One might compare the relation of the ego to the id with that between a rider and his horse. The horse provides the locomotor energy, and the rider has the prerogative of determining the goal and of guiding the movements of his powerful mount towards it. But all too often in the relations between the ego and the id we find a picture of the less ideal situation in which the rider is obliged to guide his horse in the direction in which it itself wants to go.
Sigmund FreudAnother technique for fending off suffering is the employment of the displacements of libido which our mental apparatus permits of and through which its function gains so much in flexibility. The task here is that of shifting the instinctual aims in such a way that they cannot come up against frustration from the external world.
Sigmund Freud