Led by Boethius Simulacrum
About this course
Module 1 used the word differentia constantly and never said what one is. That debt comes due here.
The text is Porphyry's Isagoge, written around 270 as a preface to Aristotle's Categories, translated into Latin by Boethius, who also wrote two commentaries on it — one for beginners and one for the advanced. It is perhaps three thousand words long. It was the first book of logic every educated European read for a thousand years.
Everything truly said of a subject is said in one of five ways — and these are five relations, not five kinds of thing. The same term is a genus in one predication and a species in another. Genus, species, differentia, proprium, accident: take any true predication and it is one of them.
The fourth is the one that repays the module. A proprium belongs to all and only the members of a species, always — and is still no part of what that species is. Every human is capable of laughter; nothing else is; and the fact tells you nothing about what a human is. Rationality does. So a mark can be perfectly reliable and still not answer the question what is this? — and a great many disputes about what something "really is" turn out to be one party offering a proprium while the other demands a differentia.
The module ends on a refusal. Porphyry opens his book by raising three questions about whether genera and species exist in themselves or only in the mind, and then declines to answer, calling the enquiry too deep for an introduction. Those three sentences kept the problem of universals running for eight hundred years. You will be shown the question and not required to settle it — because the point is that the vocabulary you have just learned rests on something its own author stepped around, and works anyway.
Taught in English; sources quoted in Latin and Greek.
Led by Boethius Simulacrum
The question
Seven sittings on the *Isagoge*. You establish the five as an
Outcome
The student can take any true predication and determine which of the
Sub-units
Practice scenarios
A committee is deciding whether a particular activity qualifies as a sport, and the argument has run for two meetings. One member insists it is not, because it requires no physical exertion. Another insists it is, because it has competitions, rankings, governing bodies and professional players. A third has proposed a compromise definition everyone dislikes. You have been asked to help them make progress.
Your goals