Rom Harré criticizes critical realism for ascribing causal powers to social structures, arguing that it is human individuals, and not social structures, that possess causal powers, and that a false conception of structural causation undermines the emancipatory potential of critical realism. I argue that an interpretation of the category of process as the spatio-temporalization of the category of structure, which underpins much evolutionary theory, provides the conceptual tools to explain how the critical realist transformational model of social activity can escape (...) from Harré’s criticism, leading to a general conception of social development within which various types of evolutionary processes can be identified as particular cases. I then argue that Tony Lawson’s PVRS model provides an evolutionary perspective that enables the conceptualization of coercive power as selective pressure. (shrink)