Main reviews briefly the contributions to understanding of perception and ego function of Freud, Schilder, Hartmann, Kris, and Loewenstein, Glover, Fairbairn, and Klein. He states, for example, that Hartmann's ideas shed light on conflict-free secondary process thought but on the origins of perception do not go beyond Freud's formulation that the system perception-conscious, which is part of the ego, has the prime function of perception. All the theories discussed rely on the thesis that perception of objects begins with instinct driven proprioceptor perceptions. Main does not discount these intrinsic developmental tendencies, but emphasizes that maturation is far from being automatic; it is always the outcome of, not the lack of, special environmental circumstances, primarily the various activities involved in mothering. The perceptive mother aids the growth not only of the ego but even of perception itself. Perhaps the genesis of perception in man is conditional to appropriate introjections of the perceptive abilities of the person doing the mothering.