The Epistemology of Abstraction

Abstract

The notion of abstraction or separation is most evidently found in Aristotle in the application of mathematical principles, as, e.g., when quantities are taken or separated off from extended objects to determine the area of plot of land in square meters or yards through a practical application of geometry. In epistemology in the medieval traditions intellectual abstraction involved the view that human knowing comes about through an apprehension of the forms of things of the world by separating or abstracting the intelligible in some sense from the formal contents of things having physical form and matter. Not just a simple issue of selective attention, this was taken to be a metaphysical process in which a special power available to human beings is understood to make possible the separation of the intelligible form or essence of a thing from its reality in the nature of a material entity and the realization of that form in the human intellect. While not altogether unrelated, this is not to be confused with the Platonic methodology of positing a one to exist over the many in the case of a sensory apprehension of a plurality of particulars found in Republic V (507b) which asserted there to be separately existing Forms as the essences of imperfect particular forms in things of physical reality or the realm of opinion. Rather, in intellectual abstraction the intelligible form of the thing experienced in nature in some way prompts a transference or movement of some sort whereby the human knower employs sensory experience of particulars and the power of intellect to grasp the form as intelligible through an act of the human intellect. Though not found in an explicit way in the philosophical psychology of Aristotle(pace Gutas 2012: 426 ff.; cf. Burnyeat 2008), there are texts which seem to permit an abstractionist account (e.g. De Anima 3.5, and 3.4, 3.7, 3.8; Cleary 1985). Nevertheless, it was only many centuries after Aristotle (d. fifth century B.C.E.) that the doctrine of intellectual abstraction for the formation of intelligibles in act by the human rational soul or intellect was first unambiguously set forth by Alexander of Aphrodisias (second century C.E.). His work was important for Porphyry and influential in both the Latin and the Arabic philosophical traditions (Tweedale 1984). In Alexander’s On theIntellect which was very important in Ish. a-q Ibn H. unayn’s Arabic translation (Finnegan in Alexander of Aphrodisias 1956) we find the following:[E]nmattered forms are made intelligible by the intellect, being intelligible potentially. The intellect separates them (cho-rizo-n/yufridu-ha-) from the matter with which they have their being, and itself makes them intelligible in actuality, and each of them, when it is thought, then comes to be intelligible in actuality and intellect; [but] they are not like this previously or by their own nature.