Page:Popular Science Monthly Volume 41.djvu/18

 the doctrine of development or evolution—a doctrine which manifests itself in every essay with continually increasing distinctness, and which is thus shown to be taking year after year a stronger and stronger hold upon the author's mind and a deeper and deeper place in all his speculations.

As early as the year 1852 he had published in a periodical entitled The Leader a short but pithy paper on the Development Hypothesis, which was afterward referred to by Darwin, in the historical sketch prefixed to the Origin of Species, as presenting the general argument for the developmental as against the special-creation interpretation of the universe with remarkable cogency and skill. But, while reasons were here briefly but clearly stated for a belief in the gradual development of all organisms, not excluding man, it must be remembered that the essay does not contain any indication of factors adequate to the production of the alleged effects. One process only is recognized—the process of direct modification by the conditions of life; and, as with this process alone it is obviously impossible to account for all the facts of organic creation, the way was left open to the uniformitarians to make good a temporary escape.

But this noteworthy little paper, though it contained a kind of systematized confession of faith, was only, after all, a starting-point for a long and thorough investigation of various aspects of the subject with which it dealt. Its leading ideas, as I have said, came little by little to suffuse all his work, and in the years which followed they underwent consolidation and reached an expression at once more definite and more complete. Was it a question of deducing a theory of population from the general law of animal fertility? Then we find distinct recognition of an advance from lower to higher brought about by excessive reproduction and the continual pressure of rapidly multiplying organisms upon the slowly increasing means of support (a statement in regard to which we shall have a word to say further on). Did the discussion turn upon the elaboration on a scientific basis of a true philosophy of style? Then, along with the application to the special phenomena of expression of the general law of "the line of least resistance," there is further reached the generalization—set down as applying to all products both of man and of Nature—of those two fundamental processes of evolution—the process of differentiation and the process of integration; since it is shown that a highly developed style "will be, not a series of like parts simply in juxtaposition, but one whole made up of unlike parts that are mutually dependent." Are the right and wrong objects and methods of education brought up for consideration?