Science, however, has found, together with these physical stigmata, others of a mental order, which betoken degeneracy quite as clearly as the former; and they allow of an easy demonstration from all the vital manifestations, and, in particular, from all the works of degenerates, so that it is not necessary to measure the cranium of an author, or to see the lobe of a painter’s ear, in order to recognise the fact that he belongs to the class of degenerates. Quite a number of different designations have been found for these persons. Maudsley and Ball call them ‘Borderland dwellers’--that is to say, dwellers on the borderland between reason and pronounced madness. Magnan gives to them the name of ‘higher degenerates’ (_dégénérés supérieurs_), and Lombroso speaks of ‘mattoids’ (from _matto_, the Italian for insane), and ‘graphomaniacs,’ under which he classifies those semi-insane persons who feel a strong impulse to write. In spite, however, of this variety of nomenclature, it is a question simply of one single species of individuals, who betray their fellowship by the similarity of their mental physiognomy. In the mental development of degenerates, we meet with the same irregularity that we have observed in their physical growth. The asymmetry of face and cranium finds, as it were, its counterpart in their mental faculties. Some of the latter are completely stunted, others morbidly exaggerated. That which nearly all degenerates lack is the sense of morality and of right and wrong. For them there exists no law, no decency, no modesty. In order to satisfy any momentary impulse, or inclination, or caprice, they commit crimes and trespasses with the greatest calmness and self-complacency, and do not comprehend that other persons take offence thereat. When this phenomenon is present in a high degree, we speak of ‘moral insanity’ with Maudsley;[9] there are, nevertheless, lower stages in which the degenerate does not, perhaps, himself commit any act which will bring him into conflict with the criminal code, but at least asserts the theoretical legitimacy of crime; seeks, with philosophically sounding fustian, to prove that ‘good’ and ‘evil,’ virtue and vice, are arbitrary distinctions; goes into raptures over evildoers and their deeds; professes to discover beauties in the lowest and most repulsive things; and tries to awaken interest in, and so-called ‘comprehension’ of, every bestiality. The two psychological roots of moral insanity, in all its degrees of development, are, firstly, unbounded egoism,[10] and, secondly, impulsiveness[11]--_i.e._, inability to resist a sudden impulse to any deed; and these characteristics also constitute the chief intellectual stigmata of degenerates. In the following sections of this work, I shall find occasion to show on what organic grounds, and in consequence of what peculiarities of their brain and nervous system, degenerates are necessarily egoistical and impulsive. In these introductory remarks