658 PR A OMEN TS F SCIENCE. 



middle ages. We have received this name from our fore- 

 fathers, and it already appears distinctly in the sixteenth 

 century. We possess several works of that time which put 

 forward contagium animatum as a scientific doctrine, with 

 the same contidence, with the same sort of proof, with 

 which the ( Plastidulic soul' is now set forth." 



These speculations of our "forefathers" will appeal 

 differently to different minds. By some they will be 

 dismissed 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- meaus the minority, who, how- 

 ever wealthy in regard to facts, can never rise into the 

 region ol principles; and they are sometimes intolerant of 

 those who can. They are formed to plod meritoriously on 

 the lower levels of thought, unpossessed of the pinions 

 necessary to reach the heights. They cannot realize 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 tho 

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

 justify a man of genius in taking a step so bold. " Never- 

 theless," says Professor Virchow, " no one was able 

 throughout a long time to discover these living 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 ex- 

 ample, like the undulatory theory, has been a motive 

 power and not an anodyne. "At last," continues Profes- 

 sor Virchow, "in the nineteenth century we have begun 

 little by little really to find contagia animata." So much 



