48 THE MAIN CURRENTS OF ZOOLOGY 



zoology was concerned, was a return to the observa- 

 tion of nature. 



This new movement was a revolt of the intellect 

 against existing conditions. In its entirety it is 

 called the Renaissance. It was several centuries in 

 gaining enough headway to break over the barriers 

 that had been stretched across the path of progress. 

 From time to time the more independent thinkers and 

 the more gifted individuals had attempted to restore 

 the practice of independent observation and thought, 

 but, repeatedly, their efforts were suppressed by 

 theological opposition. Finally, in the sixteenth cen- 

 tury, through the efforts of men like Galileo, Des- 

 cartes and Vesalius the method of scientific investiga- 

 tion was established. The renovation of intellectual 

 life began as early as the thirteenth century and 

 involved an expression of the human spirit in various 

 directions artistic, literary, scientific, etc. The 

 artistic and literary development preceded the 

 scientific, and it was not until the Renaissance was 

 well under way that the scientific revival took place. 

 In the latter was involved not only the progress of 

 zoology, but all the benefits that have accrued from 

 the development of modern science. 



Among the actors in the scientific renaissance, 



