The Scope or Descartes's Reason (冨田恭彦教授 退職記念号)

Abstract

In this paper, I discuss the problems of Descartes's 'reason'. Particularly, I will consider what his definition of reason is. First, I confirm what Descartes says about reason in his Discourse on Method (1637). For Descartes, 'reason' is the ability to judge correctly, and to distinguish the true from the false. Descartes uses 'reason' to pursue the truth, and to proceed in this search, it is important for him to establish the 'method', 'rules', and 'criterion' by which to distinguish the true from the false. In section 2 and after, I consider them one by one, and examine critically the extent to which the attempt of his pursuit of truth through 'reason' has been achieved. In section 1, I have argued about the purpose of reason in Descartes's philosophy, which is to Descartes the power of judging well and of distinguishing the true from the false. And then we have seen in section 3 that methodological doubts are one of the most typical concrete examples of analysis. In analysis, Descartes judges that things which have a slight possibility of doubt are false, then he examines whether any kind of truth remains after thorough doubting. At last, he reaches the truth, 'I think, therefore I am'. In order to discover something previous in 'the order corresponding to one's own perception', he employs methodological doubts. However, in the last section of this paper, we have seen that Descartes's logical structure of these methodological doubts has defects. It is a patent fact that, by using his own reason, Descartes could arrive at a metaphysical truth. However, we cannot call an argument based on this sort of reasoning a sufficiently valid one: therefore, this fact shows the imperfection in his reasoning. Nevertheless, it's still clear that Descartes's attempt to pursue the truth reveals how far reason can take us.