This essay explores the role of commensuration – the mechanisms that render equitable and negotiable different orders of value – in the production of society and history. While equilibration, standardization and conversion are implicated in most theories of money and commodification, their nature as social processes has not been adequately specified, above all in the construction of universalizing ideologies and modernist political and economic regimes. We pursue these processes in relation to one African theatre, examining the ways in which different regimes of value, brought up against one another in the encounter between the southern Tswana peoples and European colonizers, became the subject of both conflict and complex mediation. Cows, coin and contracts – which had the capacity to construct and negate difference – soon were invested here with magical qualities. But colonized peoples were also sensitive to the capacity of such currencies to enable or impede convertibility and the forms of abstraction and incorporation they permit. Which is why, in South Africa and elsewhere, those currencies often became metonymic of the contestations of value on which colonial struggles, tout court, were played out.