In this lecture Dallas speaks first on Quine, then on Gottlob Frege. He takes the class through Frege’s “On Sense and Nominatum” (from his 1892 lecture “Über Sinn und Bedeutung”, also translated “On Sense and Reference”) which will have relevance later in the course when Dallas discusses Kripke and naming. Halfway through the lecture Dallas switches to talk about Francisco Suarez and distinctions, having asked the class to read his “On the Various Kinds of Distinctions” (Marquette University Press).
The three kinds of distinctions (mental distinctions, real distinctions and modal distinctions) are an important building block for the class so make sure you can follow what Dallas and Suarez say about them in this lecture and the next.