Loci Classici

Loci classici is the Latin plural of locus classicus, 'a classical place'. In scholarly usage it refers to the standard passages that any serious discussion of a topic returns to — the handful of sentences from Plato, Aristotle, Augustine, Shakespeare, or a similarly foundational figure that have become, over time, the reference points every subsequent argument on the subject touches.

For any topic that has been discussed for more than a few centuries, there is a small, stable set of loci classici. Discussions of the good life return, again and again, to a few passages in Aristotle's Nicomachean Ethics. Discussions of justice return to the opening of Plato's Republic and to a few lines of Ulpian. Discussions of mercy return to Portia's speech in The Merchant of Venice. The passages have earned their status by being simultaneously precise, memorable, and open enough to admit a range of interpretations.

Knowing the loci classici of a subject is one of the most useful shortcuts in learning it. Not because the passages settle the question — they usually do not — but because they define the room in which the question has historically been argued. A newcomer who can find their way to the four or five great passages on their topic has, in an afternoon, oriented themselves in a conversation that took a century to build.

The related concept is the 'commonplace' — a passage traditionally memorised, quoted, and reused. Loci classici are the commonplaces of scholarship. In Renaissance schooling, students were taught them explicitly, and were expected to be able to recognise, cite, and rebut them by rote.

For a modern reader: when approaching a new subject, do not begin with the latest paper. Begin by asking a specialist for the three or four passages the field always returns to. Read those first, slowly, with a notebook. Everything you read afterwards will fit into a shape those passages have already outlined.