This lecture is, obviously, about categories. Dallas begins with Aristotle and working through a selection from his Categories. Listen well to how Dallas divides Aristotle’s categories because it will be the basis of what is to come. At around 25:00 he mentions Aristotle’s view of “secondary substance,” that is, how, on Aristotle’s view, things hang together and have the powers they do, namely through qualities. The alternative, typical today, is something called atomism. It is a topic that will be explored later as well and is worth making a note of.
At around 35:15, Dallas names the two concepts of substance present in Aristotle, that he doesn’t necessarily reconcile. 1) That which has the parts and properties, what Aristotle calls “primary substance.” 2) That which accounts for the unity of parts and properties, what Aristotle calls “secondary substance,” that is, its essence.
At the end (52:30), Dallas seems to be reading from a handout he wrote probably one titled “Concerning Categories” (not currently available digitally).