26 THE BIOLOGICAL PROBLEM 



on this subject, most of the discussions resting on misunder- 

 standings. Religious questions, which are entirely separate, 

 have been injected into these discussions and walls have been 

 raised which prevent each party from observing what takes 

 place at his neighbour's. Rehgion is a total stranger to these 

 problems. It is necessary to be absolutely convinced of this 

 in order to discuss them intelligently and fruitfully. 



Descartes was a pure mechanist, and yet was a true believer. 

 Claude Bernard, like most physiologists, admits a force, a 

 vital impulse, but has no religious faith. From the point of 

 view of pure method, Claude Bernard is more strictly Cartesian 

 than Descartes. Ignorance of facts was at the base of Bichat's 

 spirituahsm, just as ignorance of facts is at the base of modern 

 materialism. Every doctrine a priori other than the respect 

 of the experimental fact is harmful and dangerous in science. 

 The scientist should be a man of good faith before being a 

 philosopher, a moralist, or even a citizen. Alas, should good 

 faith be rarer than faith? It is useless to add that I have not 

 only reference to religious but also to anti-religious faith. 

 Although arising from a different source, the latter results in 

 similar consequences and, in addition, kills hope. 



To what degree can we actually accept the determinism 

 which was the foundation of Claude Bernard's method? 



*Life introduces absolutely no difference in the experi- 

 mental scientific method which must be applied to the study 

 of physiological phenomena, and in this respect the physio- 

 logical sciences and the physico-chemical sciences depend 

 on identically the same principles of investigation. In 

 living as in inorganized matter the laws are immutable, and 

 the phenomena which are governed by these laws are 

 bound to their condition of existence by a necessary and 

 absolute determinism.' 



These lines, extracted from the Introduction^ constitute a 

 true act of faith or, if one prefers, a bold and very fruitful 

 extrapolation; for it was evidently impossible in 1865 to 



