The phenomenon described as “perceiving that one sees” or “perception of one's own perception” has attracted the attention of many philosophers. In this article, I articulate the differences between Aristotle's and Descartes' understanding of this phenomenon, with brief comments on the discussion of the same phenomenon in the Cyrenaics, Stoics and Plotinus.
In several passages Aristotle explores this phenomenon, i. e. “perceiving that one sees.” We should pay special attention to the fact that in De somno, Aristotle assumes that trans-modal discrimination (such as discrimination of sweet from white) implies this sort of higher order perception. We can explain this implication as follows: when we discriminate, for example, sweet from white, we also discriminate the respective modes of perception, namely, tasting in the perception of sweet on the one hand and seeing in the perception of white on the other. This means that Aristotle understands perceiving that one sees as an integral part of the first order perception of the external thing. This is why this second order recognition is a kind of sense-perception par excellence for Aristotle.
Descartes elucidates the phenomenon of perceiving that one sees in an opposite way from Aristotle. He separates this phenomenon from the external object that one perceives. Descartes restricts the sense-perception within one’s subjective experience and counts it as a mode of thought. This is sense-perception in its proper (praecise) sense for Descartes and what he calls conscientia (consciousness). Descartes broke the Aristotelian unity between our inner activity and its external objects, and the Cartesian concept of consciousness is a historical product of this break. By examining the explanations of the same phenomenon expounded by the Cyrenaics, Stoics and Plotinus, we can confirm its historicity.