Page:Popular Science Monthly Volume 75.djvu/191

Rh we say that the new creation, the United States, contained something underived from the original states and their conditions? Shall we deny that our republic was contained potentially in the thirteen original states? Surely not. But the processes of gestation and parturition by which the nation came forth profoundly modified the elements, the states. Only a wisdom practically infinite could have foreseen exactly what those modifications would be. The criticism has been made that in using the origin of the United States as an illustration of the centripetal action of the developmental process, I am resorting to the analogical mode of reasoning, the very thing I have objected to in another connection. Attention must be called to the fact that it was not the use but the illegitimate use of this method to which objection was made. I am not pretending that the reciprocating action as it takes place in either the animal body or the nation explains the process in the other. My point is that in both cases the developmental process manifests this peculiarity. There is a common element in the two developments. That is all I am insisting on. But this must be taken in connection with the principle insisted on with equal emphasis elsewhere, that each natural object has its own qualities and properties. The man and the nation have something in common as to their mode of development, but they also have something of difference. To ascertain the differences and the traits-in-common all along the line is exactly what the business of developmental biology is.

Those biologists whose creed is that explanation of nature consists in reducing her to a few simple principles will make wry faces if nothing worse at this. But until such biologists can be more successful than they have been so far, in preventing organic chemists from finding new compounds day by day, and in suppressing systematic botanists and zoologists who persist in hunting up new kinds of plants and animals, and new characteristics and varieties of old ones, I see no prospect of these wry faces changing to expressions of good cheer.

It may be unfortunate that the living world is so complex, was not constructed on "a few simple principles." But one thing seems well established: Nature can not be made simple by treating her on the theory that she ought to be so when as a matter of fact she is not. To say that a few principles can be found that are common to very wide domains of nature, and to deny that there are numberless other principles not so widely prevalent are very different propositions.

Growth and organization everywhere in living nature work inward as well as outward. The processes turn back upon themselves and produce changes in the contributing elements. What the new creation will be, what modifications the elements will undergo, one can see beforehand partly, but never fully. Only infinite wisdom could see altogether. Notice under what conditions one's wisdom would enable him to predict the future absolutely. Would not these two conditions be essential: That his knowledge of the past should be absolute, and that the course of events, that is the laws of nature, should be absolutely trustworthy?

Observation with our senses, of law-abiding operations, perforated by objects cognizable only through their own properties, is one way of