VERY profound philosophers have lately generalized concerning the production of living forms, and the mental and moral phenomena regarded as their highest development. Mr, Herbert Spencer's theory of Evolution purports to explain the origin of all specific differences, so that not even the rise of a Homer or a Beethoven would escape from his broad theories. The homogeneous is unstable and must differentiate itself, says Spencer, and hence comes the variety of human institutions and characters. In order that a living form shall continue to exist and propagate its kind, says Mr. Darwin, it must be suitable to its circumstances, and the most suitable forms will prevail over and extirpate those which are less suitable. From these fruitful ideas are developed theories of evolution and natural selection which go far toward accounting for the existence of immense numbers of living creatures—plants and animals. Apparent adaptations of organs and limbs to useful purposes, which Paley and other theologians regarded as distinct products of creative intelligence, are now seen to follow as natural effects of a constantly-acting tendency. Even man, according to these theories, is no distinct creation, but rather an extreme specimen of brain-development. His nearest cousins are the apes, and his pedigree extends backward until it joins that of the lowliest zoophytes.
The theories of Darwin and Spencer are doubtless not demonstrated; they are, to some extent, hypothetical, just as all the theories of physical science are to some extent hypothetical, and open to doubt. But I venture to look upon the theories of evolution and natural selection, in their main features, as two of the most probable hypotheses ever proposed, harmonizing and explaining, as they do, immense numbers of diverse facts. I question whether any scientific works which have appeared since the "Principia" of Newton are comparable in importance with those of Darwin and Spencer, revolutionizing, as they do, all our views of the origin of bodily, mental, moral, and social phenomena.
Granting all this, I cannot for a moment admit that the theory of Evolution will alter our theological views. That theory embraces several laws, or uniformities, which are observed to be true in the production of living forms; but these laws do not determine the size and figure of living creatures, any more than the law of gravitation determines the magnitudes and distances of the planets. Suppose that Darwin is correct in saying that man is descended from the Ascidians;
- Abstracted from the closing chapter of "The Principles of Science: A Treatise on Logic and Scientific Method."