help of further definitions and axioms, he derives a number of conclusions about the nature of human beings in particular, and about what is good for us. The first part of the Ethics is concerned with what Spinoza calls ‘God’. His first definition, however, is not of God, but of a ‘cause of itself—though it later emerges that to speak of God and of a cause of itself is to speak of one and the same being. Spinoza explains that by ‘cause of itself’ he understands ‘that whose essence involves existence; or, that whose nature cannot be conceived except as existing’. The term ‘essence’ plays an important part in the Ethics, though it does not receive a formal definition until Part II. In the first definition of Part I, Spinoza is implying that the predicate P (here, existence) belongs to the essence of S if one has to think of the nature of S as involving the predicate P.37 Some observations made by Descartes in his Notae in Programma quoddam (‘Comments on a certain Broadsheet’, Amsterdam 1648; CSM i, 297) are helpful here. The nature of contingent things, Descartes says, leaves open the possibility that they may be in either one state or another state, for example he himself may at present be either writing or not writing. But when it is a question of the essence of something, it would be quite foolish and self-contradictory to say that the nature of things leaves open the possibility that the essence of something may have a different character from the one it actually has. So it belongs to the essence of a mountain that it exists with a valley; or, as Spinoza would say, the nature of a mountain cannot be conceived except as existing with a valley. Let us now return to Spinoza’s definition of a cause of itself as that whose essence involves existence. This is reminiscent of what is commonly called the ‘ontological argument’ for the existence of God; and indeed, the definition of a cause of itself plays an important part (by way of Proposition 7 of Part I) in the first of Spinoza’s arguments for the existence of God in Proposition 11 of Part I. It is worth noting, however, that the term ‘ontological argument’ is used of two different arguments, which have in common the fact that they move from a definition of something to an assertion of the existence of what is defined. In the version which is familiar from Descartes’s fifth Meditation (CSM ii, 44–9) the argument is based on the definition of God as a most perfect being, together with the thesis that existence is a perfection. This is basically the same as the argument put forward by Anselm, in the eleventh century AD, in his Proslogion, although there the argument proceeds from the definition of God as ‘that than which nothing greater can be thought’.38 Spinoza, on the other hand, is arguing from the concept of a necessary being. His argument is that a necessary being is a being which has to be thought of as existing; and that which has to be thought of as existing, necessarily exists. It may be added that another seventeenth-century rationalist, Leibniz, put forward both versions of the argument, though he declared his preference for the second version.39 The concept of a cause of itself is interesting, not only for the relation that it has to Spinoza’s version of the ontological argument, but also because it illustrates his distinctive views about causality. Someone who (like Hume or Kant40) takes the view that a cause must precede its effect in time will find the concept of a cause of itself self-contradictory; for how can something first exist, and then cause its own existence? Spinoza, however, does not view causality in this way; his view is a version of what it is usual to call the rationalist theory of causality. According to this theory, to state the cause of X is to give a reason for X’s existence or nature. So much might be generally agreed, if this is taken to mean that to give a reason is to answer the question ‘Why?’, and that in stating the cause of something one is answering such a question. What is distinctive about the rationalist theory of causality is the view that, in giving such a reason, one is doing what geometers do when they state the reason for the truth of some geometrical proposition—as when, for example, it is said that the reason why the base angles of a certain triangle are equal is the fact that the triangle in question is isosceles. In such a case, the relation between the triangle’s being isosceles, on the one hand, and having base angles which are equal, on the other, is a timeless relation; and Spinoza takes the view that such a relation holds in every case of a cause-effect relation. This is what he means when, in the second proof of the existence of God in Proposition 11 of Part I of the Ethics, he uses the phrase ‘cause, or reason’ (causa seu ratio; G ii, 52–3), where ‘reason’ is used in the nontemporal sense that has just been described.41 This being so, to speak of a cause of itself is not to speak of that which exists before it produces itself; rather, it is to speak of that whose existence is self-explanatory. Why Spinoza should have taken this view of the nature of causality can only be conjectured, but it does not seem fanciful to relate his view to the science of his time. I have said already that this science was mathematical in character (p. 281); now, many causal propositions belong to the sciences, and it would have been tempting to see the causal propositions asserted by physicists as not different in kind from the propositions asserted by geometers, and from this to argue that absolutely all causal propositions are to be viewed in this way. It may be added that the influence of the rationalist theory of causality was still felt in the eighteenth century; certainly, Hume thought it worthwhile to refute the view that inferences from cause to effect are ‘demonstrative’, that is, that when one thing causes another, ‘the contrary is impossible, and implies a contradiction’.42 But there is no reason to believe that he was attacking Spinoza in particular.43 The ‘God’ whose existence is argued for in Proposition 11 of Part I of the Ethics is defined by Spinoza in a distinctive way. By ‘God’, he says (Ethics, Pt I, Definition 6), he understands a being which is absolutely infinite, that is, ‘a substance consisting of infinite attributes, each of which expresses eternal and infinite essence’. Superficially, there is nothing here to which any of Spinoza’s contemporaries might object (though the absence of any reference to God as creator might have caused some surprise). But from what is said about substance and its attributes in Part I of the Ethics, it becomes clear that the God defined by Spinoza is very different from the God of theism. This section will be concerned with Spinoza’s views about substance and attribute. There is no one philosophical problem of substance; rather, there are two main problems.44 These are: ‘What is it that really exists?’ and ‘What is it that remains the same when some change occurs?’ Spinoza’s theory of substance is concerned only with the first of these.45 In the third definition of Part I of the Ethics, Spinoza says of substance that it is ‘that which is in itself. A seventeenth-century reader would have seen this as involving concepts which go back to Aristotle. In Chapter 5 of the Categories Aristotle says that a substance is that which is ‘neither said of a subject nor in a subject’ (2 a11–13, trans. J.L.Ackrill). The first part of the definition is not important here (although it does matter in the case of the philosophy of Leibniz); what matters is the idea that a substance is not ‘in’ a subject. Aristotle explains (Categories, ch. 2, 1 a24–5) that, in this context, to say that something is in a subject is to say that it cannot exist apart from the subject. A substance, then, is something which has an independent existence. Spinoza means much the same when he says that a substance is ‘in itself’, with the difference that he maintains that a substance, though not dependent on anything other than itself, has to be regarded as self-dependent, by which he presumably means that its existence depends solely on its own nature. Spinoza adds (going beyond the account of substance in Aristotle’s Categories) that a substance is also conceived through itself. Once again, the idea of not being dependent on anything external is present. Spinoza is asserting that, in thinking of a substance, we do not have to think of anything else; that is, a substance is logically independent of anything else. The notion of something which is conceived through itself will re-emerge in the context of Spinoza’s theory of attributes. So far, Spinoza’s account of substance may seem to travel along a well-worn path.46 However, Spinoza forsakes this for a much less-used path when he considers the question, ‘What satisfies the criteria of a substance?’ For the Aristotle of the Categories there are many substances: this man, this horse and so on (2 a11–13). For Spinoza, on the other hand, there is and can be only one substance, and that substance is God. The argument for this conclusion that is contained in Proposition 14 of Part I of the Ethics is obscurely expressed, but it is clear that it rests on the concept of God as an infinite substance.47 The thrust of the argument is that God’s infinity as it were crowds out all other possible substances, God remaining as the one and only substance. Descartes, too, understood by ‘substance’ that which depends on no other thing for its existence, and said that there is a sense in which the only substance is God (Principles of Philosophy, Pt I, 51; CSM i, 210). However, he said that there is another sense of ‘substance’, in which we may call by the name of ‘substance’ that which depends for its existence only on God; in this sense, we may speak of corporeal substance and of created thinking substance.48 Spinoza will not allow this second sense of the word ‘substance’; indeed he would argue (as will be seen shortly) that, by using it, Descartes had rendered insoluble the problem of the relations between mind and matter. In place of corporeal and thinking substances, Spinoza refers to ‘extension’ and ‘thought’, and says that these are not substances but are attributes of the one substance. Spinoza defines an attribute in the fourth definition of Part I of the Ethics as ‘that which the intellect perceives of substance as constituting its essence’; he also speaks of the attributes as ‘expressing’ the essence of substance.49 In mentioning the intellect in his formal definition of an attribute, Spinoza has seemed to some scholars to make the relation between substance and attribute a subjective one; the intel-lect has been thought to impose attributes on a substance which is in reality without them. This, however, is surely wrong. From the mass of evidence that has been brought against the subjectivist interpretation,50 it will be sufficient to cite a remark contained in the proof of Proposition 44 of Part II. Here, Spinoza says that ‘It is of the nature of reason to perceive things truly… namely,…as they are in themselves.’ If, as is reasonable, one equates the ‘reason’ that is mentioned here with the ‘intellect’ mentioned in the definition of an attribute, then Spinoza is saying that, if the intellect perceives X as constituting the essence of substance, then X does indeed constitute the essence of substance. In the first part of the Ethics, Spinoza’s discussion of the attributes is carried on in quite general terms; nothing is said expressly that enables the reader to say that this or that is an example of an attribute.51 Only in the first two propositions of Part II are we told that, of the infinite attributes that God has, two are extension and thought.52 Two points must be noted here. First, it must be realized that the attributes of extension are not abstractions, even though Spinoza uses abstract nouns to refer to them. Spinoza makes it clear that to speak, for example, of the attribute of extension is to speak of God as extended, God as an ‘extended thing’ (Ethics, Proposition 2 of Part II). Second, each attribute (by Definition 6 of Part I) is infinite; so to talk about extension is to talk about an extended reality that is infinite. In saying that extension and thought express the essence of substance, Spinoza obviously means that each is of fundamental importance to our understanding of reality. What is perhaps not so obvious is that his views about attributes are not entirely at variance with those of Descartes. When Descartes spoke of corporeal and thinking substance, he implied that each has many attributes (Principles of Philosophy, Pt I, 53; CSM i, 210), understanding by an attribute (ibid., Pt I, 56) that which always remains unmodified, such as existence and duration in the case of created things. Each substance, however, has one ‘principal attribute’, and these are extension in the case of corporeal substance and thought in the case of thinking substance. Spinoza and Descartes, then, agree in holding that one must explain physical nature in terms of extension and mental states and events in terms of thought. They also agree to some extent (though here there are also important differences) that we must explain the former in terms of extension alone and the latter in terms of thought alone. Descartes expresses this by saying (Meditation VI, CSM ii, 54) that corporeal and thinking substance are ‘really distinct’.53 Spinoza would say that Descartes was right in holding that we cannot mix mental terms with physical terms when we try to explain either mind or matter—still less can we reduce mental terms to physical terms (as in the case of materialism) or physical terms to mental terms. But, he would say, the metaphysics in terms of which Descartes made this point was seriously at fault. Contrary to Descartes, there is only one substance, and what Descartes says in terms of two substances must be translated into terms of the attributes of thought and extension, each of which is ‘conceived through itself’.54 Spinoza would also argue that by regarding thought and extension in this way —as self-enclosed attributes, which are attributes of one substance—he can solve a problem which had faced Descartes: that of the relation between mind and body. Descartes wanted to maintain two theses: first, that corporeal and mental substance are really distinct, but second, that mind and body act on each other, and indeed that the human being is a unity of mind and body. The problem for Descartes was to explain how these propositions can both be true, and Spinoza thought (as many others have thought) that he failed to do so. To grasp Spinoza’s solution, however, it is necessary to go further into his system. This is because the problem is one which concerns particular minds and particular bodies, and this means that one has to see how Spinoza accommodates these within his system. That is, it is necessary to consider his theory of ‘modes’. Spinoza argues, not only that the infinite substance must be unique, but that it must also be indivisible, and that the same can be said of any of its attributes.55 This raises the question of how the indivisible substance, or its indivisible attributes, is to be related to the particular things that we meet in our experience. That is, it raises the question: what is the place of the concept of a particular thing in Spinoza’s system? The answer is that it enters by way of the concept of a ‘mode’. Particular things, Spinoza says, are simply ‘modes by which attributes of God are expressed in a certain and determinate manner’.56 Spinoza has already defined a mode in the fifth of the definitions of Part I of the Ethics, saying that it is ‘that which is in something else, through which it is also conceived’. This definition can be illuminated by relating it to what Descartes has to say about real and modal distinctions. For Descartes, a real distinction holds between two or more substances, and is recognized by the fact that one can be clearly and distinctly understood without the other (Principles of Philosophy, Pt I, 60; CSM i, 213). A mode, on the other hand, cannot be understood apart from the substance of which it is a mode. ‘Thus there is a modal distinction between shape or motion and the corporeal substance in which they inhere; and similarly, there is a modal distinction between affirmation or recollection and the mind’ (ibid., Pt I, 61; CSM i, 213). Although Spinoza rejects the idea that there can be a real distinction between substances, he accepts the distinction between a mode and that of which it is a mode, the only difference from Descartes being that Spinoza’s modes are modes of the one substance, or of its attributes. He is saying in effect that when we talk about particular things, then (even though there is in a sense only one being, God) we are not indulging in mere fantasy. What would be a mistake, and a serious one, would be to regard as independent substances what are in fact modes of the one substance. What makes Spinoza’s concept of a mode more than just a terminological exercise is the use to which he puts it. It will be convenient to begin by considering his views about the modes of the attribute of extension, where the line of thought is easier to follow. In the first definition of Part II of the Ethics, Spinoza explains that by a ‘body’ he understands a mode of the attribute of extension. (This, incidentally, is a good example of his use of definitions. By calling a body a ‘mode’, he claims, we understand what a body really is.) A body, then, is distinct from another body in that they are different modes of one and the same attribute. To explain the precise way in which they differ, Spinoza inserts in the Ethics, between the Scholium to Proposition 13 of Part II and the next proposition (G ii, 97–102), a sketch of a theory of physics. He takes it as axiomatic that all bodies either move or are at rest, and that each body moves now more slowly and now more quickly. What differentiate bodies (Lemma 1) are differences in respect of motion and rest, speed and slowness; and these are modal differences. Spinoza singles out motion and rest for special mention, saying that they follow from the absolute nature of the attribute of extension, and exist for ever and infinitely.57 This means in effect that motion and rest (which scholars call an ‘immediate infinite mode’ of extension) are universally present in matter, and are of fundamental importance for the physicist. Spinoza goes on to say that those bodies which are differentiated only by motion or rest, speed or slowness, may be called ‘most simple bodies’ (Axiom 2 after Lemma 3). These corpuscles are the basic building-blocks of Spinoza’s system of physics; they correspond roughly to atoms,58 with the difference that Spinoza’s ‘most simple bodies’ are modes, not independent substances. The most simple bodies combine to form groups (Definition after Lemma 3), and each such group is called by Spinoza one body, or an ‘individual’. An individual has a certain structure, and as long as that structure is preserved, we say that the individual is the same. (This, incidentally, has a bearing on one of the two problems of substance mentioned on p. 284—namely, the problem of what it is that remains the same when change occurs). Individuals are of varying complexity, culminating in an individual of infinite complexity—that is, the whole of nature, ‘whose parts, that is, all bodies, vary in infinite ways without any change of the individual as a whole’ (Scholium to Lemma 7). In Epistolae 64 Spinoza calls this individual the ‘aspect of the whole universe’ (facies totius universi). Scholars refer to it as a ‘mediate infinite mode’—mediate, because it depends on motion and rest. Spinoza seems here to be thinking of the whole physical universe as manifesting some general law—perhaps that of the overall preservation of the same ratio of motion to rest.59 All this throws light on the way in which Spinoza saw the relations between science and philosophy. I have mentioned (p. 277) Spinoza’s deep interest in the science of his day; but this does not mean that he accepted without question the propositions of contemporary science, and tried to generalize from them.60 I have indeed suggested (p. 281) that his preference for a geometrical order in philosophy was influenced by the mathematical physics of his