The author takes as his point of departure David Harvey's original formulation of territorial social justice and recognises the subsequent emergence of a politics of difference as central to the discourse of justice. The contemporary preoccupation with difference is problematised. The argument proceeds from recognition of morally significant aspects of human sameness, through the identification of human needs and the case for associated rights, to an egalitarian conception of social justice. The Earths uneven resource endowment, a traditional disciplinary preoccupation, is viewed as morally arbitrary and hence an aspect of difference to be transcended. The paper concludes with some observations on moral motivation, asking why we should actively endorse social justice.