The perceptual capacity is in potentiality such as the perceptible object already is in actuality; it is affected as unlike, but by being affected it becomes like its object—this likeness-in-actuality concluding his account of perception as the reception of form without matter.

By Aristotle, from On the Soul

Key Arguments

  • He states his key hylomorphic thesis about perception in this context: 'What can perceive is potentially such as the perceptible object already is actually, as has been said.'
  • He then gives his concise account of perceptual affection: 'It is affected, then, as being not like the object, but when it has been affected it is made like it, | 418'
  • This restates, at the end of the chapter, his earlier doctrine that perception is a special kind of alteration in which the sense-organ, initially unlike the object in its state, becomes like the object with respect to its sensible form.
  • It also ties back to his earlier reconciliation that 'in one way like is affected by like and in another by unlike'—here specifying that the organ is initially unlike and becomes like through being affected.

Source Quotes

227 But since there is no name for the difference (diaphora) between these, although it has been determined | 418 a 1 | about them that they are distinct and in what way they are distinct, we must go on using “being affected” and “being altered” as if these names had their prevalent meaning. 228 What can perceive is potentially such as the perceptible object already is actually, as has been said. It is affected, then, as being not like the object, but when it has been affected it is made like it, | 418
228 What can perceive is potentially such as the perceptible object already is actually, as has been said. It is affected, then, as being not like the object, but when it has been affected it is made like it, | 418

Key Concepts

  • What can perceive is potentially such as the perceptible object already is actually, as has been said.
  • It is affected, then, as being not like the object, but when it has been affected it is made like it, | 418

Context

Final lines of the excerpt from II.5 (418a1–end of the given text), where Aristotle crystallizes his earlier discussion of potentiality, affection, and likeness into a concise hylomorphic formulation of perception as the becoming-like of a potential organ to an actual perceptible.