TWO THEORIES OF KNOWLEDGE 47 



are examples of the maxims derived or supposed to 

 be derived from the necessities of our Reason, and 

 by the aid of which it was vainly hoped to attain a 

 knowledge of Nature and natural laws. 



The principle was in itself unsound. 



The necessary laws of our rational faculty could 

 discover to us only the essentials of that faculty 

 itself. 



The maxims by which it was sought to constitute 

 a priori a scheme of natural laws could not justly 

 claim descent from the necessities of Thought. 

 Had the Schoolmen formed a true conception of the 

 nature of Knowledge they would never have imagined 

 that any necessity of Thought obliged them to 

 believe that a 10 Ib. weight would fall to the ground 

 more rapidly than a 1 Ib. weight. Equally true is it 

 that their scientific principles had not been derived 

 from any study of the action of natural law. They 

 were unacknowledged intellectual orphans. 



The movement associated with the names of 

 Galileo, Bruno, Bacon, Kepler, and Newton owed 

 its origin and its success to the abandonment 

 of this vicious principle. So far as Nature was 

 concerned, the Mind was regarded as a tabula rasa, 

 and the physician set himself to ascertain the laws 

 of nature not by reflection upon his own mental 

 processes or requirements, but by experiment with 



