These lectures On Law were delivered in the academic session of 1533–4 as part of Vitoria's day-to-day teaching of Aquinas' Summa, which he was then working through for the third time in his career (the full cycle took roughly seven years). It was to be the last time he would cover ST I-II; a fourth cycle, begun in 1539, had to be abandoned to substitutes by Christmas 1540 because of illness.

The extracts translated here consist of lectiones 121 – 9 and 136 – 7 (from the session's total of 154 lectures). The Spanish academic year began on the Monday after St Luke's Day, 15 October; these lectiones would thus have been delivered around Wliitsuntide of 1534, roughly at the beginning of our summer term. Officially, Vitoria should have been covering the university's set text for theology, Lombard's Sentences, but he preferred Aquinas. This was not the only liberty Vitoria took; the copyist of our MS notes that he omitted the ‘easy’ questions 25–49 altogether, ‘so as to get through the text by the end of term’ (‘ut possemus hoc anno finem imponere toti 1e 2e, fol. 29v). In the lectures translated below Vitoria omits some of Aquinas' articles, or dismisses them with a phrase.

The lectiones survive only in students' reportata. The ones translated here are taken from the anonymous Vatican MS Ottob. 1000.