Although there are many people who have contributed to our modern way of thinking, if I were to choose one person who caused the radical shift of thinking that led to modernity, I would choose René Descartes (31 March 1596 – 11 February 1650). He certainly saw himself as creating a new way of thinking that he hoped would change the world.
According to his Discourse on Method, although he attended "one of the most renowned schools of Europe," he was "confounded by so many doubts and errors" that he was frustrated in his desire to "acquire a clear and assured knowledge of everything that is useful in life" (5). The one subject he admired from his schooling was mathematics, "because of the certainty and the evidence of its reasonings," but he was surprised that it had not been put to more practical use (8). He was most disappointed with philosophy, "seeing that it has been cultivated for many centuries by the most excellent minds that have ever lived and that, nevertheless, there still is nothing in it about which there is not some dispute, and consequently nothing that is not doubtful ... I deemed everything that was merely probable to be well-nigh false" (9). In other words, even though great minds have studied philosophy over the centuries, they don't come up with solid conclusions that can be known with certainty. To Descartes, anything that can't be proved as certain might as well be taken as false.
Descartes goes on to attempt to build a system of thought that has the certainty of mathematics, but can be applied to solving the problems of life, which he believed the great philosophical minds of the past had failed to do. He did this by systematically discarding every bit of knowledge of which he could not be certain. As he went through this process of doubting, he realized that he could be certain at least that he was doubting, which led to his famous statement, "I think, therefore I am." He realized that his experience of thinking established the fact of his own existence, and he used this fact as the first principle of his philosophy (32). However, his knowledge of his own existence is only as himself as a thinking thing distinct from his physical existence, and this leads him to make a distinction between "intelligent nature" and "corporeal nature" (36), which has come to be known as Cartesian Dualism.
By making this separation, Descartes was able separate concerns of the mind and the soul from concerns of the body, allowing him to treat the body as a machine. Descartes wanted to take the principles of mechanics that allowed a building to be constructed, and apply them to the physical world, and the human body (36).
In the last part of his Discourse on Method, Descartes goes into detail about what he thinks can be accomplished with this new thinking.
For these notions made me see that it is possible to arrive at knowledge that would be very useful in life and that, in place of that speculative philosophy taught in the schools, it is possible to find a practical philosophy, by means which, knowing the force and the actions of fire, water, air, the stars, the heavens, and all the other bodies that surround us ... and thus render ourselves, as it were, masters and possessors of nature. This is desirable not only for the invention of an infinity of devices that would enable one to enjoy trouble-free the fruits of the earth and all the goods found there, but also principally for the maintenance of health, which unquestionably is the first good and the foundation of all the other goods of this life... (62)
Decartes wants us to be able to understand nature in order to control it, invent useful devices, and to improve our health and quality of life, and he thinks a mathematical and mechanical approach is the best way to accomplish this. Even though Descartes still believes in God and the human soul, his dualistic approach allows him to separate issues concerning them from issues concerning the physical world. By contrast, in the philosophy of St. Thomas Aquinas, which was dominant before Descartes, the physical and the spiritual are seen as tightly integrated, and all human activity, including the study of the natural world, is directed to the goal of salvation and growth in the knowledge of God. Descartes made a substantial break from Aquinas, and is much more aligned with today's modern thought.
In summary, here is a list of important aspects of modern thought which are found in Descartes' Discourse on Method.
- A new, practical philosophy (science) must be developed that is a break from the philosophy of the past.
- It must only deal with that which can be known with certainty.
- The physical world, including the human body, is understood in a mechanical way, in isolation from the mind or spirit.
- The purpose of this knowledge is for us to become masters and possessors of nature in order to improve our health and quality of life.
I will come back to these points repeatedly in future posts as I look at the problems we wrestle with today.