time. But this merely explains his preference for one sort of explanatory deductive system— one cast in the form of a work of geometry—over another kind, cast in the form of syllogisms. It does not imply that he thought it impossible to provide a rational justification of the truths of science. In his view, such justification would on the whole proceed in the way that metaphysical truths are justified—namely, by deduction from self-evident truths. In sum, science for Spinoza is not something on whose conclusions philosophers merely reflect; rather, philosophy is needed in order to justify the propositions of science. I said just now that Spinoza thought that scientific propositions could ‘on the whole’ be justified by deducing them from self-evident truths. The type of corporeal ‘individual’ which is of most interest to him, as a moral philosopher, is of course the human body. Now, Spinoza’s account of the human body is based on a number of ‘postulates’ (indeed, the assertion that the human body is a highly complex individual is itself a postulate: see Postulate 1 after Lemma 7). By a ‘postulate’ Spinoza means a proposition which is assumed to be true, but which does not have the self-evidence that belongs to axioms. The question is why a postulate should be assumed to be true. Spinoza’s answer is contained in an assertion made later (Scholium to Proposition 17 of Part II) that his postulates contain hardly anything that is not borne out by experience. This raises the question of the place that Spinoza gives to experience in his system; but before this can be discussed (pp. 297–9 below) it is necessary to consider his account of the modes of thought. When Spinoza says that a body is a mode of the attribute of extension he can be regarded as adapting, to his own theory of substance, Descartes’s views about corporeal substance. For there are indications that Descartes held that there is just one corporeal substance, whose parts are distinguished only modally.61 But where the human mind is concerned, the situation is very different. Descartes believes that every human mind is a substance—more specifically, a thinking substance—and such a plurality of substances is something that Spinoza cannot allow. For him, the human mind has to be viewed in terms of the concept of mode. To talk of the human mind is to talk of something complex (Proposition 15 of Part II of the Ethics), just as to talk of the human body is to talk of something complex. In the case of the mind, the basic units are again modes, but modes of the attribute of thought. Spinoza calls these modes ‘ideas’.62 In what he says about ‘ideas’, Spinoza is opposing Descartes. Descartes had introduced his sense of the term in the third of the Meditations, in which he said (CSM ii, 25) that ideas are those thoughts which are ‘as it were the images of things…for example when I think of a man, or a chimera, or the sky, or an angel, or God’. The force of the phrase ‘as it were’ is that one cannot have a genuine mental picture of an angel or of God; however, it does seem that for Descartes an idea is at any rate picture-like, and that it is an entity which the mind perceives, as distinct from the activity of perceiving. So, for example, in his reply to the third Objections, Descartes explains (CSM ii, 127) that the word ‘idea’ means ‘whatever is immediately perceived by the mind’. Spinoza, on the other hand, insists that an idea is an activity. In his definition of an idea in Definition 3 of Part II of the Ethics, he says that an idea is a ‘conception’ (conceptus) of the mind, and adds that he prefers the term ‘conception’ to ‘perception’ because the former term ‘seems to express an action of the mind’. It emerges later63 that, when Spinoza speaks of an action of the mind here, he means that to have an idea of X is to think of X, in the sense of making a judgement about it, that is, affirming or denying something of it. It may be added that in using the term ‘idea’ in this way Spinoza is not being innovative, but is taking up a suggestion which Descartes had put aside. In the Preface to the Meditations (CSM ii, 7) Descartes had said that the term ‘idea’ could be taken to mean an operation of the intellect, but went on to say that this was not how he proposed to use the word. It emerges from what is said later in the Ethics that Spinoza has two chief reasons for preferring his definition of the word ‘idea’. Briefly, these are as follows: (i) Descartes’s sense of the term forms part of a mistaken theory of judgement. Descartes believed that two faculties are involved, namely the intellect and the will (Meditation IV; CSM ii, 39). Spinoza, on the other hand, argues64 that the two are the same. To think of something (i.e. to have an idea of something) is to make a judgement about it; for example, to think of a winged horse is to affirm wings of a horse, (ii) Descartes is unable to explain our knowledge of the truth; for how can we know that a true idea agrees with that of which it is the idea?65 All this is intelligible as a criticism of Descartes, but Spinoza’s own views raise a problem: namely, that of the way in which an idea, as a mode of thought, is related to the attribute of thought. The problem springs from the infinity of the attribute of thought. In what sense, one asks, can an idea which a particular person has be called a mode of this infinite attribute? One might perhaps suggest that (by analogy with the attribute of extension and its modes) Spinoza views the attribute of thought as some kind of infinite mind-stuff; but it is not at all clear what might be meant by such a stuff. It may be that some light is thrown on the problem by Spinoza’s theory of truth, which is discussed on pp. 296–7. To anticipate, Spinoza holds that a true idea fits, and a false idea does not fit, into an explanatory system, and it may be that the relation between an idea and its attribute has to be conceived along such lines. However, perhaps enough has been said here about Spinoza’s theory of ideas to enable one to grasp his answer to the problem posed on p. 287—the problem of mind-matter relations. It will be recalled that the problem arose for Descartes because he wanted to maintain two propositions. On the one hand, he wanted to say that mind and body are ‘really distinct’; on the other hand, he felt compelled to grant that, despite this, mind and body act on one another, and indeed that the human being is a unity of mind and matter. Spinoza’s answer to the problem is given in terms of his theory of attributes and modes. In effect, he holds that Descartes was right in saying (Reply to First Objections, CSM ii, 86) that one has a complete understanding of what a body is without ascribing to it anything that belongs to the nature of a mind, and conversely in the case of a mind. Descartes’s error, Spinoza would say, lay in his supposition that there must exist substances of basically different kinds, namely mental and corporeal substances. Really, there exists just one substance with different attributes, each of which (and here Spinoza expresses a qualified agreement with Descartes) must be ‘conceived through itself’. It is because the attributes are conceived through themselves that we must explain physical states and events in physical terms only, and mental states and events in mental terms only. Yet the human mind and body are not wholly unrelated; for any state of or event in the one there is a corresponding state of or event in the other. This is because thought and extension are different attributes of one and the same substance. As Spinoza puts it in an important note to Proposition 7 of Part II of the Ethics, A mode of extension and the idea of that mode are one and the same thing, but expressed in two ways…. For example, a circle existing in nature and the idea of an existing circle…is one and the same thing, though explained through different attributes. In Proposition 2 of Part III of the Ethics, Spinoza observes that it follows from what he has said about the nature of the attributes that ‘The body cannot determine the mind to think, nor the mind the body to motion, nor to rest.’ As he recognizes, this may seem paradoxical. Suppose, for example,66 that some craftsman is building a temple; surely the craftsman’s mind must guide the movements of his hands? Spinoza replies that this cannot be so, and that people only suppose that it must be so because ‘they know not what a body can do, or what can be deduced from mere contemplation of its nature’. He goes on to hint that, when people think of the capabilities of the human body, they tend to think in terms of the machines they can construct. But ‘the construction of the human body (corporis humani fabrica67)…far surpasses any piece of work made by human art’. So (Spinoza implies) there is no reason to think that the movements of the craftsman’s hands cannot be explained in purely physical terms. Spinoza’s theory of the relations between mind and body is often, and with some justice, said to be a form of ‘psycho-physical parallelism’. By this is meant the view that body does not act on mind, nor mind on body, but that the states of mind and body are such that for each bodily state there is a corresponding mental state and conversely; and similarly for bodily and mental events. However, to describe Spinoza’s theory of mind-body relations in this way does not identify it completely. This is because to talk of psycho-physical parallelism is to talk, not of one theory, but of a group of theories. One could say, for example, that Leibniz’s theory of pre-established harmony,68 as applied to the relations between mind and body, is a form of psycho-physical parallelism; but Leibniz’s theory of mind-body relations is very different from Spinoza’s. To categorize Spinoza’s theory more precisely, we have to consider his answer to the question why the parallelism should hold. The answer, as we have seen, is that each attribute is not only ‘conceived through itself but is also an attribute of one and the same substance. Seen in this way, Spinoza’s theory of the relations between mind and body is a classical form of what is often called the ‘double-aspect theory’.69 This theory is clearly