The author defines passivity as a relative absence of activity and as one phase of biological adaptation, a phase that seems to demand an easy, flexible capacity for the utilization of both the active and passive components of the instinctual drives. Passivity can be healthy or unhealthy for the effective functioning of the psyche. Healthy passivity facilitates adaptation, unhealthy passivity reduces it. Passivity is both a component of an instinctual drive and a defense mechanism of the ego. It is greatest in the early, oral phase of ego and libido development. Fixation at that phase results in lifelong conditioning to use passivity as defense.

Hart also discusses and illustrates the relation of passivity to femininity, regression, and masochism.