A HISTORY OF SCIENCE 



they are, in themselves, an essential part of the knowl- 

 edge of every cultivated person. 



It is our task, not merely to show what these prin- 

 ciples are, but to point out how they have been dis- 

 covered by our predecessors. We shall trace the 

 growth of these ideas from their first vague beginnings. 

 We shall see how vagueness of thought gave way to 

 precision; how a general truth, once grasped and 

 formulated, was found to be a stepping-stone to other 

 truths. We shall see that there are no isolated facts, 

 no isolated principles, in nature ; that each part of our 

 story is linked by indissoluble bands with that which 

 goes before, and with that which comes after. For 

 the most part the discovery of this principle or that in 

 a given sequence is no accident. Galileo and Keppler 

 must precede Newton. Cuvier and Lyall must come 

 before Darwin ; which, after all, is no more than say- 

 ing that in our Temple of Science, as in any other piece 

 of architecture, the foundation must precede the super- 

 structure. 



We shall best understand our story of the growth 

 of science if we think of each new principle as a step- 

 ping-stone which must fit into its own particular 

 niche; and if we reflect that the entire structure of 

 modern civilization would be different from what it is, 

 and less perfect than it is, had not that particular 

 stepping-stone been found and shaped and placed in 

 position. Taken as a whole, our stepping-stones lead 

 us up and up towards the alluring heights of an acrop- 

 olis of knowledge, on which stands the Temple of Mod- 

 ern Science. The story of the building of this wonder- 

 ful structure is in itself fascinating and beautiful. 