defined in Baldwin’s Dictionary of Philosophy and Psychology (London, 1901) as the theory which states that ‘mental and bodily facts are parallel manifestations of a single underlying reality’. The theory professes to overcome the onesidedness of materialism and idealism by regarding both series as only different aspects of the same reality, like the convex and the concave views of a curve; or, according to another favourite metaphor, the bodily and the mental facts are really the same facts expressed in different language. Spinoza never calls an attribute an ‘aspect’ of substance; however, he often describes the relation between substance and attribute in terms of expression (cf. pp. 285–6), and it has just been noted (p. 292) that he says expressly that a mode of extension and the corresponding mode of thought are ‘one and the same thing, but expressed in two ways’. What Spinoza has to say about the relation between God and his modes is intimately connected with what he has to say about God as a cause. It has already been seen that God is self-caused, causa sui (p. 282); but Spinoza also says that God is the efficient cause of all modes. His reason for saying this70 is that an infinity of modes follows from the necessity of the divine nature. Now, by virtue of Spinoza’s thesis that the causal relation is a logical relation (p. 283), this is the same as saying that God is the cause of an infinity of modes. In calling God an ‘efficient cause’, Spinoza is using traditional terminology, which goes back to Aristotle. Such a cause, according to Aristotle, is a source of change or coming to rest (Physics II, 3, 194 b29–32). So, for example, a man who gave advice is a cause in this sense, and a father is the efficient cause of his child. In these cases, the cause is outside the effect, and of course Spinoza’s substance, God, is not outside the modes. However, this does not prevent Spinoza from calling God the efficient cause of what is in him; God, as he explains in a letter (Ep 60, G iv, 271) is an internal efficient cause, or, as he says in Proposition 18 of Part I of the Ethics, God is the ‘immanent’ cause of things. This means that Spinoza has to reject the idea of a creative deity, as understood by theistic philosophers.71 Efficient causality was traditionally distinguished from ‘final’ causality. A ‘final’ cause, for Aristotle, is the end or purpose for the sake of which something is done—as, for example, health is the cause of taking a walk (Physics II, 3, 194 b32–195 a3). Spinoza insists that, although we can and indeed must think of God as an efficient cause, we cannot ascribe final causality to God. In this respect he is in partial agreement with Descartes. In the Principles of Philosophy, Descartes had declared that ‘It is not the final but the efficient causes of created things that we must inquire into’ (Pt I, 28; CSM i, 202). So far, Spinoza would have agreed; but he would not have agreed with Descartes’s reason for the assertion. Descartes does not deny that God has purposes, but is content to say that we cannot know God’s purposes (ibid.; cf. op. cit., Pt III, 2; CSM i, 248). For Spinoza, on the other hand, the notion of a purposive God has no sense. Such a concept, he says, would be inconsistent with the perfection of God;72 for if God were to act on account of an end, he would necessarily be seeking something that he lacks (Appendix to Part I of the Ethics, G ii, 80). But, as an absolutely infinite being, God can lack nothing. Not only does Spinoza think that the concept of final causality cannot be applied to God, but he also thinks that it cannot be applied to finite beings such as ourselves. This thesis is not only of intrinsic interest, but also leads to a deeper understanding of Spinoza’s views about God’s causality. Spinoza would concede that finite beings, unlike God, can in a sense be said to have purposes; but, he would say, such purposive activity has to be explained in terms of efficient causation. In order to understand Spinoza’s position, it is necessary to consider what he says about the ways in which things follow from God as a cause. He says that some modes follow from the absolute nature of God; these are the socalled ‘infinite modes’ (cf. pp. 288–9). Finite modes, on the other hand, cannot follow from the absolute nature of God (for that would make them infinite); instead, they must be determined by God, in so far as God is conceived as modified by some mode (Ethics, Pt I, Proposition 28). The upshot of this is (ibid.) that each particular thing is determined by some other particular thing, and that by another, and so on to infinity. This may seem to make each finite mode the helpless plaything of external forces—something which is merely pushed about. But in an important note to Proposition 45 of Part II, Spinoza indicates that this is not so. This note shows that there is a dual causality in God, or that there are two distinct ways in which a thing’s existence and nature follows necessarily from something else. What Spinoza says is that although each particular thing is determined by another to exist in a certain way, yet ‘the force wherewith each of them persists in existing follows from the eternal necessity of the nature of God’. This force or power73 is something which is usually referred to as ‘conatus’ (literally, ‘endeavour’). Spinoza is here anticipating the important sixth proposition of Part III of the Ethics, which states that ‘Each thing, in so far as it is in itself (quantum in se est) endeavours to persist in its own being.’ The phrase ‘is in itself echoes Spinoza’s definition of substance in Definition 3 of Part I (cf. p. 284), and serves to connect Proposition 6 of Part III with the Scholium to Proposition 45 of Part II, which was discussed in the last paragraph. For since there is only one substance, Proposition 6 of Part III must be taken to mean that each thing endeavours to persist in its own being in so far as it is God—or (to use the language of the Scholium to Proposition 45 of Part II) in so far as it ‘follows from the eternal necessity of the nature of God’. This concept of conatus is central to Spinoza’s moral philosophy, and a detailed discussion of it belongs to the next chapter. But it is worth noting here that, for Spinoza, each particular thing— and not just the very complex things that we call living beings— endeavours, in so far as it is ‘in itself, to persist in its own being. So when Spinoza says, in the Corollary to Lemma 3 of Part II of the Ethics, that ‘a moving body continues in motion until determined to rest by another body’, this may be regarded as an example of conatus —namely, the kind that is displayed by a ‘most simple body’. What is most striking about Spinoza’s views concerning the causality of God is the extreme form of determinism that they display. We have already seen several respects in which Spinoza’s God differs from the God of the theist: how God, although an efficient cause, does not create the universe from nothing, and how God cannot act for an end. But there is another major difference. The God of the theist creates freely: that is, God chooses to create, and could have chosen differently. God’s freedom of choice was something on which Descartes laid great stress; Spinoza, on the other hand, says74 that God does not act out of free will, but that things could not have been produced by God in any other way or order from that in which they were produced. This means that there is no objective justification for calling things contingent. Just what Spinoza is claiming here can be seen from the way in which he argues for his conclusion. We know that, if B is caused by A, then B follows necessarily from A. Now, everything is, in the last analysis, caused by God, that is, follows necessarily from him; but God (by Proposition 11 of Part I of the Ethics) exists necessarily. Therefore everything that exists cannot but exist, and in the way that it does; or to put this in another way, strictly speaking no other world order is conceivable. More than this, Spinoza argues that whatever we conceive to be in God’s power (i.e. whatever is logically possible) necessarily exists (Ethics, Pt I, Proposition 35). From this it follows that, if something does not exist, then it is impossible that it should have existed. In calling this an extreme form of determinism, I meant that Spinoza is not content to say that given a certain set of laws, and given an initial state of the universe, then absolutely all states of the universe can in principle be inferred from these. Such a position is consistent with the supposition that there could have been other laws, or that the initial state of the universe could have been different. For Spinoza, on the other hand, both the laws and the initial state are necessary, in the sense that no others are strictly speaking thinkable. Spinoza’s chief concern in the Ethics is with the human being, and more specifically with the human mind. It has already been seen that Spinoza, contrary to Descartes, argues that the human mind is not a substance; on the positive side he argues that, just as the human body is something highly complex, so also is the human mind. More precisely, the human mind is an idea which is composed of many ideas (Ethics, Pt II, Proposition 15). Spinoza’s account of the human mind is much more elaborate than his account of the human body, and falls into two main sections. The first of these, which occupies much of Part II of the Ethics, concerns topics which belong to the theory of knowledge—namely, the nature of a true idea, and of the kinds of knowledge. The second section, which begins in the course of Part III, concerns the human mind as something which is appetitive and has emotions. Our primary concern in this chapter is with the topics that belong to the theory of knowledge. Spinoza speaks both of ‘true ideas’ and ‘adequate ideas’; these are closely related. He says of a true idea that it must ‘agree with’ its object; an adequate idea is a true idea which is as it were abstracted from its relation to its object and considered only in respect of its internal properties.75 In speaking of truth as ‘agreement’, Spinoza might seem to have in mind some version of the correspondence theory of truth. It will be recalled that, for Spinoza, to have an idea involves making a judgement (p. 290); so one might suppose him to mean that my idea of (say) an existent Peter is true when my judgement that Peter exists corresponds to a certain fact, namely, Peter’s existence. In fact, however, this is not so; when Spinoza speaks of a true idea he is speaking not so much of truth as of knowledge. Perhaps the first hint of this is given in Proposition 43 of Part II of the Ethics, where Spinoza says that ‘He who has a true idea, knows at the same time that he has a true idea.’ This may seem to be a glaring error; Plato, one may object, was obviously right when he said (Meno, 97a) that to have a true belief that this is the road to Larissa is not the same as knowing that this is the road to Larissa. However, the appearance of paradox vanishes when it is realized that Spinoza is using the term ‘true’ in a special sense. A passage from the early Tractatus de Intellectus Emendatione is relevant here. Spinoza says (G ii, 26) that If anyone says that Peter, e.g., exists, but does not know that Peter exists, his thought is, as far as he is concerned, false— or, if you prefer, is not true —even though Peter really does exist. The assertion ‘Peter exists’ is true only with respect to a person who knows for certain that Peter exists.76 That this was also Spinoza’s view in the Ethics is indicated by the note to Proposition 43 of Part II, which states that to have a true idea is to ‘know something perfectly or in the best way’. When Spinoza says in the Ethics, therefore, that a person who has a true idea knows that he has a true idea, he is not saying something that is inconsistent with what Plato had said about knowledge and true belief; what he is saying is that the person who knows, knows that he knows. There is more to be said about Spinoza’s views concerning knowledge and truth. In the note to Proposition 43 of Part II of the Ethics that has just been cited, Spinoza says, not just that to have a true idea is to know, but that it is to know something ‘perfectly or in the best way’ (perfecte sive optime). Here, he is referring to a point already made in Part II of the Ethics (Note 2 to Proposition 40)—namely, that there are various kinds of knowledge.77 Now, from what he says about these kinds of knowledge it emerges that it is possible to have knowledge of a sort—knowledge which is not perfect—without having a true idea, in that the idea that one has is only inadequate. The suggestion that one can know that p, even though the proposition that p is not true, may seem to be yet another paradox. However, a consideration of what Spinoza has to say about the kinds of knowledge shows that the paradox is only apparent. In the note just mentioned, Spinoza says that there are three kinds of knowledge, which he calls respectively ‘imagination’, ‘reason’ and ‘intuitive knowledge’. The first of these is the one that is relevant to the topic now at issue, and will concern us in the rest of this section. ‘Imagination’ includes particular propositions that are based on sense experience and general propositions which are derived by induction from particular instances.78 Spinoza says that such knowledge is knowledge from what one may render as ‘uncertain’ or ‘inconstant’ (vaga) experience. By this he means (ibid.) that the ideas involved are fragmentary and without rational order; he also says that they are ‘inadequate and confused’ (Proposition 41 of Part II). This means, then, that there is a kind of knowledge—namely, imagination—which involves inadequate or false ideas. Light is thrown on this by Spinoza’s remark (Ethics, Pt II, Proposition 28) that confused ideas are ‘like consequences without premises’. What Spinoza means may be explained as follows. Suppose that I see a certain pen in front of me; suppose, too, that there really is a pen there—i.e. no sense illusion is involved. Now, my seeing this pen is the result of a complex set of causes; but in so far as I merely see the pen, I am unable to trace these causes. That is, I am unable to give an explanation of what it is for me to see this pen. So although I know that there is a pen there (more of this later) I have only an inadequate idea of the pen. If I am to have an adequate idea of it, I must make use of knowledge which does not rest on sense experience alone. For example, I must make use of physics, to explain the relation between the pen and my sense organs and brain, and I must also make use of metaphysics, to explain the relation between a corporeal state and the corresponding idea. Another sort of imagination recognized by Spinoza is knowledge based on induction. His account of this is very brief but appears to proceed along lines that are similar to his account of sense experience. Just as there is knowledge that rests on sense experience, so there is knowledge that rests on induction; indeed, in the Tractatus de Intellectus Emendatione Spinoza says that such knowledge is of great importance in everyday life (G ii, 11). One may infer that Spinoza regards such knowledge as defective in that it does not give us any satisfactory explanation of why the inductive generalization holds. It tells us (say) that oil feeds a fire, but does not tell us why it does so. It is clear from all this why Spinoza should regard sense experience and induction as involving inadequate ideas; what is not so clear is why he regards them as providing us with knowledge. Some indication of an answer is provided by the note to Proposition 17 of Part II of the Ethics, already quoted on pp. 291– 2. In this, Spinoza defends his postulates on the grounds that they contain scarcely anything that is not borne out by experience. This itself may seem to stand in need of justification, in view of the attacks on the reliability of sense experience contained in the first and sixth of Descartes’s Meditations, and in fact Spinoza attempts to provide this. What he says is that we may not doubt of experience ‘after having shown that the human body as we sense it exists’. Spinoza is in effect saying that sense experience may not be doubted once it has been backed up by sound science and sound metaphysics, that is, once we realize that sense experience is the expression in the attribute of thought of that which, in the attribute of extension, consists of causal processes involving the percipient’s body and the external world.79 What Spinoza says about imagination, and in particular what he says about sense experience, is important in that it serves to correct the impression that he believes that human beings, in their search for knowledge, could in principle proceed in a purely a priori way, in the sense that all they have to do is to deduce consequences from definitions and axioms. The passage just quoted, in which Spinoza supports his postulates by an appeal to sense experience, shows that this is not so, and this is confirmed by an early letter (Ep 10, c. March 1663). In this, Spinoza says that we need experience in the case of those things ‘which cannot be inferred from the definition of a thing, as e.g. the existence of modes’. What he seems to mean is that (say) the true proposition that there is a pen in front of me is something that cannot be established by deductive means; if its truth is to be known, it can only be by means of sense experience. Spinoza, then, is not advocating arm-chair science; for him, experience has an important part to play in the acquisition of knowledge. At the same time, however, he would insist that, if we are to obtain the explanations that we seek, we must be able to place the data of experience within the context of a deductive system, whose axioms are self-evident. The second and third kinds of knowledge—‘reason’ and ‘intuitive knowledge’—are said to involve adequate ideas (Ethics, Pt II, Proposition 41). This means that (unlike imagination) they do not present us with conclusions that are cut off from their premises. In the case of ‘reason’, Spinoza says that it is the kind of knowledge that we have when we possess ‘common notions and adequate ideas of the properties of things’, and derive valid conclusions from them.80 The term ‘common notions’ was in general use in Spinoza’s time to refer to axioms;81 for example, in the deductive arguments that conclude his replies to the Second Objections, Descartes lists a number of ‘axioms or common notions’ (CSM ii, 116; see also Principles of Philosophy, Pt I, 49; CSM i, 209). Spinoza also requires for his system certain undefined concepts, which he uses in his definitions, and it may be assumed that these also are included in the ‘common notions’. In speaking of the ‘properties of things’, Spinoza appears to be following traditional usage, according to which a property of X is something that belongs necessarily to X but is not part of its essence.82 More exactly, he seems to have in mind that which follows from the definition of X (and therefore belongs necessarily to X) but is not a part of that definition. So, for example, in Proposition 31 of Part II of the Ethics Spinoza demonstrates that it is a property of any particular thing that it is caused by another, and that by another, and so on ad infinitum. Unlike the imagination, reason grasps the necessary relations between things (Ethics, Pt II, Proposition 44). A corollary of this is that reason perceives things ‘under a certain species of eternity’ (sub quadam aeternitatis specie). What this means can be understood by referring to Definition 8 of Part I of the Ethics, in which Spinoza defines ‘eternity’ as a certain kind of existence—namely, that which follows from the definition of God. The existence in question ‘is conceived as an eternal truth…and therefore cannot be explained by duration or time, even though the duration is conceived as wanting beginning and end’ (ibid.). Eternity, then, has no relation to time; ‘in eternity there is no when, before and after’.83 As applied to reason, this means that to know things by the second kind of knowledge is not simply to say ‘This happened, then that happened’; the relations that are grasped are timeless, logical relations. Reason