Introduction

We must now take cognizance of the elementary terms or relations that nature presents to us in perception. These terms and these relations indeed form the very texture of its structure; the patterns which they offer will be the features of the object of geometry. But to speak of nature as a network of terms and relations seems to arouse all our philosophical scepticism. Are we not accepting a considerable postulate? What gives us the right to apply to the flux of sensation the categories of logic? There are many who would declare that reason is inadequate to the task.