Compendium Theologiae Dogmaticae Tomus I: De Christo Legato Divino, De Ecclesia Christi, De Fontibus Theologicis

Cf. S. Thomas, S. th. I, q. 1; his commentators, such as Gregorius de Valentia; Kleutgen, Theologie der Vorzeit tract. 5; J. Didiot, Logique surnaturelle subjective, Paris 1894.

1. Theology, as the very name indicates, is concerned with God, though not in such a way that God is its sole object, but in such a way that whatever is treated in theology is either God himself or something else insofar as it is referred to God as first principle and ultimate end. Therefore God is called the subject of theology, because in theology all things are predicated of God either directly or indirectly. In this it agrees with that part of philosophy which is commonly called natural theology or theodicy, from which it differs essentially by reason of its formal object.

2. Since in philosophy God is considered insofar as he is known from principles that are objectively and subjectively natural, the theology of which we are speaking here pertains to the supernatural order. Its objective principle, from which it proceeds, is divine revelation, once made to the prophets and apostles and handed down to the Church; its subjective principle, however, is reason illumined by divine faith. Accordingly, the formal object of theology is truth demonstrable from public divine revelation. The relation to God as subject makes things pertain to theology in the ontological order; the relation to public revelation as formal object makes it possible for things in the logical order to be known theologically. Thus theology is defined as the science of things that are demonstrable about God from revelation.

God, then, is considered in theology in two ways. a) God as God is the subject or, as some put it, the formal object of theology: that which theology treats, or that about which it speaks; b) God, insofar as by revelation he renders truths knowable theologically, is the principle and source of theology. Revelation is called the formal object by means of which theology knows. Theological knowability itself, resting on divine revelation, is sometimes called the formal aspect under which; but this designation is also applied to the supernatural illumination of the intellect that theology presupposes. Accordingly, different writers are accustomed to use these terms in different ways. For the present, therefore, it is simpler to retain only that distinction between the subject and the formal object of theology.

3. Is theology a science in the proper sense of the word? In science two things must be distinguished: knowledge of the principles from which one argues, and the certainty of the demonstrations drawn from those principles. Knowledge of principles, in turn, is derived either from their intrinsic evidence (immediate or mediate) or from authority. But the first principles of theology are not intrinsically evident to human beings; rather, they are made known by divine authority. Therefore, if one says it belongs to the notion of science that it proceed from intrinsically evident principles, one must deny that theology is a science in the strict sense. So Scotus says in the prologue to Book I of the Sententiae, n. 26 ff., and many others agree with him. If, on the other hand, one says that science is that which draws certain conclusions from known and certain principles, then one will regard theology as a science. So St. Thomas says in the first part of the Summa theologiae, q. 1, a. 2, and very many theologians agree with him.

This latter manner of speaking seems preferable, and theology must be called a science. For what constitutes the specific character of science considered subjectively—certainty acquired through reasoning—is found in theology, indeed more perfectly than in the other sciences, because it is founded on firmer principles. Science considered objectively is a body of certain propositions, connected with one another and gathered into a single system. Theology is such a body. The unity of theological science is evident from the unity of its subject and formal object.

Since theological science depends on divine science, it is commonly called a subalternated science (a subordinate science), while divine science is called a subalternating science with respect to theology. Theology is also commonly defined as the science of faith. In this definition, faith is taken either objectively, insofar as it is the complex of revealed truths, or subjectively, because faith is the principle from which theology proceeds, just as natural reason is the subjective principle of philosophy, which is therefore called the science of reason. Supernatural theology and natural theology, then, differ in species.

4. Theology differs from faith a) in its matter: in faith, this is all and only revealed truth, whereas in theology it also includes many other truths inferred by reasoning from revealed truths; b) in its form, because faith embraces its object on account of the authority of God revealing, whereas theology does so on account of scientific demonstration. «I believe in order to understand» (St. Anselm, Cur Deus homo 1, 2); c) in certainty, which in theology is of a lower order than in faith, since theology does not, as faith does, rest solely on divine authority, but also mingles in human considerations and conclusions.

Nevertheless, theology is intimately connected with faith, because the revealed truths from which it proceeds are held by faith alone, and because it uses reason illumined by the light of faith. Hence the habit of theological science, although acquired in itself, may nevertheless be called radically supernatural, since «sacred doctrine is, as it were, a kind of imprint of divine knowledge» (St. Thomas 1, q. 1, a. 3 ad 2).

Hence it is clear how great is the dignity of this science: its principles are from God supernaturally revealing; it treats of God, who is knowable supernaturally; it is directed to God as its supernatural end; and it is a kind of foretaste of the beatific vision. Consequently, theology is also wisdom in a singular way. For «sacred doctrine most properly treats of God insofar as he is the highest cause, because it treats not only of what can be known through creatures, but also of what is known to God alone about himself and communicated to others through revelation. Hence sacred doctrine is called wisdom in the highest degree» (St. Thomas 1, q. 1, a. 6).