Footnote 50: Schüle, _Traité clinique des maladies mentales_, Art. “Mélancolie” (French edition), pp. 21, 28. Footnote 51: G. Dumas, _Les états intellectuels dans la mélancolie_, where may be found several detailed observations. Can we trace back these two modes of manifestation to a common and deeper cause? This is Krafft-Ebing’s[52] solution: “We must consider psychic pain and the arrest of ideas as co-ordinate phenomena; and there is reason to think of a common cause, of a nutritive trouble of the brain (anæmia?), leading to a diminished expenditure of nervous activity. Taken comprehensively, melancholia may be considered as a morbid condition of the psychic organism founded on nutritive troubles, and characterised on the one hand by the feeling of pain and a particular mode of reaction on the part of the whole consciousness (psychic neuralgia), on the other by the difficulty of psychic movements (instinct, ideas), and finally, by their arrest.” Footnote 52: Krafft-Ebing, _op. cit._, vol. ii., sec. 1, chap. i. I am unwilling to incur the reproach of inferring more from facts than they contain, and of insisting on unity at any price; but it follows from the preceding that if the element of feeling is not everywhere and always primary, at least it is so in the majority of cases. Besides, it is closely connected with fundamental trophic troubles, so that we arrive at the same conclusion by another road. Dumas (_op. cit._, pp. 133 _et seq._) has insisted on the depressing influences of marshy soil, on the stagnation, the physical and moral apathy of the inhabitants of Sologne, the Dombes, the Maremma, and other regions infested by _malaria_, a condition which may be summed up in two words, sadness and resignation. These facts are quite in favour of the organic origin of melancholia. The special study of the anomalies of pleasure and pain is not important for itself alone. The formula generally admitted since Aristotle, which couples pleasure with utility, pain with what is injurious, admits of many exceptions in practice. Perhaps the constitution of a pathological group in the study of pleasure and pain may permit us to solve some difficulties, to prevent the rule and the exceptions being placed on the same plane, and unduly assimilated to one another. We shall see that this is so in one of the following chapters. CHAPTER V. THE NEUTRAL STATES. _Two methods of study—Affirmative thesis founded on observation, deduction, and psycho-physics—Negative thesis: the psychological trinity; confusion between consciousness and introspection—Diversity of temperaments._