which could not meet the tests of natural selection and the struggle for existence, was from the beginning doomed to lip-service and futility. Conduct, like anything else, should be called good or bad as it is well adapted, or mal-adapted, to the ends of life; "the highest conduct is that which conduces to the greatest length, breadth, and completeness of life."[1] Or, in terms of the evolution formula, conduct is moral according as it makes the individual or the group more integrated and coherent in the midst of a heterogeneity of ends. Morality, like art, is the achievement of unity in diversity; the highest type of man is he who effectively unites in himself the widest variety, complexity, and completeness of life.
This is a rather vague definition, as it must be; for nothing varies so much, from place to place and from time to time, as the specific necessities of adaptation, and therefore the specific content of the idea of good. It is true that certain forms of behavior have been stamped as good—as adapted, in the large, to the fullest life—by the sense of pleasure which natural selection has attached to these preservative and expansive actions. The complexity of modern life has multiplied exceptions, but normally, pleasure indicates biologically useful, and pain indicates biologically dangerous, activities.[2] Nevertheless, within the broad bounds of this principle, we find the most diverse, and apparently the most hostile, conceptions of the good. There is hardly any item of our Western moral code which is not somewhere held to be immoral; not only polygamy, but suicide, murder of one's own countrymen, even of one's parents, finds in one people or another a lofty moral approbation.
