1 Historically, the contrast is between chaos, or the unordered, unformed, undifferentiated beginnings of things, and the cosmos, which is the ordered universe (see also logos ). The concept is thus implicit in early Greek cosmogony.
2 In modern science, chaotic systems are ones in which an arbitrarily small difference in the initial conditions can produce arbitrarily large differences in later states. The common example is that the atmosphere may be such that the flapping of a butterfly at a point and a time may determine whether or not there occurs a hurricane at a different point some time later. The possibility of such systems forces a distinction between thinking of a system as deterministic and thinking of it as completely predictable in principle. Chaotic systems can be deterministic, but are not predictable, for however accurate a measurement of the state at a time, a variation smaller than any it can detect may be responsible for a difference in the eventual outcome.
Philosophy dictionary. Academic. 2011.