has another important feature. The bases of reason, Spinoza says, ‘explain the essence of no particular thing’ (Corollary 2 of Proposition 44 of Ethics, Pt II). This must mean that common notions and adequate ideas of the properties of things do not enable us to explain (say) the essence of this particular angry man, but only of anger in general. The same point is made later in the Ethics when Spinoza says (Pt V, Scholium to Proposition 36) that knowledge of the second kind is ‘universal’. On the basis of this one can say that when Spinoza, in the Ethics, provides us with general propositions which are deduced from definitions and self-evident truths, he is providing us with examples of the second kind of knowledge, reason. The universality of the second kind of knowledge is important in that it is this which distinguishes the second from the third kind of knowledge, which (ibid.) is a ‘knowledge of particular things’. With the third kind of knowledge, ‘intuitive knowledge’, we enter upon one of the most obscure and controversial regions of Spinoza’s philosophy. Some interpreters see this kind of knowledge as a kind of mystical vision of the whole; others think that a more prosaic account is called for. Here, I will state a number of features of intuitive knowledge which are not controversial, and which any interpretation must take into account; I will then suggest an interpretation which relates this kind of knowledge both to Descartes’s views about knowledge and to Spinoza’s moral philosophy. Four features can safely be ascribed to intuitive knowledge. 1 Like reason, it is necessarily true;84 that is, the truths known by such knowledge are necessary truths. 2 Like reason, intuitive knowledge conceives and understands things ‘under a species of eternity’.85 3 Unlike reason, intuitive knowledge is (as has just been pointed out) knowledge of particular things.86 4 Unlike reason, again, intuitive knowledge is, as its name suggests, ‘intuitive’. It is this last feature of intuitive knowledge which causes most difficulty. The difficulty arises out of a passage in the second Scholium to Proposition 40 of Part II of the Ethics, in which Spinoza illustrates all three kinds of knowledge by a single mathematical example.87 He takes the problem of finding a fourth proportional. One is given three numbers, and one is required to find a fourth number which is to the third as the first is to the second. Spinoza points out that, in this case, there is a well-known rule: multiply the second number by the third and divide the product by the first. The use of this rule, however, raises two questions. First, on what grounds is the rule accepted? And second, is the use of such a rule always requisite if the problem is to be solved? With regard to the first question, Spinoza points out that some people may have found the rule to work for small numbers, and generalize it to cover all numbers. This would be a case of inductive reasoning, and belongs to the first kind of knowledge, imagination. Others may accept the rule because they know the proof given in Euclid VII, 19. This is based on what Spinoza calls a ‘common property’ of proportionals, and belongs to the second kind of knowledge, reason. But when the numbers involved are small numbers—say, 1, 2 and 3—there is no need to make use of a rule. In such a case, Spinoza says, everyone sees that the fourth proportional is 6; this is because ‘we infer the fourth number from the very ratio which, with one intuition, we see the first bears to the second’. Or, as Spinoza says in the Tractatus de Intellectus Emendatione (G ii, 12), we see the ‘adequate proportionality’ of the numbers ‘intuitively, without performing any operation’. To see things in this way is to make use of the third kind of knowledge, ‘intuitive knowledge’. The problem is that what Spinoza says about the third kind of knowledge appears to be self-contradictory. On the one hand, he seems to hold the view that intuitive knowledge is immediate, in the sense that no process of inference, no application of a general rule to a particular instance, is involved. Yet when he describes intuitive knowledge in the Ethics he speaks of inferring a fourth number. However, it may be that one can get some help here from Descartes. Although Spinoza does not refer to Descartes in the context of the third kind of knowledge, what he says about such knowledge can be illuminated by comparing it with what Descartes says about his famous utterance, Cogito, ergo sum. It is well known that Descartes denied that, in saying ‘I am thinking, therefore I exist’, he was deriving existence from thought by a kind of syllogism. (‘Everything that thinks, exists; I am a being that thinks; therefore…etc.’) (Reply to Second Objections, CSM ii, 100). Rather, he said that he recognized his existence ‘as something self-evident by a simple intuition of the mind’ (ibid.). This may seem to involve him in a difficulty which is similar to Spinoza’s: namely, that Descartes expresses this ‘simple intuition’ in what appears to be the form of an inference, in that it involves the term ‘therefore’. What is of great interest here is the solution that Descartes offered in his conversation of 1648 with the young Dutch scholar Frans Burman.88 Burman had asked about the nature of Cogito, ergo sum; in his reply, Descartes said that the universal proposition ‘Everything that thinks, exists’ is logically prior to ‘I am thinking, therefore I exist’, but that I do not need to know the former proposition before I can recognize the truth of the latter. He went on to say, ‘We do not separate out these general propositions from the particular instances; rather, it is in the particular instances that we think them’. Now, it is not suggested here that Spinoza knew of Descartes’s conversation with Burman,89 or indeed that he would have regarded Cogito, ergo sum as an instance of the third kind of knowledge. The point is simply that we can make sense of what he says about intuitive knowledge by supposing him to be thinking along lines similar to those followed by Descartes. That is, when Spinoza says that, in order to discover a fourth proportional, we do not have to appeal to a universal rule but can make use of intuitive knowledge, what he means can be put in Descartes’s terms by saying that we think of the general rule in the particular instance. The question now arises whether the Ethics contains any substantive examples of the third kind of knowledge, or whether it, at best, only points the way towards such knowledge. There is of course the case of the discovery of a fourth proportional; but this is merely illustrative, and does not play an essential part in the structure of the work. However, there does seem to be an important use of intuitive knowledge in the Ethics. This is to be found in Proposition 36 of Part V, together with its Corollary and Scholium. In the Scholium, Spinoza remarks that, from what he has said elsewhere in the work, ‘It is quite clear to us how and in what way our mind follows with regard to essence and existence from the divine nature and continually depends on God’, and he continues by saying that this is an example of the third kind of knowledge. The Scholium does more than give an example of the third kind of knowledge; it also shows precisely how this kind of knowledge differs from the second, and why Spinoza ascribes such importance to it. Spinoza says (ibid.) that, in the first part of the Ethics, he has already shown90 that ‘all things (and consequently the human mind) depend on God with regard to essence and existence’. This, he says, is an example of the second kind of knowledge; what is more, the proof of this proposition is ‘perfectly legitimate and placed beyond the reach of doubt’. We have, then, no reason to suppose that Spinoza thinks that propositions known by the second kind of knowledge are in any respect less true than those known by the third kind. Rather, the superiority of intuitive knowledge lies in the fact that (ibid.) it is ‘more powerful’ than reason, affecting the mind in a different way. And it is more powerful precisely because it is not universal knowledge, but is the knowledge of particular things. Spinoza’s explanation of the way in which intuitive knowledge is more powerful involves the difficult propositions (beginning in Proposition 32 of Part V of the Ethics) in which he expounds his doctrine of the intellectual love of God. This cannot be discussed here;91 however, one can perhaps get some idea of what is meant by the greater power of intuitive knowledge by considering a hypothetical case. Consider a man who is convinced by Spinoza’s proof (in Proposition 45 of Part IV of the Ethics) of the universal proposition that hatred can never be good. Despite his acceptance of the truth of this universal proposition, such a man may still hate some particular individual who has injured him. Now contrast such a man with another who has intuitive knowledge of the proposition in question, that is, who grasps it in the particular instance of a person who has offended him. The latter kind of knowledge may be called more powerful in that (as Spinoza would say) it affects his mind in a different way, taking away his urge to hurt the offender in question. This, it must be stressed, is only a hypothetical case, offered as a means of throwing light on what Spinoza says. But what can be said without hesitation is that Spinoza’s theory of knowledge was not intended to be purely a contribution to epistemology, but has to be seen in an ethical context. ABBREVIATIONS The following abbreviations are used in Chapters 8 and 9. Spinoza’s works DPP Renati des Cartes Principiorum Philosophiae, Parts I and II E Ethica, ordine geometrico demonstrata. In referring to the contents of the Ethics, ‘P’ is used for ‘Proposition’ and ‘S’ for ‘Scholium’. So, for example, E II P40S2 refers to Ethics, Part II, Proposition 40, Scholium 2. ‘Ax’ is used for ‘Axiom’, ‘C’ for ‘Corollary’, ‘D’ for ‘Definition’ and ‘L’ for ‘Lemma’ Ep Epistolae G C.Gebhardt (ed.), Spinoza, Opera (cf. [8.1]); references are to volume and page KV Korte Verhandeling van God, de Mensch en deszelfs Welstand TDIE Tractatus de Intellectus Emendatione TP Tractatus Politicus TTP Tractatus Theologico-Politicus Other works CSM J.Cottingham, R.Stoothoff and D.Murdoch (eds.) The Philosophical Writings of Descartes (Cambridge, Cambridge University Press, 3 vols, 1985, 1991). NOTES 1 Nicolaus Steno (the Danish scientist Niels Stensen). The phrase occurs in an open letter published by Stensen in 1675; the original letter had been written four years previously. (See M.Walther (ed.) Baruch de Spinoza: Briefwechsel (Hamburg, Meiner, 1977), p. 410.) The text is published as No. 67a of Spinoza’s correspondence (G iv, 292–8). 