Descartes: a cautious revolutionary

In his Meditations on First Philosophy Descartes continues the work he’d begun in his Discourse on the Method, trying to overturn Aristotelian metaphysics, which was still the predominant way of thinking about philosophy at his time. It becomes clear that he wishes to remove the veil Aristotle had placed over knowledge by classifying sciences according to their content. What Descartes was looking for was a method, some kind of methodological unity, and he believed that logic could provide this ubi consistam for the sciences.

“…I was convinced of the necessity of undertaking once in my life to rid myself of all the opinions I had adopted, and of commencing anew the work of building from the foundation, if I desired to establish a firm and abiding superstructure in the sciences.”

It goes without saying that this was a big deal at the time: Aristotelian works were still the main reference work and were used in universities as textbooks. This is the reason why Descartes is considered to have taken part in the “Copernican revolution” -in a metaphorical sense- but also why he’s very cautious in bringing down the Aristotelian system. Actually, it is precisely in this balanced attitude that he seems to apply Aristotle’s idea of mesotes, moderation. He tries to avoid extremes; he chooses the middle path. When having to choose between black or white, he always chooses grey, since even if black is right then he isn’t totally wrong. However, even in choosing moderation, Descartes distances himself from the Greek philosopher, since he believes this choice of mesotes is made out of common sense, rather than driven by reason.

It is because of his innovative metaphysics that Descartes is often considered the father of modern philosophy. Calling into question Aristotle’s reasoning and underlining its limits at that time was considered an act of hubris.  Aristotle had been the first to discover the rules of the logic discourse and in doing so he had identified the principles according to which the human logos is universally true. It is here that Descartes finds his limitation: Aristotle gave a qualitative definition of knowledge, based on empirical research and on tracing the four causes, scire per causas. He, instead, believed in a quantitative definition, based on the research for constants and on cause-effect sequences. He was a mathematician after all. This is his “Copernican revolution” in a gnoseological sense: he gets rid of empiricism and establishes a mechanical metaphysics.

However, getting rid of empiricism implies some kind of scepticism. Here again he’s cautious. He looks back at sceptics – if we go back to the sixth/fifth century BC, Parmenides was one of the first to state that in the world of appearances our sensory faculties are deceiving and lead us to misconceptions and false ideas – but his scepticism isn’t absolute, his doubt regarding everything we know is only methodological.

“It is now manifest to me that bodies themselves aren’t properly perceived by the senses nor by the faculty of imagination, but by the intellect alone.”

Sure enough, his doubt is resolved when he finds the correspondence in reality of his thought. With this dualism of thought and reality we finally get to his famous “cogito ergo sum”.  Here is the culmination of his metaphysics, the two substances: the res cogitans and the res extensa.