For Aristotle, a just political community has to find similarity in difference and foster habits of reciprocity. Conventionally, speech and law have been seen to fulfill this role. This article reconstructs Aristotle’s conception of currency as a political institution of reciprocal justice. By placing Aristotle’s treatment of reciprocity in the context of the ancient politics of money, currency emerges not merely as a medium of economic exchange but also potentially as a bond of civic reciprocity, a measure of justice, and (...) an institution of ethical deliberation. Reconstructing this account of currency in analogy to law recovers the hopes Aristotle placed in currency as a necessary institution particular to the polis as a self-governing political community striving for justice. If currency was a foundational institution, it was also always insufficient, likely imperfect, and possibly tragic. Turned into a tool for the accumulation of wealth for its own sake, currency becomes unjust and a serious threat to any political community. Aristotelian currency can fail precisely because it contains an important moment of ethical deliberation. This political significance of currency challenges accounts of the ancient world as bifurcated between oikos and polis and encourages contemporary political theorists to think of money as a constitutional project that can play an important role in improving reciprocity across society. (shrink)