On The Mechanistic Philosophy Of Descartes

The purpose of this paper is to interprete the mechanical philosophy of Descartes'.Compared with the natural philosophy of Aristotle, Descartes extends the principle of mechanics to all the natural sciences, and he lays a metaphysical foundation under this theoretical conversion with the principle of the dichotomy between soul and body, which causes a foundamental change of human worldview. And compared with his contemporary empiricist mechanical theories, Descartes' philosophy is rather systematic and radical because of his insisting upon the metaphysical principle of the dichotomy between soul and body. So, making clear the metaphysical foundation of Descartes' philosophy is the first step for us to understand Descartes' mechanical philosophy.In order to oppose Aristotle's natrual philosophy, the main purpose of Descartes' metaphysics can be summarized as " to establish the dichotomy between soul and body". And in order to understand the whole discursive process which leads to this conclusion, we need to begin with the earlier time when Descartes' thoughts didn't show the metaphysical conversion. In the time of Règles, Descartes' philosophy is a kind of epistemology whose foundation is the "intuition", whose ability to offer the truth is beyond doubt; but in the time after the metaphysical conversion, Descartes' argumentation begins with the doubt paid to the intuition's such an ability, which is called by Descartes as "hyperbolic doubt". So only after understanding the mechanism of such a "hyperbolic doubt", we can make clear the meaning of Cogito, which puts an end to the whole process of universal doubts. Thinking is made of "will" and "perception", and only the thinking which embodies human's free will can be considered as the essence of soul. I think this is the first metaphysical root of Descartes' mechanical philosophy.For Descartes, the next task is to prove the essence and the existence of body. Related to the final purpose of metaphysical arguments, Descartes doesn't need only to show that in human consciousness there is an idea of body whose essence is 'extension', but he must prove that this idea represent the real body which subsists independentaly outside human consciousness. This is an "making-objective" process from the idea of body to the body itsel, so Descartes' argument needs the support of the principle of certainty of knowledge "all the things which we know clearly and distinctly are true"——this is, according to our interpretation, a principle about how to make perceptions objective. After we make clear the meaning of such a principle and other related factors of Descartes' argument, we can find that in Descartes' philosophy, the essence of body is extension, whose movement is constraint and is short of free will.The soul has free will, whose essence is thinking; the body doesn't have that one, whose essence is extension. This dualist metaphysical root is the foundation of Descartes' mechanical physics. Compared with Newton's physics, Descartes doesn't agree to interprete the interaction between celestial bodies with gravitational force which has the ultra-distance effect. This is because Descartes thinks that such a force takes the force exerted by the human beings when they makes a volitional behavior as the analogical root. In Descarts' systmem, this force embodies human's free will and belongs to the action exerted by the soul to the body, so it can't be compared to celestial bodies. And Compared with Aristotle's physics, if we relate the problem about the cause of end to the one about "free will", we can understand some profonder difference between Aristotle and Descartes. Relatively, Decartes' rather radical mechanical view of life is also determined by his metaphysical principle: animals don't have free will, but they have life, so biology, as physics, needing nothing but the mechanial principle to interprete life.