Abstract
In this article I provide a Thomistic truthmaker principle. Although Aquinas himself never provides a truthmaker principle, he does say things that show he thought many truths require truthmakers, or, in other terms, that truths have an ontological grounding. That truths are somehow grounded or explained by reality is an important aspect of Thomistic thought. The principle I provide could be affirmed by someone with Thomistic tendencies : it is consistent with Aquinas' thought and makes sense of some peculiar aspects of his writings. In what follows, I will argue that a Thomistic truthmaker principle should require all truths about being to have a truthmaker at any time that they are about (and I will explain what these two restrictions mean).