No one will demand that every member of a group should suffer from such conditions in order that its collective mind should betray morbid consequences. It is enough if a majority, or even a decided minority, providing it exerts the requisite influence on the mass, is in such a pathological state. A degenerate nobility or a dissolute priesthood has often worked the ruin of a state through the contagion of example and its control of lower classes.
Before considering in detail the varied forms under which these diseased mental traits present themselves, it will be well to examine the general causes to which they are due.
Etiology.—Each of such pathological conditions of the ethnic mind has a basis in some prevailing physical neurosis, the origin of which can be traced in the ethnic history, and which becomes hereditary in the stock. For of these two principles no student of the subject can doubt, (1) that every pathological mental manifestation corresponds to a neuropathic change, and (2) that whatever may be said about the transmission of acquired characters in physiology, no physician can for a moment doubt that morbid infection may be passed down from generation to generation.
For these reasons the study of causes in ethnic pathology becomes of enormous practical moment. Only by an acquaintance with them can preventive and curative remedies be applied.
These causes are, at first, always external and individual. They proceed from some form of “environment,” mental or physical. But the morbid impression, once fully received, is often indelible, becomes fixed in the type, and is but little influenced by external agencies.
These primary causes of true ethnic degeneration I shall consider under four headings.
1. Imperfect Nutrition.
2. Sexual Subversions.
3. Toxic Agents.
4. Mental Shocks.