Page:The Function of Reason.pdf/15

 existence among such organisms. But certainly this struggle throws no light whatever upon the emergence of such a general type of complex organism, with faint survival power. This problem is not to be solved by any dogma, which is the product of mere abstract thought elaborating its notions of the fit- ness of things. The solution requires that thought pay full attention to the empirical evidence, and to the whole of that evidence.

The range of species of living things is very large. It stretches from mankind throughout all the vertebrates, and the insects, and the barely organized animals which seem like societies of cells, and throughout the varieties of vegetable life, and down to the minutest microscopic forms of life. At the lower end of the scale, it is hazardous to draw any sharp distinction between living things and inorganic matter. There are two ways of surveying this range of species. One way abstracts from time, and considers the variety of species as illustrating various levels of life. The other way emphasizes time, by considering the genetic relations of the species one to another.

The latter way embraces the doctrine of evolution, and interprets the vanishing of species and of sporadically variant individuals, as being due to maladjustment to the environment. This explanation has its measure of truth: it is one of the great generalizations of science. But enthusiasts have so strained its interpretation as to make it explain nothing, by reason of the fact that it explains