Abstract

introduced the concept of effective demand in the nascent science of economics; his discussions of astronomy were acute enough to raise Duhem’s interest. Neither are Buridan’s credentials as a nominalist in doubt, although investigation into his precise relation to William of Ockham continues: he rejected all abstract entities, whether universals, common natures, the complexe significabile, or types above and beyond tokens; for Buridan, every thing which exists is a concrete individual. His anti-realism included an epistemological component as well, for Buridan maintained that the source of all knowledge is experience.