_Modern Views._--The doctrine of Descartes that existence depended upon thought naturally led his followers to maintain that the mind is always thinking and consequently that dreaming is continuous. Locke replied to this that men are not always conscious of dreaming, and it is hard to be conceived that the soul of the sleeping man should this moment be thinking, while the soul of the waking man cannot recollect in the next moment a jot of all those thoughts. That we always dream was maintained by Leibnitz, Kant, Sir W. Hamilton and others; the latter refutes the argument of Locke by the just observation that the somnambulist has certainly been conscious, but fails to recall the fact when he returns to the normal state.
It has been commonly held by metaphysicians that the nature of dreams is explained by the suspension of volition during sleep; Dugald Stewart asserts that it is not wholly dormant but loses its hold on the faculties, and he thus accounts for the incoherence of dreams and the apparent reality of dream images.
Cudworth, from the orderly sequence of dream combinations and their novelty, argues that the state arises, not from any "fortuitous dancings of the spirits," but from the "phantastical power of the soul." According to K. A. Scherner, dreaming is a decentralization of the movement of life; the ego becomes purely receptive and is merely the point around which the peripheral life plays in perfect freedom. Hobbes held that dreams all proceed from the agitation of the inward parts of a man's body, which, owing to their connexion with the brain, serve to keep the latter in motion. For Schopenhauer the cause of dreams is the stimulation of the brain by the internal regions of the organism through the sympathetic nervous system. These impressions the mind afterwards works up into quasi-realities by means of its forms of space, time, causality, &c.
BIBLIOGRAPHY.--For full lists of books and articles see J. M. Baldwin's _Dictionary of Philosophy_, bibliography volume (1906), and S. de Sanctis, _I Sogni_, also translated in German with additions as _Die Träume_. Important works are--Binz, _Über den Traum_, Giessler _Aus den Tiefen des Traumlebens_, Maury, _Le Sommeil et les rêves_, Radestock, _Schlaf und Traum_, Tessié, _Les Rêves_, Spitta, _Schlaf und Traumzustande_. For super-normal dreams see F. W. H. Myers, _Human Personality_, vol i, and _Proc S P R_ viii 362. For voluntary dreams see _Proc. S P R_ iv 241, xvii. 112. On prophetic dreams see _Monist_, xi 161, _Bull. Soc. Anth._ (Paris, 1901), 196, (1902), 228, _Rev. de synthèse historique_ (1901), 151, &c. On incubation see Deubner, _De incubatione_, Maury, La Magie. On the dreams of American Indians see _Handbook of American Indians_ (Washington, 1907), s v "Dreams" and "Manito." On the interpretation of dreams see Freud, _Die Traumdeutung_. Other works are F. Greenwood, _Imagination in Dreams_, Hutchinson, _Dreams and their Meanings_. (N. W. T.)