In contrast with Edmund Husserl and Max Scheler, Edith Stein proposes a distinct object of study for psychology, the psyche, implicitly thereby criticising the fusion of phenomenology and psychology which can be found in both Husserl and Scheler. In Psychic Causality, she conducts a constitutional analysis of the psyche as a unity constituted from all acts in which life power plays a role. Life power presents in vigour and tiredness, in the positive or negative impact of emotions, and is distinct from motivation in that it cannot be “felt into” or followed; it seems to be restored when I am at rest and spent in activity; and it can be studied, as analogous to a battery, in the economy of mental life. Life power also manifests in our personal, institutional, and animal relations, and thereby contributes to the formation of community, society, and mass. As electricity can power several machines on the same network, so psychic energy can be shared between several persons, in a number of essentially different ways. This diversity distinguishes the different forms of sociality, such that it is key to understanding how the individual contributes to intersubjective constitution. This chapter attempts to show how the social dimension of the psyche gives rise to the idea of social causality and argues that this is what is studied by the social sciences. In doing this, it is providing an account of the object of the social sciences that is compatible with that of the Schutzian tradition.