Many authors will hesitate to gather into a unit all the cases enumerated here and will prefer to emphasize the differences rather than the common characters of these groups, a view which corresponds with their preferred judgment of inversions. But no matter what divisions may be set up, it cannot be overlooked that all transitions are abundantly met with, so that the formation of a series would seem to impose itself. *Conception of Inversion.*--The first attention bestowed upon inversion gave rise to the conception that it was a congenital sign of nervous degeneration. This harmonized with the fact that doctors first met it among the nervous, or among persons giving such an impression. There are two elements which should be considered independently in this conception: the congenitality, and the degeneration. *Degeneration.*--This term _degeneration_ is open to the objections which may be urged against the promiscuous use of this word in general. It has in fact become customary to designate all morbid manifestations not of traumatic or infectious origin as degenerative. Indeed, Magnan's classification of degenerates makes it possible that the highest general configuration of nervous accomplishment need not exclude the application of the concept of degeneration. Under the circumstances, it is a question what use and what new content the judgment of "degeneration" still possesses. It would seem more appropriate not to speak of degeneration: (1) Where there are not many marked deviations from the normal; (2) where the capacity for working and living do not in general appear markedly impaired.[6] That the inverted are not degenerates in this qualified sense can be seen from the following facts: 1. The inversion is found among persons who otherwise show no marked deviation from the normal. 2. It is found also among persons whose capabilities are not disturbed, who on the contrary are distinguished by especially high intellectual development and ethical culture.[7] 3. If one disregards the patients of one's own practice and strives to comprehend a wider field of experience, he will in two directions encounter facts which will prevent him from assuming inversions as a degenerative sign. (_a_) It must be considered that inversion was a frequent manifestation among the ancient nations at the height of their culture. It was an institution endowed with important functions. (_b_) It is found to be unusually prevalent among savages and primitive races, whereas the term degeneration is generally limited to higher civilization (I. Bloch). Even among the most civilized nations of Europe, climate and race have a most powerful influence on the distribution of, and attitude toward, inversion.[8]