THE SYNTHETIC PHILOSOPHY AN ORGANON OF THE SCIENCES. 657 
A fundamental difference between the old and the new theory of biology is 
that while the former endeavored to explain the diverse forms of life on teleolog- 
ical principles, the latter regards environing relations as an essential factor in 
solving such problems. Between the organism and its environment there is a con- 
tinual interaction which must, in the course of long ages, produce specific and 
well marked modifications. The law of Natural Selection, as proposed by Dar- 
win as an explanation of the manner in which present existing species have been 
developed from pre-existing ones, is based on the principle of adaptive changes 
which organisms must undergo in order to adjust themselves to changes in envi- 
roning relations. ‘The truth of this law derives strong support from the consider- 
ation that organisms are not such fixed and immutable forms as they were formerly 
supposed to be. It is clearly shown that this was especially the case during 
geologic time when types were /lwent, so to speak, and less subject to the law of 
limit, so that there was a transformation of one species into another. During 
the mesuzoic period geology shows that there were comprehensive types in which 
fish, reptile, bird and beast seemed to flow into one another. The law of Nat- 
ural Selection is not inconsistent with the operation of other causes in the devel- 
opment of species. Wallace, Mivart and LeConte, while assigning to this law an 
important sphere of action, contend for other causes, even supernatural fads. 
Evolution is the only hypothesis which affords an explanation of the empiric 
principles of biology. As the undulatory theory of light is the only hypothesis 
capable of explaining all the facts in the case, so Evolution is the only hypothesis. 
which has yet been offered capable of explaining the successions of species 
during the life-history of the earth. Evolution, having no rival theory as to the 
origin of species, has been almost as generally received by biologists as the undu- 
latory theory of light has been by physicists. As to the account of the miracu- 
lous creation in the first chapter of Genesis, this sets up no rival theory against 
evolution, for it leaves the origin of species an open question. The continuity 
and succession of events implied in evolution are not inconsistent with occasional 
manifestations of supernatural power. This occasional manifestation of super- 
natural power in the form of /a¢s is all that is taught in Genesis. The entire 
organic world was due to three fa/s, one for the creation of vegetable life, one for 
the creation of animal life, and one for the creation of man. But it is plainly 
implied that these miraculous /fia¢s were instantaneous manifestations of divine 
power, while geology teaches that the development of the myriad forms of life 
was a long process, extending over countless ages, during which time organic 
species arose in an ever advancing gradation. While, then, the beginning of 
those long periods termed days was marked by a supernatural faz, their duration 
was an unbroken evolution of the effects of those fiats, during which the succes- 
sions of life, from species to species, went forward according to the working of 
natural law. ‘There is, therefore, no reason why evolution should not be recog- 
nized as a fundamental principle of theology as well as of science, so far as the 
former needs to recognize any theory regarding the method of creation. The evo- 
