On universals: The scholastic realism of John Duns Scotus and Charles Sanders Peirce

Date of Award




Degree Name

Doctor of Philosophy (Ph.D.)

First Committee Member

Susan Haack, Committee Chair


The problem of universals is shown to be the problem of trying to determine what kinds of things concepts are, the connection concepts have with the world at large, and what effect this has on claims to knowledge of the world as it is. The problem is traced from its origin in Plato through the works of Aristotle, Alexander of Aphrodisias, Porphyry, Boethius, and Avicenna. The realist position that claims universals as real is contrasted with the nominalist one which says that only individuals exist and are real. Since knowledge of the world is acquired through concepts (universals) the nominalist is in the uncomfortable position of having to admit to not knowing the world as it really is. Scotus' attempt at trying to resolve the problem is evaluated. Peirce's declaration that he is even more of a realist than Scotus at first seems inconsistent because of nominalistic and idealist elements in Peirce's own theory, but after understanding his relation to Scotus and Scotus' relation to his predecessors, Peirce's position can be seen as a coherent, even if not completely defensible, whole. However, it is recommended that he be called a "realicist" instead so as to differentiate him from the more common varieties of realists.



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