Ever since its formulation in Hume’s (1739) A Treatise of Human Nature, philosophers have had to contend with the idea of an inferential barrier between non-ethical (‘is’) propositions and ethical (‘ought’) propositions. Much of my work focuses on providing a more logically rigorous characterization of the is-ought thesis, describing Prior’s Paradox in terms of a dilemma and its two horns, and identifying the implications of this paradox for the is-ought thesis. An evaluation of various formal defenses to Prior’s Paradox on behalf of Hume will be made. In addition, I will also introduce the term ‘deontic irrelevance’ to describe Prior-style ‘is’-‘ought’ inferences, draw connections between these formal defenses and other informal defenses of Hume’s inferential barrier, and attempt to shed more light on the nature of ethical argumentation and its uses in general.
Melvin Chen, Nanyang Technological University, Singapore