THE GROWTH OF TRUTH n 



apt to be abused and ill-treated. All this is common 

 among common men, but there is something much 

 worse which has been illustrated over and over again 

 in history. How eminent soever a man may become 

 in science, he is very apt to carry with him errors 

 which were in vogue when he was young errors that 

 darken his understanding, and make him incapable of 

 accepting even the most obvious truths. It is a great 

 consolation to know that even Harvey came within the 

 range of this law in the matter of the lymphatic system 

 it is the most human touch in his career. 



By no single event in the history of science is the 

 growth of truth, through the slow stages of acquisition, 

 the briefer period of latent possession, and the for us 

 glorious period of conscious possession, better shown 

 than in the discovery of the circulation of the blood. 

 You will all agree with me that a Fellow of this college 

 must take his courage in both hands who would, in this 

 place and before this audience, attempt to discuss any 

 aspect of this problem. After nearly three centuries of 

 orations the very pictures and books in this hall might 

 be expected to cry out upon him. But I have so taken 

 my courage, confident that in using it to illustrate 

 certain aspects of the growth of truth I am but obeying 

 the command of Plato, who insists that principles such 

 as these cannot be too often or too strongly enforced. 

 There is a younger generation, too, the members of 

 which are never the worse for the repetition of a good 

 story, stale though it may be in all its aspects to their 

 elders ; and then there is that larger audience to be 

 considered to which the season is never inappropriate 

 to speak a word. 



