Aristotle's thought about economic matters has been a seminal influence. It was the backbone of medieval thinking about commerce, and the basis of analyses of money into this century. But its interpretation has become chaotic. Economists claim Aristotle as the father of economics, while classical scholars hold that Aristotle did no economics at all, only ethics.This book argues, contrary to the prevailing view, that Aristotle does develop a coherent theory of value, wealth, exchange, and money, which is strongly backed up by his metaphysics. But its metaphysical foundation makes it impossible to assimilate the theory to Neo-Classical economics or any other kind of economic thinking, and it remains an ethical theory. On Aristotelian metaphysical principles, ethics and economics are competitors over the same ground, as rival sources of reasons for decision-making in the public realm, and they cannot be reconciled.