Research Workshop: "Persistent Self-Predication Problems in Plato's Forms"

Cody Spjut (Cal State Long Beach)

Friday, December 1st, 2023 (12:10-2:00 PM) Baker Science (180) Room 0112



In Plato’s Parmenides, Socrates and Parmenides debate about the nature of the Forms. Socrates implicitly characterizes the Forms as entities which possess the very properties they are said to exemplify (call this characterization the “self-predication principle”). For example, the Form "Beauty" is itself beautiful. Parmenides objects to this characterization of the Forms, arguing that it leads to an infinite regress in which Forms endlessly participate in themselves (to put his point very roughly).

Many philosophers since Plato have attempted to make sense of the self-predication principle. Aristotle argued that self-predication renders the Theory of Forms philosophically inert. More recently, Gregory Vlastos attempted to defend the Theory of Forms from such arguments. Nevertheless, some problems resulting from self-predication seem to persist. The goal of my research is to examine self-predication problems which have most recently been shown to threaten Plato’s Theory of Forms. After doing so, I evaluate a unique solution proposed in Anna Marmodoro’s recent book Forms and Structure in Plato’s Metaphysics. I conclude that while Marmodoro's interpretation is a valuable contribution to the debate, she fails to consider alternative interpretations which raise problems that she does not adequately address.


Cody Spjut completed his Bachelor’s degree in philosophy at Cal Poly, San Luis Obispo in Spring 2021. During his time at Cal Poly, he had interests in studying Plato’s Republic, as well as “non-canonical” figures and women in the history of philosophy.

Cody is currently completing his Master’s degree in philosophy at California State University, Long Beach. His Master’s studies are focused on Plato’s philosophy and Ancient Greek history and culture more generally. He is writing three research papers in place of a Master’s thesis: (1) Self-Predication in Plato’s Forms, (2) Plato’s Penal Theory in the Gorgias, and (3) The Consequences of Lockean Akrasia.


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