I gave a talk for the Food for Thought seminar for the Notre Dame philosophy department.
The topic concerned definite descriptions, particularly the semantics that might be given when one extends first-order logic to include the iota operator, by which $℩x\varphi(x)$ means “the $x$ such that $\varphi(x)$.” There are a variety of natural ways to define the semantics of iota assertions in a model, and we discussed the advantages and disadvantages of each approach. We concentrated on what I call the strong semantics, the weak semantics, and the natural semantics, respectively. Ultimately, I argue for a deflationary perspective on the debate, as each of the semantics is conservative over the base language, with no iota operator, with no new expressive power. In this sense, I argue, the choice of one semantics over another is purely a matter of convenience or ease of expressibility, as all of the notions are expressible without definite descriptions at all.
My lecture notes are below.
