[1] A Danish alienist, Lange, has, however, made an attempt on a statistical basis to show a connection between mental ability and mental degeneracy. (F. Lange, Degeneration in Families, translated from the Danish, 1907). He deals with 44 families which have provided 428 insane or neuropathic persons within a few generations, and during the same period a large number also of highly distinguished members, Cabinet ministers, bishops, artists, poets, etc. But Lange admits that the forms of insanity found in these families are of a slight and not severe character, while it is clear that the forms of ability are also in most cases equally slight; they are mostly "old" families, such as naturally produce highly-trained and highly placed individuals. Moreover, Lange's methods and style of writing are not scientifically exact, and he fails to define precisely what he means by a "family." His investigation indicates that there is a frequent tendency for men of ability to belong to families which are not entirely sound, and that is a conclusion which is not seriously disputed.
[2] Havelock Ellis, A Study of British Genius, 1904.
[3] Dr. Cabanès (Indiscrétions de l'Histoire, 3rd series) similarly concludes that, while in temperament Napoleon may be said to belong to the epileptic class, he was by no means an epileptic in the ordinary sense. Kanngiesser (Prager Medizinische Wochenschrift, 1912, No. 27) suggests that from his slow pulse (40 to 60) Napoleon's attacks may have originated in the heart and vessels.
[4] Genuine epilepsy usually comes on before the age of twenty-five; it very rarely begins after twenty-five, and never after thirty. (L.W. Weber, Münchener Medizinische Wochenschrift, July 30th and Aug. 6th, 1912.) In genuine epilepsy, also, loss of consciousness accompanies the fits; the exceptions to this rule are rare, though Audenino, a pupil of Lombroso, who sought to extend the sphere of epilepsy, believes that the exceptions are not so rare as is commonly supposed (Archivio di Psichiatria, fasc. VI., 1906). Moreover, true epilepsy is accompanied by a progressive mental deterioration which terminates in dementia; in the Craig Colony for Epileptics of New York, among 3,000 epileptics this progressive deterioration is very rarely absent (Lancet, March 1st, 1913); but it is not found in the distinguished men of genius who are alleged to be epileptic. Epileptic deterioration has been elaborately studied by MacCurdy, Psychiatric Bulletin, New York, April, 1916.
[5] See, e.g., Elizabeth du Quesne van Gogh, Personal Recollections of Vincent van Gogh, p. 46. These epileptic attacks are, however, but vaguely mentioned, and it would seem that they only appeared during the last years of the artist's life.
XIV — THE PRODUCTION OF ABILITY
The growing interest in eugenics, and the world-wide decline in the birth-rate, have drawn attention to the study of the factors which determine the production of genius in particular and high ability in general. The interest in this question, thus freshly revived and made more acute by the results of the Great War, is not indeed new. It is nearly half a century since Galton wrote his famous book on the heredity of genius, or, as he might better have described the object of his investigation, the heredity of ability. At a later date my own Study of British Genius collectively summarised all the biological data available concerning the parentage and birth of the most notable persons born in England, while numerous other studies might also be named.
Such investigations are to-day acquiring a fresh importance, because, while it is becoming realised that we are gaining a new control over the conditions of birth, the production of children has itself gained in importance. The world is no longer bombarded by an exuberant stream of babies, good, bad, and indifferent in quality, with Mankind to look on calmly at the struggle for existence among them. Whether we like it or not, the quantity is relatively diminishing, and the question of quality is beginning to assume a supreme significance. What are the conditions which assure the finest quality in our children?