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SCIENCE 



[N. S. Vol. XLIV. No. 1140 



biological science, and the only possible 

 physiology is biological physiology. 3 The 

 new physiology is biological physiology — 

 not bio-physics or bio-chemistry. The at- 

 tempt to analyze living organisms into 

 physical and chemical mechanism is prob- 

 ably the most colossal failure in the whole 

 history of modern science. It is a failure, 

 not, as its present defenders suggest, be- 

 cause the facts we know are so few, but be- 

 cause the facts we already know are in- 

 consistent with the mechanistic theory. If 

 it is defended it can only be on the meta- 

 physical ground that in our present inter- 

 pretation of the inorganic world we have 

 reached finality and certainty, and that we 

 are therefore bound to go on endeavoring 

 to interpret biological phenomena in the 

 light of this final certainty. This is thor- 

 oughly bad metaphysics and equally bad 

 science. It is the idea of causation itself 

 that has failed, and failed because it does 

 not take us far enough. We have not at 

 present the data required in order to con- 

 nect physical and chemical with biological 

 interpretations of our observations; but 

 perhaps the time is not far off when biolog- 

 ical interpretations will be extended into 

 what we at present look upon as the in- 

 organic world. Progress seems possible in 

 this direction, but not in the direction of 

 extending to life our present every-day 

 causal conceptions of the inorganic world. 

 I now wish to add a few words as to the 

 relation of physiology to medicine; for I 

 am one of those with an intense belief in 

 the intimate connection between the two 

 sciences, and it seems to me that the mech- 

 anistic physiology of the nineteenth cen- 



s It has been suggested to me that if a con- 

 venient label is needed for the teaching upheld in 

 this letter the word "organieism" might be em- 

 ployed. This word was formerly used in connec- 

 tion with the somewhat similar teaching of such 

 men as Bichat, von Baer and Claude Bernard. 

 Cf. Delage, L'H&edite, Paris, 1903, p. 436. 



tury has failed to take the rightful position 

 of physiology in relation to medicine. 

 What is the practical object of medicine? 

 It is to promote the maintenance and assist 

 in the reestablishment of health. But what 

 is health? Surely it is what is normal for 

 an organism. By "normal" is meant, not 

 what is the average, but what is normal in 

 the biological sense — the condition in which 

 the organism is maintaining in integrity all 

 the interconnected normals which, as I have 

 already tried to indicate, manifest them- 

 selves in both bodily structure and bodily 

 activity. 



Now for the mechanistic physiology 

 there are no interconnected normals, just 

 as in the inorganic world as at present in- 

 terpreted there are also no interconnected 

 normals. If we look through an average 

 existing text-book of physiology we find a 

 great deal about the effects of this or that 

 stimulus, a great deal also about the ex- 

 ternal mechanism and chemistry of bodily 

 activity — a great deal, in other words, 

 about what lies on the surface but never 

 takes us further. Along with this there are 

 perhaps also some inconclusive discussions 

 of the possible mechanism of such proc- 

 esses as physiological oxidation, secretion, 

 growth, muscular contraction, or nervous 

 activity. Very little will, however, be 

 found about what in reality lies still more 

 on the surface, but also penetrates deep 

 down — the maintenance within and around 

 the body of normal organized structure and 

 activity. The maintenance of the normal 

 is something for which there is no place in 

 the mechanistic physiology, since accord- 

 ing to this physiology maintenance must 

 be in ultimate analysis only an accident of 

 structure and environment — a fitful will 

 o ' the wisp which does not concern true sci- 

 ence. 



But medicine, as we have seen, is su- 

 premely interested in the physiological 

 normal. What a man sees at the bedside is 



