Concerning the changes to which the dream life is subjected in chronic psychotic persons, very few investigations have so far been made. On the other hand, timely attention has been called to the inner relationship between the dream and mental disturbance, which shows itself in an extensive agreement of the manifestations occurring to both. According to Maury,[47] Cubanis, in his _Rapports du physique et du moral_, first called attention to this; following him came Lelut, J. Moreau, and more particularly the philosopher Maine de Biran. To be sure, the comparison is still older. Radestock[54] begins the chapter dealing with this comparison, by giving a collection of expressions showing the analogy between the dream and insanity. Kant somewhere says: “The lunatic is a dreamer in the waking state.” According to Krauss “Insanity is a dream with the senses awake.” Schopenhauer terms the dream a short insanity, and insanity a long dream. Hagen describes the delirium as dream life which has not been caused by sleep but by disease. Wundt, in the _Physiological Psychology_, declares: “As a matter of fact we may in the dream ourselves live through almost all symptoms which we meet in the insane asylums.” The specific agreements, on the basis of which such an identification commends itself to the understanding, are enumerated by Spitta.[64] And indeed, very similarly, by Maury in the following grouping: “(1) Suspension or at least retardation, of self-consciousness, consequent ignorance of the condition as such, and hence incapability of astonishment and lack of moral consciousness. (2) Modified perception of the sensory organs; that is, perception is diminished in the dream and generally enhanced in insanity. (3) Combination of ideas with each other exclusively in accordance with the laws of association and of reproduction, hence automatic formation of groups and for this reason disproportion in the relations between ideas (exaggerations, phantasms). And as a result of all this: (4) Changing or transformation of the personality and at times of the peculiarities of character (perversities).” Radestock gives some additional features or analogies in the material: “Most hallucinations and illusions are found in the sphere of the senses of sight and hearing and general sensation. As in the dream, the smallest number of elements is supplied by the senses of smell and taste. The fever patient, like the dreamer, is assaulted by reminiscences from the remote past; what the waking and healthy man seems to have forgotten is recollected in sleep and in disease.” The analogy between the dream and the psychosis receives its full value only when, like a family resemblance, it is extended to the finer mimicry and to the individual peculiarities of facial expression.