Long ago I came across a statement by Aristotle, 'True knowledge is identical with its object'. I never came across it again and now wonder where I found it.
Is there an Aristotle scholar here who knows where this statement appears?
It sounds like the following statement, to be found in Aristotle's On the Soul, Book III, Part 7 (Translated by J. A. Smith; p. 1242 in the Aristotle Organon and Other Works, translated under the editorship of W. D. Ross):
Actual knowledge is identical with its object: potential knowledge in the individual is in time prior to actual knowledge but in the universe it has no priority even in time; for all things that come into being arise from what actually is.
Of course I'm no Aristotle scholar but I tracked it down first by googling the phrase given in the question and finding it first here, thereafter searching Internet Archive for a slightly more original text.
I personally like my own peculiar way of saying it:
And Aristotle is also quoted as saying something similar, in Aristotle de Anima (R. D. Hicks):
It is possible to have hearing and yet not hear; again, that which is resonant is not always sounding. But when that which is capable of hearing actually hears and that which is capable of sounding sounds, the actual hearing and the actual sound occur simultaneously.
I threw that in because the question immediately caused me to think of it, and the idea is very important to me personally because that is how I believe humans are capable of truly knowing God: through identification (what I call "resonance") with it.