”By the end of the 16th century, philosophy had stopped. It was Descartes who started it up again.”
“Cogito ergo sum,” (I think, therefore I am) is the most famous, the most quoted line of philosophy in history. I’m certain that I had heard it by middle school, making Descartes the first philosopher to crack my awareness.
Strathern emphasizes in this introduction just how thoroughly Descartes revolutionized philosophy. Of philosophy practiced before Descartes Strathern writes:
”Scholasticism was the philosophy of the Church and prided itself on its lack of originality. New philosophical ideas resulted only in heresy.”
But the primacy of that long stasis had been shattered by both Renaissance and Reformation, and Descartes became the thinker to first apply new ideas to philosophy. He started by introducing a new method in his treatise Rules for the Direction of the Mind:
”In order to discover the universal science, he argued, we first had to adopt a method of thinking properly. This method consisted of following two rules of mental operation; intuition and deduction. Intuition Descarte defined as the conception without doubt of an unclouded, and attentive mind which is formed by the light of reason alone. Deduction was defined as necessary inference from other facts which are know for certain. And Descartes celebrated method, which came to be known as the Cartesian Method lay in the correct application of these two rules of thought.”
Though Descartes set about writing A Treatise on the Universe, he circumspectly put it aside after observing what the Inquisition had done to Galileo who had covered much of the same material with many of the same conclusions. He would eventually include some of the less controversial parts of this treatise in later work. He was a careful man with no drive to be a martyr.
His most original work, Discourse on Method, cover a lot of ground. It changed the face of mathematics, made revolutionary advances in science, laid the foundations of modern, analytic geometry, and introduce Cartesian Coordinates. In optics, it proposed the Law of Refraction, and suggested an explanation of rainbow. But most important of all was its brief introduction, which would change the course of philosophy. Strathern writes of it:
”In clear, autobiographical prose he describes how he goes about his thinking, and the thoughts that occur to him in the process. When you read Descarte, you experience what it is like to be a great mind thinking original philosophy.”
Strathern, the irreverent, cynical philosopher seems almost romantically smitten by Descartes and his times. Of them he writes:
”Descartes was alive during a brief and possibly unique era of human thought. The new explanations put forward by the finest scientific and philosophical minds of his time were in many cases both plausible and comprehensible. They also tended to be rational, and in their overall conception simple, with the aim of leaving space for the contemplation of ultimate mysteries. Humanity is unlikely to experience such an era again.”
Indeed, Strathern almost entirely abandons the snarky wit that has made this series pop. He does manage a couple small hits, as in the way he introduces the fact that Descartes financed his philosophical work entirely through his significant personal fortune:
”Descartes never did a stroke of useful work in his life.”
And again he takes a little shot when discussing how Descartes published Discourse on Method:
”Having had the courage to doubt the entire universe, Descartes typically chose to publish his work anonymously.”
But apart from these minor snarks, Strathern seemed too impressed with Descartes to attempt his usual, witty demystifications. Fortunately, the philosopher and his work were interesting enough to get on without it.