" Of philosophy I will say nothing, except that when I saw that 

 it had been cultivated for many ages by the most distinguished 

 men, and that yet there is not a single matter within its sphere 

 which is not still in dispute, and nothing, therefore, which is above 

 doubt, I did not presume to anticipate that my success would be 

 greater in it than that of others; and, further, when I considered 

 the number of conflicting opinions touching a single matter that 

 may be upheld by learned men, while there can be but one true, 

 I reckoned as well-nigh false all that was only probable." — 

 Descabtes : The Discourse on Method. 



■' When I wrote my paper on the thymus gland, I was very con- 

 scientious about the literature on the subject. I found that many 

 memoirs had been written and published, and I looked at them 

 all — or, at least, at all of them that I could obtain. There were 

 many German works, not many French and Italian ones, and a 

 number of English papers. I collated and made abstracts of them , 

 and discussed all the results and conclusions, and, generally, 

 rounded off our knowledge with regard to the matter. Altogether 

 I found afterwards that there were fifty-two memoirs on the 

 development of the gland. My paper only made the number fifty- 

 three !" — Unpublished Letter from a Young Zoologist. 



