Date of Award

Spring 2-24-2011

Degree Type

Closed Thesis

Degree Name

Master of Arts (MA)



First Advisor

Andrew I. Cohen

Second Advisor

Christie Hartley

Third Advisor

William Edmundson

Fourth Advisor

Andrew Altman


Richard Joyce claims sincerely uttering moral claims necessarily commits the moral claimant to endorsing false beliefs regarding the predication of nonexistent (non-)natural moral properties. For Joyce, any proposition containing a subject, x, saddled with the predicate “…is moral”[1] will have a truth-value of ‘false’, so long as the predicate fails to refer to anything real in the world. Furthermore, given the philosophical community’s present state of epistemic ignorance, we lack sufficient evidence to justify our endorsement of the existence of (non-)natural moral properties purportedly capable of serving as truth-makers for moral claims. My thesis offers a defense of Joyce’s moral error theory against two different lines of criticisms proffered by Russ Shafer-Landau—one conceptual in nature, and the other ontological. I argue that available evidence compels the informed agnostic about moral truth to suspend judgment on the matter, if not endorse Joyce’s stronger thesis that all moral claims are false.