160 FRAGMENTS OF SCIENCE 



word "neglect" implies mere intellectual misdirection, 

 whereas in Aristotle, as in Groethe, it was not, I believe, 

 misdirection, but sheer natural incapacity which lay at 

 the root of his mistakes. As a physicist, Aristotle dis- 

 played what we should consider some of the worst of 

 attributes in a modern physical investigator — indistinct- 

 ness of ideas, confusion of mind, and a confident use 

 of language which led to the delusive notion that he 

 had really mastered his subject, while he had, as yet, 

 failed to grasp even the elements of it. He put words 

 in the place of things, subject in the place of ob- 

 ject. He preached Induction without practicing it, in- 

 verting the true order of inquiry, by passing from 

 the general to the particular, instead of from the par- 

 ticular to the general. He made of the universe a closed 

 sphere, in the centre of which he fixed the earth, prov- 

 ing from general principles, to his own satisfaction and 

 to that of the world for near 2,000 years, that no other 

 universe was possible. His notions of motion were en- 

 tirely unphysical. It was natural or unnatural, better or 

 worse, calm or violent — no real mechanical conception re- 

 garding it lying at the bottom of his mind. He afiirmed 

 that a vacuum could not exist, and proved that if it did 

 motion in it would be impossible. He determined a priori 

 how many species of animals must exist, and showed on 

 general principles why animals must have such and such 

 parts. When an eminent contemporary philosopher, who 

 is far removed from errors of this kind, remembers these 

 abuses of the d priori method, he will be able to make 

 allowance for the jealousy of physicists as to the accept- 

 ance of so-called d priori truths. Aristotle's errors of de- 

 tail, as shown by Eucken and Lange, were grave and 



