ABSTRACT
Let us imagine ourselves in the situation of an almost entirely helpless living organism, as yet unorientated in the world, which is receiving stimuli in its nervous substance. This organism will very soon be in a position to make a first distinction and a first orientation. On the one hand, it will be aware of stimuli which can be avoided by muscular action (flight); these it ascribes to an external world. On the other hand, it will also be aware of stimuli against which such action is of no avail and whose character of constant pressure persists in spite of it; these stimuli are the signs of an internal world, the evidence of instinctual needs. The perceptual substance of the living organism will thus have found in the efficacy of its muscular activity a basis for distinguishing between an ‘outside’ and an ‘inside’.
