THE MECHANISTIC CONCEPTION OF LIFE^ 



I. INTRODUCTORY 



It is the object of. this paper to discuss the question 

 whether our present knowledge gives us any hope that 

 ultimately life, i.e., the sum of all life phenomena, can be 

 unequivocally explained in physico-chemical terms. If on 

 the basis of a serious survey this question can be answered 

 in the affirmative our social and ethical life will have to be 

 put on a scientific basis and our rules of conduct must 

 be brought into harmony with the results of scientific 

 biology. 



It is seemingly often taken for granted by laymen that 

 "truth" in biology, or science in general, is of the same order 

 as "truth" in certain of the mental sciences; that is to say, 

 that everything rests on argument or rhetoric and that what 

 is regarded as true today may be expected with some proba- 

 bility to be considered untrue tomorrow. It happens in sci- 

 ence, especially in the descriptive sciences like paleontology or 

 zoology, that hypotheses are forwarded, discussed, and then 

 abandoned. It should, however, be remembered that modern 

 biology is fundamentally an experimental and not a descrip- 

 tive science ; and that its results are not rhetorical, but always 

 assume one of two forms: it is either possible to control a 

 life phenomenon to such an extent that we can produce it at 

 desire (as, e.g., the contraction of an excised muscle); or we 

 succeed in finding the numerical relation between the con- 

 ditions of the experiment and the biological result (e.g., 



1 Address delivered at the First International Congress of Monists at Ham- 

 burg, September 10, 1911; reprinted from Popular Science Monthly, January, 

 1912, by courtesy of Professor J. McKeen CatteU. 



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