This paper revisits Aquinas's understanding of theology as a science based on a participation in the divine scientia. Our modern presuppositions (in terms of “autonomous” reason and philosophy as a discipline utterly separate from theology) often appear to render Aquinas's claims implausible. In this contribution it is argued that (a) all sciences are fiduciary in the broad sense (with the exception of those that rely on principles per se nota) and (b) that first principles can only be accepted or rejected, but not refuted or demonstrated within the relevant discipline. From this, two conclusions can be drawn: first, despite its reliance on revelation theology's case is, therefore, not as peculiar as modern readers might initially assume: every discipline operates with key assumptions it simply accepts. Secondly, given the role of first principles, to characterise Aquinas's account of the assent of faith as fideist or voluntarist is beside the point, for you can only accept or reject first principles. The contribution ends by suggesting that assent to the articles of faith is not an extraneous acquiescence in assertions of divine authority either, as a reading of the first question of the Secunda Secundae makes clear. Indeed, the paper hints that we should not read the first question of the Prima Pars without engaging with the first questions of the Secunda Secundae.