April 21, 1911] 



SCIENCE 



611 



special definitions ad hoc, of his own formula- 

 tion, as an indication of the particular doc- 

 trines with which he is for the time being 

 concerned. This, of course, is a perfectly 

 legitimate procedure; but even this wise pre- 

 ■caution can free the ensuing discussion from 

 irrelevancy and terminological confusion only 

 upon three conditions: first, that the defini- 

 tion itself be unequivocal; second, that the 

 -writer subsequently use the term only in the 

 ■sense defined; and third, that the sense given 

 .to it by his definition correspond to doctrines 

 actually held by contemporary writers worth 

 considering, and to the fundamental prin- 

 -ciples of those doctrines rather than to their 

 .adventitious details. I am not quite sure 

 that the first two conditions are wholly ful- 

 filled in Professor Hitter's discussion ; his defi- 

 aiition of vitalism seems to me diffuse and of 

 rather elusive meaning, and it does not seem 

 altogether clear that the vitalism with which 

 some of his remarks deal is the vitalism de- 

 fined. These, however, are merely questions 

 ■of verbal consistency upon which it would be 

 unprofitable to dilate. Of more material con- 

 sequence is the third requirement; for if it be 

 not fulfilled, the discussion, however clear and 

 unambiguous, is unlikely to be pertinent to 

 the controversy over vitalism, as an important 

 •contemporary issue. Do, then, Professor Eit- 

 ter's definitions really expose the nerve of that 

 issue? I am not convinced that they do. 

 In order, however, to avoid a merely ad hom- 

 inem argument, I should like to suggest an- 

 other way of approaching the matter which 

 seems to me more likely to expedite an ending 

 of the controversy between mechanism and 

 vitalism. I shall do so by indicating in the 

 •order of their logical priority what appear to 

 be the three essential questions involved in 

 the controversy, and the nature of the oppo- 

 -sing views which may be, and have been, taken 

 upon each of these questions. 



1. The first question concerns the logical re- 

 lation of the " laws " or generalizations of 

 biology to those of other sciences. The meeh- 

 ..anistie doctrine, whatever more it may imply, 

 at least asserts that the explanations of or- 

 ,ganie processes can eventually be found in 



the laws of some more " fundamental " science 

 whose generalizations are more comprehensive 

 than those of biology, covering some (or all) 

 inorganic phenomena, as well as organic. The 

 full mechanistic program would be realized if 

 biological laws could be shown to be special 

 eases of chemical laws, these in turn of phys- 

 ical, and these finally of the laws of mechanics. 

 Eoux, for example, thus sets down the aspira- 

 tion of the science of EntwicMungsmechanik : 

 Das organische Geschehen . . . auf anorgan- 

 ische Wirhungsweisen zurilcTczufuhren, es in 

 solche Wirhungsweisen zu zerlegen, zu ana- 

 lysieren. The vitalist, on the other hand, 

 however much more he may assert, maintains 

 at least the impossibility of this reduction of 

 organic processes to the laws of the sciences 

 of the inorganic. The first article of the 

 creed of the recent defenders of vitalism, and 

 perhaps the one article on which they are all 

 agreed, is the principle of Lebensautonomie, 

 which is thus formulated by von Hartmann: 

 Aus anorganischer Materie Jcann das Organ- 

 ische von selbst, d. h. naeh anorganischer 

 Gesetzlichkeit allein, nicht enistehen. 



But what precisely is the matter at issue 

 here, and by what test, if it were available, 

 could the issue be decided? In what would 

 a Zumclcfiihrung of biology to chemistry or 

 physics consist? It would consist in showing 

 that a given organic process A can be sub- 

 sumed under and deduced from a given gen- 

 eralization, B, of the more " fundamental " 

 science. The proof of the autonomy of biol- 

 ogy, on the other hand, would consist in show- 

 ing that there are modes of action character- 

 istic of matter when organized into a living 

 body which can never be deduced from any 

 law that describes any modes of action of 

 inorganic matter. But here an explanation 

 about deducibility is needful, since the notion 

 has been somewhat confused in some recent 

 discussions. From no general law alone, even 

 if it is known to be true, can any more special 

 law, or individual phenomenon, be deduced; 

 and this follows from the very notion of a 

 scientific law. For such laws are generalized 

 statements of certain constant correlations 

 between two or more variables; and in order 



