life; they represent the two complementary aspects of one and the same fundamental tendency, the tendency of every organism to extract from a given situation that in it which is useful, and to store up the eventual reaction in the form of a motor habit, that it may serve other situations of the same kind.
Let us jump now to the other extremity of our mental life, and, following our line of thought,And, secondly, on the plane of dream, where they are entirely different. go from the psychical existence which is merely 'acted,' to that which is exclusively 'dreamed.' In other words, let us place ourselves on the base AB of memory (page 211) where all the events of our past life are set out in their smallest details. A consciousness which, detached from action, should thus keep in view the totality of its past, would have no reason to dwell upon one part of this past rather than upon another. In one sense, all its recollections would differ from its present perception, for, if we take them with the multiplicity of their detail, no two memories are ever precisely the same thing. But, in another sense, any memory may be set alongside the present situation: it would be sufficient to neglect in this perception and in this memory just enough detail for similarity alone to appear. Moreover, the moment that the recollection is linked with the perception, a multitude of events contiguous to the memory are thereby fastened to the perception—an indefinite multitude, which is only
