3 i8 THE POPULAR SCIENCE MONTHLY.
equal, the better-schooled army prevails. Hardly any army deserves better than the Prussian- German the name JExercitus. Before a meet- ing of the physicians of that army it is not inappropriate to consider exercise somewhat in its direct physiological aspect.
Boyish excesses have brought the Darwinian doctrine into such bad repute in wide circles that I do not without consideration place myself at its point of view. Yet, whatever view of the world one may take, science, which desires to comprehend the world, will not be prevented from at once representing the world comprehensively ; since it, according to Herr Helmholtz's evident remark, must start out from this presupposition unless it is contradicted at the outset. Only me- chanical conception is science ; when supernaturalism comes in, science ceases. As the jurist takes the law, without considering equity and palliating circumstances, so the naturalist goes on to mechanical con- clusions, without regarding venerable beliefs. It is not his office to reconcile these beliefs with those conclusions.
More, the Cuvierian doctrine of repeated creations underlaid by repeated cataclysms has lost all justification since Lyell showed that goeological phenomena have proceeded without general cataclysms, and Darwin has added that species change. Now w r e can more intel- ligibly ascribe to the creating Almighty only the action of having placed a first germ of life in previously inanimate nature. Is it not, then, simpler and more worthy of that Almighty to conceive that he at once endowed matter with the power of allowing the living to arise out of itself under definite conditions, without new assistance ?
This was Leibnitz's view, and it may be said of it that even the most cautious need not be afraid of it. According to this view, it is the object of natural research to show how the living originated by mechanical processes out of the inorganic, and how, out of this doubt- less most simple life, the present organic nature has been mechanically developed. If we could succeed in filling up the scheme of the theory of descent with real contents, we should know how the series of living beings has unfolded itself during unlimited time and through numer- ous generations, according to certain norms which appear to us as laws of organization. But with this the problem would be only half solved.
Living beings are in themselves fitted to their purpose, and adapted to the external conditions of their lives ; they were always so ; and, while they transform themselves according to their surroundings, they not merely adapt themselves to their new conditions, but they also perfect themselves in our human conception. Thus, from this point of view, organic nature appears not only as a machine, but also as a self -improving machine.
This second half of the problem demands for its solution the proof that the adaptive process has gone on mechanically, and the only not wholly vague effort to give this proof that has yet been made is the