Emotions and sentiments are necessary stimulants to action. They are indefinitely valuable in national character, but only to the extent that they are governed and directed by intelligence. In themselves they are blind and unreasoning impulses, and dangerous guides. In culture history, they belong to primitive or half-civilised people, incapable of holding rational conduct. By means of them, astute and unscrupulous rulers sway the masses, exciting them to actions detrimental to themselves.

The real factors in ethnic evolution must ever be those which are rational, conscious, voluntary. As voluntary, they require freedom, liberty of choice and of action. Freedom is an external condition, and unless it is enjoyed without other restraint than the limitation of the same privilege in others, the group can never reach its complete development. In the theory of progress, therefore, it should be always given as the primary condition of growth.

The physiological processes by which regressive variation affects the ethnic mind are chiefly three:

1. Absorption through concentration elsewhere.

2. Disuse or neglect of faculties.

3. Reaction from natural limitations.

Such changes as these are not merely consistent with ethnic advancement but essential to it. They indicate simply a re-distribution of the vital forces in accordance with the demands of new conditions. This is a phenomenon constantly seen in the individual life of organic beings of every grade, and that it extends to the species and to the mental powers proves that it is an universal law.

Many have maintained that regressive variation proceeds in an inverse direction from progressive evolution, eliminating the most recently acquired characteristics first. Not a few have sought to apply this supposed law to ethnic conditions and sociological factors. But recent authorities of weight, who have examined this question with care, regard the instances supposed to confirm such a theory as coincidences only, or explicable on other grounds.

The term “regressive,” therefore, is to be understood as applying to a physiological and healthy process, by which the sum of nutrition in an organism is expended more upon one or several elements of that organism at the expense of other elements. The latter, therefore, reduced in sustenance, undergo “regressive” changes, atrophy, or diminish.

In mental life this is paralleled by the cultivation of some faculties to the neglect of others. Those to which we “pay attention,” as the phrase is, improve, while those which we neglect are weakened.