The unification of psychology has proven a perennial problem. Vygotsky's solution was to reverse the usual predominance of theory over practice, making practice the 'supreme judge' of truth. Matusov's goal appears to be a more modest one: the integration of cultural-historical and sociocultural Vygotskians into a harmonious 'family'. Analysing the aporias of Matusov's text, I argue that what unites these two groups of Vygotsky's heirs is a common commitment to liberation from oppression and the promotion of equality. Vygotskians thus take their place in a far larger movement of psychologists who share these commitments and apply them not just to theory but to the practice of research, politics and pedagogy. Hence Matusov's argument, despite its paradoxes, ellipses and internal contradictions, has a far larger reach than he implies, but one that turns out to be quite in keeping with Vygotsky's initial proposals for a unified psychology.