The symbolic interpretation of causes by means of the energic standpoint is necessary for the differentiation of the psyche, since unless the facts are symbolically interpreted, the causes remain immutable substances which go on operating continuously, as in the case of Freud's old trauma theory. Cause alone does not make development possible. For the psyche the reductio ad causam is the very reverse of development; it binds the libido to the elementary facts. From the standpoint of rationalism this is all that can be desired, but from the standpoint of the psyche it is lifeless and comfortless boredom -- though it should never be forgotten that for many people it is absolutely necessary to keep their libido close to the basic facts. But, in so far as this requirement is fulfilled, the psyche cannot always remain on this level but must go on developing, the causes transforming themselves into means to an end, into symbolical expressions for the way that lies ahead. The exclusive importance of the cause, i.e., its energic value, thus disappears and emerges again in the symbol, whose power of attraction represents the equivalent quantum of libido. The energic value of a cause is never abolished by positing an arbitrary and rational goal: that is always a makeshift. Psychic development cannot be accomplished by intention and will alone; it needs the attraction of the symbol, whose value quantum exceeds that of the cause. But the formation of a symbol cannot take place until the mind has dwelt long enough on the elementary facts, that is to say until the inner or outer necessities of the life-process have brought about a transformation of energy.... In civilized man the rationalism of consciousness, otherwise so useful to him, proves to be a most formidable obstacle to the frictionless transformation of energy. Reason, always seeking to avoid what to it is an unbearable antinomy, takes its stand exclusively on one side or the other, and convulsively seeks to hold fast to the values it has once chosen. It will continue to do this so long as human reason passes for an "immutable substance," thereby precluding any symbolical view of itself. But reason is only relative, and eventually checks itself in its own antinomies. It too is only a means to an end, a symbolical expression for a transitional stage in the path of development.