436 FRAGMENTS OF SCIENCE 



differently to different minds. By some they will be dis- 

 missed with a sneer; to others they will appeal as proofs 

 of genius on the part of those who enunciated them. 

 There are men, and by no means the minority, who, 

 however wealthy in regard to facts, can never rise into 

 the region of principles; and they are sometimes intoler- 

 ant of those who can. They are formed to plod meritori- 

 ously on the lower levels of thought, unpossessed of the 

 pinions necessary to reach the heights. They cannot real- 

 ize the mental act the act of inspiration it might well be 

 called by which a man of genius, after long pondering 

 and proving, reaches a theoretic conception which unravels 

 and illuminates the tangle of centuries of observation and 

 experiment. There are minds, it may be said in passing, 

 who at the present moment stand in this relation to Mr. 

 Darwin. For my part, I should be inclined to ascribe to 

 penetration rather than to presumption the notion of a 

 contagium animatum. He who invented the term ought, 

 I think, to be held in esteem; for he had before him the 

 quantity of fact, and the measure of analogy, that would 

 justify a man of genuis in taking a step so bold. "Nev- 

 ertheless," says Professor Yirchow, "no one was able 

 throughout a long time to discover these livyig germs 

 of disease. The sixteenth century did not find them, nor 

 did the seventeenth, nor the eighteenth." But it may be 

 urged, in reply to this, that the theoretic conjecture often 

 legitimately comes first. It is the forecast of genius which 

 anticipates the fact and constitutes a spur toward its dis- 

 covery. If, instead of being a spur, the theoretic guess 

 rendered men content with imperfect knowledge, it would 

 be a thing to be deprecated. But in modern investigation 

 this is distinctly not the case; Darwin's theory, for exam- 



