Article 2: “Whether Sacred Doctrine is a Science?”
Having demonstrated the necessity of sacred doctrine, it remains for Aquinas to tell us what kind of thing sacred doctrine is. The first thing he says, in the second article of the first question, is that it is a science, by which he means an ordered body of knowledge of causes. Sacred scripture provides us with the first principles or premises of our science, and the job of sacred doctrine, accordingly, is to provide the conclusions which may be demonstrated or deductively inferred from these principles. This is to do theology as though it were geometry—very Aristotelian in methodology (see Aristotle’s Posterior Analytics). These premises taught in sacred scripture, however, are unique in that they have to be taken on faith—Thomas calls them the “articles of faith” —yet these premises are actually demonstrated or taken from an even higher science, which he calls the “science of God and the blessed.” To have this kind of knowledge, however, you need to be either God or one of the blessed dead.