112 HISTORY AND SIGNIFICANCE OF SCIENCE 



this concept, for Roger Bacon and Leonardo were before 

 him. But more than any man of his day he gave impetus to 

 the doctrine that in science rests the progress of the future. 10 



What Francis Bacon accomplished in the popular mind 

 Rene Descartes (1596-1650) accomplished in philosophical 

 thought. The full significance of the scientific discoveries 

 of the Renaissance would have remained unappreciated, had 

 it not been for the extension of the method of science which 

 was begun by Descartes. The scholastic system of thought 

 was doomed by the discovery of scientific facts, but it was 

 not overthrown until it could be replaced by a system based 

 upon the new knowledge. Descartes produced the first 

 great philosophy which was independent of scholastic tradi- 

 tion and in agreement with the science of the period. More 

 than any other he may be regarded as the founder of modern 

 philosophical thinking; since he gave the necessary impetus 

 to the scientific method by his insistence upon the subjec- 

 tion of every opinion to critical examination. The Cartesian 

 doubt is nothing more than scientific skepticism regarding 

 traditional assumptions. The mechanistic conception of 

 nature, which Descartes set forth as the necessary condition 

 of scientific study, is the underlying assumption of all mod- 

 ern investigation in the exact sciences. 11 



The critical examination by John Locke (1632-1704) 

 of the limits of the human understanding was a further step 

 in the development of a scientific philosophy. It was also 

 the forerunner of eighteenth century thinking as exempli- 

 fied by David Hume (1711-1776) and Immanuel Kant 



10 This belief has since been often and clearly stated. Among recent writers, 

 it is vividly set forth by E. Ray Lankester, in the opening chapter of a volume 

 entitled: "The Kingdom of Man," where, under the heading "Nature's In- 

 surgent Son," man is pictured as an insurgent who has rebelled against nature 

 and gone so far in his rebellion there can be no turning back. 



11 An excellent summary of the nature and significance of the thought of 

 Descartes may be found in the familiar essay by T. H. Huxley, entitled: "On 

 Descartes' Discourse touching the method of using one's reason rightly and of 

 seeking scientific truth," Vol. I, "Collected Essays." 



