238 



THE POPULAR SCIENCE MONTHLY. 



is not that the method in which science 

 iinds its completion? Did it weaken 

 the induction made by Mr. Spencer, to 

 show that tlie facts are deducible from 

 a general law in the redistributions of 

 matter and motion ? "VVas the induction 

 made by Kepler respecting the laws of 

 planetary motion weakened when New- 

 ton proved those laws to be deducible 

 from the law of gravitation ? If so, 

 then truths are scientific only so long as 

 they remain empirical generalizations, 

 and become unscientific when they are 

 reduced to the form of rational gener- 

 alizations. In pursuance of this view 

 we may say that, so long as the geomet- 

 rical truth, that the square of the hy- 

 pothenuse of a right-angled triangle is 

 equal to the squares of the other two 

 sides, is recognized as experimentally 

 true, it constitutes a part of real sci- 

 ence, but that it becomes metaphysical 

 and worthless when it is shown to fol- 

 low inevitably from necessary axioms 

 and postulates. The strictures of the 

 author of "German Darwinism," lev- 

 eled at Spencer as an a priori thinker, 

 thus spend their force against complete- 

 ness of scientific method. The reproach 

 cast upon him could have had no pos- 

 sible ground, if in elucidating the law 

 of evolution Mr. Spencer had left it in 

 the form of a generalization based upon 

 all orders of phenomena astronomical, 

 geological, biological, psychological, and 

 sociological that is, if he had left the 

 work half done. But when the law is 

 explained, or when the universal course 

 of transformation is shown to result 

 from certain universal laws of physical 

 action laws which are themselves in- 

 ductively established before they are 

 deductively applied then Mr. Spencer 

 is to be discredited as a mere speculat- 

 ing metaphysician. It is now admitted 

 as a principle a universal principle 

 that force can neither come out of 

 nothing nor disappear into nothing. It 

 is " conserved," say some physicists ; 

 it "persists," says Mr. Spencer, and its 

 persistence is an ultimate truth. The 



laws of physical action which result in 

 evolution, undeniable as they severally 

 are, are shown by Mr. Spencer to be all 

 corollaries from this ultimate truth. 

 They are established by induction, they 

 are explained and verified by proving 

 that they are consequences of a univer- 

 sal principle ; therefore Mr. Spencer is 

 metaphysical and unscientific. 



The Nation declares that " there is 

 nothing in Spencer's writing relating to 

 what is really honored by men of sci- 

 ence (namely, the scientific explanation 

 of the origin of species) that is not to 

 be credited either to Lamarck or Dar- 

 win." Lamarck is to be credited with 

 the sagacious perception, and the cou- 

 rageous avowal, in opposition to Cuvier 

 and the whole science of his time, of 

 the doctrine of the variability of species, 

 and the thinness of the partition be- 

 tween species and varieties. He saw 

 many facts that led him to deny the 

 Cuverian dogma of the fixity of species, 

 and he had a strong conviction that 

 their variation was in some way con- 

 nected with surrounding conditions. 

 That is, Lamarck has the great merit 

 of having perceived the nature of the 

 biological problem that was yet to be 

 solved, but he can hardly be said to 

 have entered upon its solution, Mr. 

 Darwin is to be credited with the sa- 

 gacious working out of one of the con- 

 ditions of that problem, namely, the 

 influence of natural selection in giving 

 rise to the diversities of species. But 

 the achievements of both Lamarck and 

 Darwin only bring us to the threshold 

 of the great general question of which 

 they form a part. If their positions 

 are held to be valid, they simply open 

 the door to a new and immense scien- 

 tific investigation which has for its ob- 

 ject to determine the conditions, pro- 

 cesses, and causes of evolution. That 

 natural selection is not evolution, but 

 only one of its elements, and that Mr. 

 Darwin has never engaged in the inves- 

 tigation of evolution in its general prin- 

 ciples as Science is bound to consider it, 



