Got 24 theses?

Proh dolor! I’m collecting items for the eventual posting of another 10 reasons I am not a Thomist, and came across this item/issue this morning. As a student of Aquinas in the post-neo-scholastic period I of course knew about the existence of the famous “24 Thomistic theses,” asserted by Pius X in 1914 to be the central theses of the philosophical teaching of Aquinas, especially in the metaphysical realm. My teachers, Fr James Weisheipl and Lawrence Dewan—the former a member of River Forest Thomism, and the latter a clarification, he would argue, of the Toronto Existential Thomistic school—both had referred to the theses now and again, and how the philosophical system “Thomism” was thought to be staked-out by these discrete tenets. Neither required us to think that our learning would fail to be ad normas sancti Thomae, however, should we fail to memorize the theses.

Fine. But it dawned on me today, as I was hunting through various websites, that I’m not sure that I could enunciate even one of those theses! Materially I could, of course, in the sense that I could probably name this or that Thomistic philosophical teaching, and provide some explanation and that, as it happens, a doctrine I mention might be among the 24 theses. But formally speaking, if you were to ask me something like, “what are the ____ (give number here) essential theses of Thomistic metaphysics?” I’d swing and miss.

Not to worry. Today I found some handy resources, in the form of Hugh McDonald’s Latin-based list and translation of the theses, and another rendering of the theses with footnotes to places in Thomas’s works where the thesis is found or substantiated. So at least I know what the theses are now.

Failure to know them certainly does not make someone a non-Thomist, but since I try to know as much as I can about the history of Thomas’s teaching (and its antecedents), it’s clear that I’ve got to do more study on this part of the history of Thomism.


Mark Johnson

Mark Johnson is an associate professor of Theology at Marquette University, and founded on Squarespace in November of 2004. He studied with James Weisheipl, Leonard Boyle, Walter Principe, and Lawrence Dewan, at the Pontifical Institute of Mediaeval Studies (Toronto, Canada).