2 Wolf son [8.43], vol. I, p. vii. 3 For a brief survey of the dispute, see H.G.Hubbeling, Spinoza (Freiburg/ Münich, Alber, 1978), pp. 81–2. 4 For this and other valuable information about Spinoza’s youth, see A.M.Vaz Dias and W.G.van der Tak, Spinoza, Mercator et Autodidactus (The Hague, Nijhoff, 1932), pp. 56ff. 5 For the circumstances of this excommunication, and in particular the relation between Spinoza and Dr Juan de Prado, see C.Gebhardt, ‘Juan de Prado’, Chronicon Spinozanum 3 (1923) 269–91; Révah [8.23]; Révah [8.24]; Yirmiyahu Yovel, Spinoza and other Heretics (Princeton, N.J., Princeton University Press, 1989), vol. I, The Marrano of Reason, pp. 57–83. 6 Thijssen-Schoute [8.27], 210. 7 Révah [8.23], 43. On the libertins, see A.Adam, Les libertins an 17e siècle (Paris, Buchet/Chastel, 1964: a selection of texts), and Popkin [8.22], 87–109. 8 Jarig Jelles, Preface to Spinoza’s Posthumous Works. See C.Gebhardt, Spinoza: Lebensbeschreibungen und Gespräche (Leipzig, Meiner, 1914), p. 3. On the Mennonite Jelles, cf. Siebrand [8.26], 25, 35–49. 9 Révah [8.23], 31–2, 36. 10 See Ep 6 (G iv, 36); also Joachim [8.45], 5–7, 14–15. 11 A useful summary of scholarly discussions of this work may be found in Curley [8. 4], 46–53. 12 KV I, 3. 13 Cogitata Metaphysica, II, 12 (G i, 279); cf. Gueroult [8.55], 245n. 14 KV I, 8–9; E I P29S; cf. Gueroult [8.55], 564, and note 71 below. 15 It is hardly necessary to add that Descartes, too, sometimes used scholastic terminology. On Spinoza’s use of the works of Heereboord, see H.de Dijn, ‘Historical Remarks on Spinoza’s Theory of Definition’, in J.G.van der Bend (ed.) Spinoza on Knowing, Being and Freedom (Assen, Van Gorcum, 1974), pp. 41–50. 16 Ep 13 (G iv, 63). 17 For details, see Parkinson [8.47], 6 n3. 18 B.d.S. Opera Posthuma and De Nagelate Schriften van B.d.S. Both must be based on manuscript sources, and so the Dutch version can be used as a check on the Latin text. It has been argued by Gebhardt (G ii, 341–3) that the Dutch version of the first two parts of the Ethics was based on an early text which Spinoza abandoned in 1665 when he turned aside to work on the Tractatus Theologico- Politicus, but this view has been called in question (F.Akkerman, ‘L’édition de Gebhardt de l’Ethique et ses sources’, Raison présente 43 (1977) 43). 19 This includes a recently discovered letter to Meyer of 26 July 1663. For this letter, see S.Hessing (ed.) Speculum Spinozanum (London, Routledge, 1977), pp. 426–35. 20 Ep 6, 7, 11, 13, 14, 16, 25–6, 29–33, 36, 38–41, 46. 21 See J.Freudenthal, Die Lebensgeschichte Spinozas (Leipzig, Veit, 1899), pp. 160–4. The list is perhaps more readily accessible in Préposiet [8.16], 339–43. 22 The mathematical works include books by Euclid, Diophantus, Descartes and Viète. Works on astronomy include ‘The Sphere’ (Sphaera) by Johannes de Sacrobosco (John of Holywood), a thirteenth-century writer whose account of the heavens was still widely used in the sixteenth and seventeenth centuries, and a book by Christian Longomontanus, a Danish astronomer who had been Tycho Brahe’s assistant. The works on physics in Spinoza’s library included books by Descartes, Huygens, James Gregory, Robert Boyle and Niels Stensen. Spinoza also owned a number of books on anatomy, including Descartes’s De Homine and works by Stensen and by the Dutch physician Nicolaes Tulp. 23 See the Preface to the Opera Posthuma (Gebhardt, Spinoza: Lebensbeschreibungen und Gespräche, p. 7); also Ep 60, January 1675, and Ep 83, 15 July 1676. 24 All translations from Spinoza in this chapter are my own, with the exception of the translation of the Ethics, where Boyle [8.9] is used. 25 A Treatise of Human Nature, Book III, Pt 1, sec. 1. 26 E III Pref. (G ii, 137). 27 ‘Man as a Subject for Science’, in Ayer, Metaphysics and Common Sense (London, Macmillan, 1969), p. 219. 28 See Chapter 5, pp. 183–6. The distinction was known to Spinoza; it is mentioned by Meyer, in his Preface to Spinoza’s geometrical version of Descartes’s Principles of Philosophy (G i, 129). 29 Collection, beginning of Book VII. I translate from the Latin version by the Renaissance mathematician Federico Commendino (Venice, 1589), which Descartes used. (cf. E.Gilson, René Descartes, Discours de la Méthode (Paris, Vrin, 1947), p. 188.) On the concept of analysis in Pappus, see also H.-J.Engfer, Philosophie als Analysis (Stuttgart, Frommann-Holzboog, 1982), pp. 78–89. 30 In the case of Spinoza’s geometrical version of the Principles of Descartes, where not all the derived propositions are held by Spinoza to be true (cf. p. 276 above), it may be assumed that Spinoza would say that some of the axioms are false. 31 I have discussed this topic at greater length in my paper ‘Definition, Essence and Understanding in Spinoza’, in J.A.Cover and Mark Kulstad (eds) Central Themes in Early Modern Philosophy: Essays presented to Jonathan Bennett (Indianapolis, Ind., Hackett, 1990), pp. 49–67. 32 I.M.Copi, Introduction to Logic (New York, Macmillan, 3rd edn, 1968), p. 98. 33 E III, Definitions of the Emotions, No. 20 (G ii, 195); cf. Parkinson, in Cover and Kulstad, op. cit., pp. 52–4. 34 In his Introduction to Logic, p. 101, Copi calls such definitions ‘theoretical definitions’ and points out how, in the course of the history of science, ‘one definition is replaced by another as our knowledge and theoretical understanding increase’. 35 The major premise is ‘All bodies near the earth are bodies that shine steadily’, the minor premise is ‘All planets are bodies near the earth’, giving the conclusion ‘All planets are bodies that shine steadily’. 36 Descartes, Discourse on Method, Part II (CSM i, 119); Regulae, No. 10 (CSM i, 37). 37 Spinoza’s formal definition of the essence of a thing in E II D2 is much more complex. I have discussed it in Cover and Kulstad, op. cit., pp. 58–62. 38 See, for example, John Marenbon, Early Medieval Philosophy (London, Routledge, 1983), pp. 98–101. 39 For Leibniz’s views about the ontological argument, cf. G.H.R.Parkinson, Logic and Reality in Leibniz’s Metaphysics (Oxford, Clarendon, 1965; reprinted, New York, Garland, 1985), pp. 77–85. 40 Hume, Treatise of Human Nature, Book I, Pt 3, sec. 2; Kant, Critique of Pure Reason, B 247–8. 41 The rationalist theory of causality is also implicit in E I P16 and its three corollaries, where Spinoza begins (E I P16) by speaking of certain things as ‘necessarily following from’ the divine nature, and then goes on to describe the various ways in which God is a cause. 42 An Abstract of a Treatise of Human Nature: see Hume, An Enquiry concerning Human Understanding, ed. A.G.N.Flew (La Salle, Ill., Open Court, 1988), p. 34; cf. A Treatise of Human Nature, Book I, Pt 3, sec. 3. 43 There is indeed no evidence that Hume had read Spinoza at all; his views about Spinoza appear to be derived from a well-known article in Bayle’s Dictionary (cf. A Treatise of Human Nature, Book I, Pt 4, sec. 5). Of this dictionary, Flew says (op. cit., p. 186, n. 121) that it was, in some version or other, ‘in every gentleman’s library throughout the eighteenth century’. 44 cf. Nicholas Jolley, Chapter 11 of this volume, pp. 385–6. 45 This is not to say that Spinoza ignores the second problem, but his answer to it involves, not his concept of substance, but his concept of an ‘individual’. See p. 288. 46 Though Spinoza’s assertion that a substance must be conceived through itself could hardly be accepted by Aristotle. For Aristotle (though not for Spinoza) Socrates would be a substance; but Aristotle would say that Socrates is not ‘conceived through himself, in that Socrates has to be conceived through various genera and species. 47 The argument appears to rest on E I P8 and E I P11. E I P8 says in effect that, if there is a substance, then it is infinite; E I P11 asserts that there is such a substance —namely, God. 48 The reference to ‘created’ thinking substance serves to distinguish minds such as ours from the mind of God, the uncreated substance. 49 E I P10S, P11, P16, P19, P29S. 50 For a very thorough survey of the issue, see F.S.Haserot, ‘Spinoza’s definition of attribute’, in Kashap [8.36], 28–42. 51 Though there is a hint of this in E I P14C2. 52 Spinoza regards these as two out of an infinity of attributes, the rest of which are, and indeed must be, unknown to us. Some scholars have argued that he regarded thought and extension as the only attributes, and that in calling them ‘infinite’ he meant that they are all the attributes that exist. (See A.Wolf, ‘Spinoza’s Conception of the Attributes of Substance’, in Kashap [8.36], 24–7.) But this is hard to reconcile with the textual evidence: see especially E II P7S and Ep 64. 53 Principles of Philosophy, I, 60 (CSM i, 213). 54 E I P10. 55 E I P13 and C3; cf. E I P15S. 56 E I P25C. 57 E I P21. This is explained in Ep 64. 58 Incidentally, Spinoza had the greatest respect for the atomists among the classical Greek philosophers (Ep 56). 59 Ep 32 (G iv, 173); cf. DPP II P13. 60 For a contrary view, see Donagan [8.31], 68. 61 See especially the synopsis of Meditation II, CSM ii, 110: ‘secondly we need…’. 62 E.g. E II P9. 63 See especially E II P49 and S. 64 E II P49C and S. For a discussion of Spinoza’s criticism of Descartes’s theory of judgement, see J.G.Cottingham, ‘The Intellect, the Will and the Passions: Spinoza’s Critique of Descartes’, Journal of the History of Philosophy 26 (1988) 239–57. 65 E II P43S: ‘And again how can anyone…’. 66 E III P2S (G ii, 142–3). 67 Perhaps an echo of the title of Vesalius’s famous treatise on anatomy, De Humani Corporis Fabrica (1543). 68 On which see Chapter 11 (pp. 404–7). 