The doctrine which I have called physiological (Bain, Spencer, Maudsley, James, Lange[1]) connects all states of feeling with biological conditions, and considers them as the direct and immediate expression of the vegetative life. It is the thesis which has been adopted, without any restriction, in this work. From this standpoint feelings and emotions are no longer a superficial manifestation, a simple efflorescence; they plunge into the individual’s depths; they have their roots in the needs and instincts, that is to say, in movements. Consciousness only delivers up a part of their secrets; it can never reveal them completely; we must descend beneath it. No doubt it is awkward to have to invoke an unconscious activity, to call in the intervention of an obscure and ill-determined factor; but to wish to reduce emotional states to clear and definite ideas, or to imagine that by this process we can fix them, is to misunderstand them completely and to condemn ourselves beforehand to failure. ----- Footnote 1: It may be doubted whether all the English writers here mentioned can be strictly classed with the physiological school as understood by M. Ribot. With regard to Mr. Spencer, for instance, this is indicated by a brief summary of his own position in a private letter to the Rev. Angus Mackay, who had presented a statement of the “confused intelligence” theory, “which I conceive to be a part of the truth,” wrote Mr. Spencer, adding that “joined with the dimly aroused association of ideas derived from the experiences of the individual, I hold that the body of the emotion consists more largely of the inherited associations of experiences and still more vague states of consciousness which result from excitement of them.” It is clear that the evolutionary view does not necessarily fall wholly into the “physiological” group.—ED. ----- For the rest, this is neither the place to criticise the intellectualist thesis, nor to justify the other in passing; the whole work is devoted to this task. The book consists of two parts. The first studies the more general manifestations of feeling: pleasure and pain, the characteristic signs of this form of psychic life, everywhere diffused under manifold aspects; then the nature of emotion, a complex state which in the order of feelings corresponds to perception in the order of knowledge.