INTRODUCTION 



THE history of the evolution of life, incomplete as it 

 yet is, already reveals to us how the intellect has been 

 formed, by an uninterrupted progress, along a line which 

 ascends through the vertebrate series up to man. It 

 shows us in the faculty of understanding an appendage 

 of the faculty of acting, a more and more precise, more 

 and more complex and supple adaptation of the con 

 sciousness of living beings to the conditions of exist 

 ence that are made for them. Hence should result 

 this consequence that our intellect, in the narrow 

 sense of the word, is intended to secure the perfect 

 fitting of our body to its environment, to represent the 

 relations of external things among themselves in 

 short, to think matter. Such will indeed be one of 

 the conclusions of the present essay. We shall see 

 that the human intellect feels at home among inanimate 

 objects, more especially among solids, where our action 

 finds its fulcrum and our industry its tools ; that our 

 concepts have been formed on the model of solids ; 

 that our logic is, pre-eminently, the logic of solids ; 

 that, consequently, our intellect triumphs in geometry, 

 wherein is revealed the kinship of logical thought with 

 unorganized matter, and where the intellect has only 

 to follow its natural movement, after the lightest 

 possible contact with experience, in order to go from 



