It is also not without importance to note that, whenever genius appears in a race, the number of the insane also increases. Of this fact we have found remarkable proofs among the Italian, German, and English Jews. So much is this the case, that it is the custom, in German lunatic asylums, to reckon genius in the parents among the etiological elements of insanity. Both genius and insanity are influenced by violent passions at the time of conception, by advanced age, or alcoholism in the parents; and as, in all degenerate natures, genius is only exceptionally transmitted, it almost always assumes the form of more and more aggravated neurosis, and rapidly disappears, thanks to that beneficent sterility through which nature provides for the elimination of monsters. Though all the proofs we have given should have been forgotten, the fact would be quite sufficiently demonstrated by the pedigrees of Peter the Great, the Cæsars, and Charles V., in which epileptics, men of genius, and criminals, alternate with ever greater frequency, till the line ends in idiocy and sterility.[452] In all these three types (insanity, insane genius, and sane genius), we see at work, with nearly equal intensity, the influence of race,[453] of hot climates, of diminutions (unless greatly exaggerated), in the degree of atmospheric pressure, and, in frequent cases, of maladies accompanied by a high temperature. But the most convincing proof of all is offered by the insane who, though not possessed of genius, apparently acquire it, for a time, while under treatment. These cases prove that geniality, originality, artistic and æsthetic creation may show themselves in the least predisposed natures, as a consequence of mental alienation. Finally, not the least important proof is contained in the singular phenomenon of the mattoid, who, as distinguished from the really insane, has all the appearances, without the reality, of genius. Taking all this into consideration, we may confidently affirm that genius is a true degenerative psychosis belonging to the group of moral insanity, and may temporarily spring out of other psychoses, assuming their forms, though keeping its own special peculiarities, which distinguish it from all others. The identity of genius with moral insanity is seen in that general alteration of the affective instincts, which shows itself, more or less disguised, in all,[454] even in those rare altruistic persons with a genius for goodness to whom the name of saints has been given. This also explains their longevity. There is, beyond all doubt, some connection between all these observations, and the fact, established by Tamburini and myself, that the best artists of the asylums were all morally insane.