69 cf. G.N.A.Vesey, ‘Agent and Spectator’, in G.N.A.Vesey (ed.), The Human Agent, Royal Institute of Philosophy Lectures, vol. 1 (1966–7) (London, Macmillan, 1968), pp. 139–40. Spinoza’s theory could also be regarded as belonging to what D.M.Armstrong calls ‘attribute’ or ‘dual-attribute’ theories of the mind-body relationship. See Armstrong, ‘Mind-Body Problem: Philosophical Theories’, in R.L.Gregory (ed.), The Oxford Companion to the Mind (Oxford, Oxford University Press, 1987), p. 491. 70 E I P16 and C1. 71 In explaining the immanent causality of God, Spinoza makes use of a distinction that has since achieved some fame. This is the distinction (E I P29S) between ‘natura naturans’ and ‘natura naturata’, which may be rendered as ‘active nature’ and ‘passive nature’. By ‘active nature’ Spinoza means substance or its attributes, that is, God conceived as the ultimate explanation of everything; by ‘passive nature’ he means the totality of modes, conceived not as so many isolated entities, but as following from, that is, as the effects of, God. By calling both God and his effects types of ‘nature’, Spinoza makes the point that God is not outside his effects. 72 In E I P11S, Spinoza hints that by ‘perfection’ he means ‘reality’; this is confirmed by the formal definition of perfection in E II D6. In traditional language, Spinoza’s God is the ens realissimum, that whose being is the most rich. (cf. E I P9: the more reality a thing has, the more attributes belong to it.) 73 cf., for example, E III P7. 74 E I P32C1, E I P33 and 33S1. 75 E I A6, E II D4. 76 cf. J.J.McIntosh, ‘Spinoza’s Epistemological Views’, in G.N.A.Vesey (ed.) Reason and Reality, Royal Institute of Philosophy Lectures, vol. 5 (1970–1) (London, Macmillan, 1972), p. 38; also G.H.R.Parkinson, ‘“Truth is its Own Standard”. Aspects of Spinoza’s Theory of Truth’, in Shahan and Biro [8.40], 42–5. 77 In the Tractatus de Intellectus Emendatione (G ii, 10–12), Spinoza recognizes four kinds of knowledge, the first two of which correspond to the first of the three kinds recognized in the Ethics. The Short Treatise recognizes three kinds only, but the account that it offers of these is sketchy. 78 Spinoza also counts as an example of the first kind of knowledge what he calls ‘knowledge from signs’ (E II P40S2; cf. E II P18S). This raises interesting questions concerning Spinoza’s views about language, which I have discussed in my ‘Language and Knowledge in Spinoza’, reprinted in Grene [8.33], 73–100. 79 It is not clear how Spinoza would have attempted to justify his view that induction is a kind of knowledge. 80 E II P38–9, P40 and S2; cf. E V P36S. 81 This is in fact a literal translation of the Greek term ‘koinai ennoai’, used by Euclid to refer to the axioms of his system. 82 cf. Aristotle, Topics, I 5, 102 a18–19. On ‘essence’ in Spinoza, cf. p. 282. 83 E I P33S2. 84 E II P41. 85 E V P31 and S. 86 E V P36S. 87 See also TDIE, G ii, 12, and KV II.1, G i, 54–5. 88 For this conversation, see Descartes’ Conversation with Burman, ed. and trans. J.G.Cottingham (Oxford, Clarendon, 1976), esp. p. 4 (also CSM iii, 333). 89 Burman’s record of the conversation remained in manuscript until 1896. In principle, Spinoza could have had access to the manuscript, but there is no evidence that he had any contact with Burman, or with the Cartesian philosopher Clauberg, who also contributed to the manuscript. 90 The reference is probably to E I P15, mentioned in E V P36S. It could perhaps be to E I P25, but this itself involves a reference to E I P15. 91 This doctrine, and the related doctrine of the eternity of the human mind, has been severely criticized. See, for example, Bennett [8.28], 357–63, 369–75; Delahunty [8.30], 279–305; Martha Kneale, ‘Eternity and Sempiternity’, in Grene [8.33], 227– 40. A more sympathetic account is given by Joachim [8.35], 230–3, 298–309. BIBLIOGRAPHY Original language editions 8.1 Gebhardt, C. (ed.) Spinoza, Opera, Heidelberg, Winter, 4 vols, 1924–8. 8.2 van Vloten, J. and Land, J.P.N. (eds) Benedicti de Spinoza Opera quotquot reperta sunt, The Hague, Nijhoff, 1st edn, 2 vols, 1882–3; 2nd edn, 3 vols, 1895; 3rd edn, 4 vols, 1914. English translations Complete and selected works 8.3 The Chief Works of Benedict de Spinoza, trans. R.H.M.Elwes, London, Bell, 2 vols, 1883–4; reprinted, New York, Dover Publications, 1955. 8.4 The Collected Works of Spinoza, trans. E.Curley, Princeton, N.J., Princeton University Press, vol. 1, 1985. 8.5 The Ethics and Selected Letters, trans. S.Shirley, Indianapolis, Ind., Hackett, 1982. 8.6 Spinoza, the Political Works. The Tractatus theologico-politicus in part and the Tractatus politicus in full, trans. A.G.Wernham, Oxford, Clarendon, 1958. Separate works 8.7 The Correspondence of Spinoza, trans. A.Wolf, London, Allen & Unwin, 1928. 8.8 Ethic: from the Latin of Benedict de Spinoza, trans. W.Hale White and Amelia Stirling, London, Fisher Unwin, 1894. 8.9 Ethics, trans. A.Boyle, revised G.H.R.Parkinson, London, Dent, 1989. 8.10 On the Improvement of the Understanding, trans. J.Katz, New York, Liberal Arts Press, 1958. 8.11 The Principles of Descartes’ Philosophy, trans. H.H.Britan, La Salle, Ill., Open Court, 1905. 8.12 Spinoza’s Short Treatise on God, Man and his Well-being, trans. A.Wolf, London, Black, 1910. 8.13 Tractatus Theologico-Politicus, trans. S.Shirley, Leiden, Brill, 1989. Bibliographies and concordances Bibliographies 8.14 Boucher, W.I. Spinoza in English: A Bibliography from the Seventeenth Century to the Present, Leiden, Brill, 1991. 8.15 Oko, A.S. The Spinoza Bibliography, Boston, Mass., Hall, 1964. (An exhaustive bibliography of Spinoza literature up to 1940.) 8.16 Préposiet, J. Bibliographie spinoziste, Paris, Les Belles Lettres, 1973. 8.17 van der Werf, T. A Spinoza Bibliography, 1971–83, Leiden, Brill, 1984. 8.18 Wetlesen, J. A Spinoza Bibliography, 1940–70, Oslo, Universitetsvorlaget, 1971. Concordances 8.19 Boscherini, E.G. Lexicon Spinozanum, The Hague, Nijhoff, 2 vols, 1970. 8.20 Gueret, M., Robinet, A. and Tombeur, P. Spinoza, Ethica. Concordances, Index, Listes de fréquences, Tables comparatives, Louvain-la-Neuve, CETEDOC, 1977. Influences on Spinoza 8.21 Gebhardt, C. ‘Spinoza und der Platonismus’, Chronicon Spinozanum 1 (1921) 178–259. (Spinoza and Leone Ebreo.) 8.22 Popkin, R.H. ‘Spinoza and La Peyrère’, in R.W.Shahan and J.I.Biro (eds) Spinoza: New Perspectives, Norman, Okl., University of Oklahoma Press, 1978, 177–96– 8.23 Révah, I.S. Spinoza et le Dr. Juan de Prado, Paris, Mouton, 1959. 8.24 Révah, I.S. ‘Aux origines de la rupture spinozienne’, Revue des études juives 3 (1964) 359–431. 8.25 Roth, L. Spinoza, Descartes and Maimonides, Oxford, Clarendon, 1924. 8.26 Siebrand, H.J. Spinoza and the Netherlanders, Assen, Van Gorcum, 1988. 8.27 Thijssen-Schoute, C.L. ‘Le Cartésianisme aux Pays Bas’, in E.J.Dijksterhuis (ed.) Descartes et le Cartésianisme hollandais, Paris, Presses Universitaires de France, 1950. The philosophy of Spinoza: general surveys 8.28 Bennett, J. A Study of Spinoza’s Ethics, Cambridge, Cambridge University Press, 1984. 8.29 Brunschvicg, L. Spinoza et ses contemporains, Paris, Presses Universitaires de France, 1923. 8.30 Delahunty, R.J. Spinoza, London, Routledge & Kegan Paul, 1985. 8.31 Donagan, A. Spinoza, London, Harvester, 1988. 8.32 Freeman, E. and Mandelbaum, M. (eds) Spinoza: Essays in Interpretation, La Salle, Ill., Open Court, 1975. 8.33 Grene, M. (ed.) Spinoza: A Collection of Critical Essays, New York, Doubleday, 1973. 8.34 Hampshire, S.N. Spinoza, Harmondsworth, Penguin, 1951. 8.35 Joachim, H.H. A Study of the Ethics of Spinoza, Oxford, Clarendon, 1901. 8.36 Kashap, S.P. (ed.) Studies in Spinoza, Berkeley, Calif., University of California Press, 1972. 8.37 Kennington, R. (ed.) The Philosophy of Baruch Spinoza, Washington, D.C., Catholic University of America, 1980. 8.38 Pollock, F. Spinoza, His Life and Philosophy, London, Kegan Paul, 1880. 8.39 Scruton, R. 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Spinoza: A Collection of Critical Essays, New York, Doubleday, 1973, 73–100. 8.49 Savan, D. ‘Spinoza and Language’, Philosophical Review 67 (1958) 212–25. Also in S.P.Kashap (ed.) Studies in Spinoza, Berkeley, Calif., University of California Press, 1972, 236–48. 8.50 Walker, R.C.S. ‘Spinoza and the Coherence Theory of Truth’, Mind 94 (1985) 1–18. Metaphysics and philosophy of mind 8.51 Barker, H. ‘Notes on the Second Part of Spinoza’s Ethics’, Mind 47 (1938) 159–79, 281–302, 417–39. Also in S.P.Kashap (ed.) Studies in Spinoza, Berkeley, Calif., University of California Press, 1972, 101–67. 8.52 Curley, E. Spinoza’s Metaphysics, Cambridge, Mass., Harvard University Press, 1969. 8.53 Deleuze, G. Spinoza et le problème de l’expression, Paris, Editions de Minuit, 1968. 8.54 Donagan, A. ‘Essence and the Distinction of Attributes in Spinoza’s Metaphysics’, in M.Grene (ed.) Spinoza: A Collection of Critical Essays, New York, Doubleday, 1973, 164–81. 8.55 Gueroult, M. Spinoza: Dieu (Ethique, 1), Paris, Aubier, 1968. 8.56 Gueroult, M. Spinoza: L’Ame (Ethique, 2), Paris, Aubier, 1974. 8.57 Haserot, F.S. ‘Spinoza’s Definition of Attribute’, Philosophical Review 62 (1953) 499–513. Also in S.P.Kashap (ed.) Studies in Spinoza, Berkeley, Calif., University of California Press, 1972, 28–42. 8.58 Kneale, M. ‘Eternity and Sempiternity’, Proceedings of the Aristotelian Society 69 (1968–9) 223–38. Also in M.Grene (ed.) Spinoza: A Collection of Critical Essays, New York, Doubleday, 1973, 227–40. 8.59 Parkinson, G.H.R. ‘Spinoza on Miracles and Natural Law’, Revue internationale de philosophie 31 (1977) 145–57. 8.60 Parkinson, G.H.R. ‘Spinoza’s Philosophy of Mind’, in G.Fløistad (ed.) Contemporary Philosophy: A New Survey, The Hague, Nijhoff, 1983, vol. 4, 105–31. 8.61 Robinson, L. Kommentar zu Spinozas Ethik, vol. 1, Leipzig, Meiner, 1928. (Covers the first two parts of the Ethics.) 8.62 Sprigge, T.L.S. ‘Spinoza’s Identity Theory’, Inquiry 20 (1977) 419–45. 8.63 Wolf, A. ‘Spinoza’s Conception of the Attributes of Substance’, Proceedings of the Aristotelian Society 27 (1927) 177–92. Also in S.P.Kashap (ed.) Studies in Spinoza, Berkeley, Calif., University of California Press, 1972, 16–27.

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