Leibniz's critiques of Descartes' theory of perception

Abstract

The aim of this paper is to try to answer the critiques made by Leibniz against Descartes’ theory of perception. The first of these critiques concerns the so-called ‘idea-picture’. The answer to this critique will be given on the basis of the Cartesian theory of ‘causal dissimilarity’ between the object of perception and the sensations brought about by it. The second critique refers to the qualia, that is, the supposed disconnection and arbitrariness between the content of the mental representation (the idea) and its material referent. The answer to this critique will be given by means of the psychophysical correlation that Descartes calls ‘institution of nature’. Finally, the last critique relates to the non-sensorial perceptions. In order to answer this critique, it will be showed that Descartes held that matter is infinitely divisible and consequently he defended that there are many portions of bodies whose perception escapes the reach of our senses. These discussions will allow us to conclude that, in what concerns the ‘idea-picture’ and the qualia, Leibniz would have made a mistake in his critique, and as to the non-sensorial perceptions, the German philosopher would have developed a conception of perception which was built on notions put forward in Descartes’ physics.