242 PSYCHOTHERAPY : SCIENTIFIC AND RELIGIOUS chap.
action, would discover personality for the most part in the profoundest depths of the unconscious as a system of libidinous wishes perpetually striving against the repressing forces, both conscious and unconscious, of social convention and the super-ego.
Pleasure is found in the mere satisfaction of instinctive desires, and distress or pain occurs when their satisfaction is thwarted. The pleasure-principle is directly related to the sex instinct; in which is contained the quantity of psychic energy with which an individual is endowed at the start of his earthly career. To this quantity of psychic energy Freud gave the name libido, to indicate the energy derived from the sexual instincts. It is the energy drive that is responsible for such diversified activities as love-making, chivahy, physical aggression, the creative urge of the artist, the yearning of the adolescent and so on. In short, it is all the manifestations that spring from the energy of the love emotion. Freud, tracing the transformation of the love-energy in the development of the emotional lives of his patients from childhood onward, saw the libido undergo manifold changes.
At the moment of birth the child is without a mental life as we know it. It has a body that is as yet uncoordinated, and some instinctual ways of using that body. Its first interest is expressed through the mouth ; its first contact the mother's breast, its first emotion the pleasure of imbibing warm milk. Its first desires achieved, the infant sinks back, supremely satisfied, into a state of lack of desire, and sleeps. As the infant grows, it discovers its own body, and the pleasure of playing with the lips, the mouth, the tongue. The cooing and chuckling laugh of the swaddled infant arises from delight with the flow of air over the tongue and lips. Muscular activity itself is another source of pleasure for the infant. The opportunities for enjoy-