"Memory," it has been said, "is a faculty which loses nothing and records everything." [Footnote: Ball, quoted by Rouillard, Les Amnesies, Paris, 1885, p. 25; Matter and Memory, p. 201 (Fr. p. 168).] This is only too true, although normally we do not recognize it. But we can never be sure that we have absolutely forgotten anything. Illness, producing delirium, may provoke us to speak of things we had thought were gone beyond recall and which perhaps we even wish were beyond recall. A somnambulistic state or even a dream may show us memory extending far further back than we could ordinarily imagine. The facing of death in battle, we know, recalls to many, with extreme vividness, scenes of early childhood which they had deemed long since forgotten. "There is nothing," says Bergson, "more instructive in this regard than what happens in cases of sudden suffocation--in men drowned or hanged. The man, when brought to life again, states that he saw in a very short time all the forgotten events of his life, passing before him with great rapidity, with their smallest circumstances, and in the very order in which they occurred." [Footnote: La Perception du Changement, pp. 30-31, and Matter and Memory, p 200 (Fr p 168).] Hence we can never be absolutely sure that we have forgotten anything although at any given time we may be unable to recall it to mind. There is an unconscious memory.[Footnote: Cf. Samuel Butler's Unconscious Memory.] Speaking of the profound and yet undeniable reality of the unconscious, Bergson says,[Footnote: Matter and Memory, pp 181-182 (Fr. pp. 152-153). See also Le Souvenir du present et la fausse reconnaissance, Revue philosophique, Dec., 1908, p. 592, and L'Energie spirituelle, pp. 159-161 (Mind-Energy).] "Our unwillingness to conceive unconscious psychical states, is due, above all, to the fact that we hold consciousness to be the essential property of psychical states, so that a psychical state cannot, it seems, cease to be conscious without ceasing to exist. But if consciousness is but the characteristic note of the present, that is to say, of the actually lived, in short, of the active, then that which does not act may cease to belong to consciousness without therefore ceasing to exist in some manner. In other words, in the psychological domain, consciousness may not be the synonym of existence, but only of real action or of immediate efficacy; limiting thus the meaning of the term, we shall have less difficulty in representing to ourselves a psychical state which is unconscious, that is to say, ineffective. Whatever idea we may frame of consciousness in itself, such as it would be if it could work untrammelled, we cannot deny that in a being which has bodily functions, the chief office of consciousness is to preside over action and to enlighten choice. Therefore it throws light on the immediate antecedents of the decision and on those past recollections which can usefully combine with it; all