Excerpt
I. What Evolution Is.
This the age of evolution. The word is used by many men in many senses, and still oftener perhaps in no sense at all. By some it is spoken with a haunting dread as though it were another name for the downfall of religion and of social stability. Still others speak it glibly and joyously as though progress and freedom were secured by the mere use of the name. “The word evolution (Entwickelung),” says a German writer, “fills the vocal chords more perfectly than any other word.” It explains everything, and “puts the key to the universe into one’s vest pocket.”
So various has been the use of the word, so rarely is this use associated with any definite idea, that one hesitates to call himself an evolutionist. “Evolution” and “evolutionist” are almost ready to be cast into that “limbo of spoiled phraseology” which Matthew Arnold has found necessary for so many words in which other generations have delighted, and which they have soiled or spoiled by careless usage.
But as the word evolution is not yet put away, as it is the bugbear of many good people, and the “religion” of as many more equally good, it may be worth while to consider what it still means, and what it does not mean. For if we that use the word can agree on a definition, half our quarrel is over.
It seems to me that the word evolution is now legitimately used in four different senses. It is the name of a branch of science. It is a theory of organic existence. It is a method of investigation, and it is the basis of a system of philosophy.
The Science of Organic Evolution, or Bionomics. As a science, evolution is the study of changing beings acted upon by unchanging laws. It is a matter of common observation that organisms change from day to day, and that day by day some alteration in their environment is produced. It is a matter of scientific investigation that these changes are greater than they appear. They affect not only the individual animal or plant, but they affect all groups of living things, classes or races or species. No character is permanent, no trait of life without change. And as the living organism or group of organisms is undergoing alteration, so does change take place in the objects of the physical world about them. “Nothing endures,” says Huxley, “save the flow of energy and the rational order that pervades it.” The structures and objects change their forms and relations, and to forms and relations once abandoned they never return. But the methods of change are, so far as we can see, immutable. The laws of life, the laws of death, and the laws of matter never change. If the invisible forces which rule all visible things are themselves subject to modification and evolution, we have not detected it. Its cosmic movements are so fine as to defy human observation and computation. In the control of the universe we find no trace of “variableness nor shadow of turning.” “It is the law of heaven and earth, whose way is solid, substantial, vast, and unchanging.”
But the things we know do not endure....