Supposed process of forming an idea by abstracting out what is common to a variety of instances: a process stressed, for example, by Aquinas in his moderate solution to the problem of universals (abstrahentium non est mendacium : abstraction is not lying). The problem is that unrestricted abstraction leads one to suppose that qualities such as substance, causation, change, and number may apply not only to the sensible bodies that give rise to our ideas of them, but also in a spiritual realm or other domain quite outside the reach of experience. Locke is vehemently attacked by Berkeley for this and related errors. See also abstract ideas.
Philosophy dictionary. Academic. 2011.