Apologeticae sive Theologiae Fundamentalis, Tomus I: Demonstratio Christiana

It is twofold: verbal and real.

(a) Verbal notion. Theology (θεός, λόγος) is etymologically a speech and discourse about God. For the Greek word λόγος designates both the external word, the word of the mouth, i.e., the speech or utterance about God, and the internal word, the word of the mind, i.e., the reasoning or knowledge about God.

In usage, however, it came about that this word signified different things at different times.

Among the pagans, all those were called theologians who discoursed about the gods and their relations to the world, whether poets, or philosophers, or priests of idols. Hence Varro¹ distinguishes, following the received custom, a threefold kind of theology among the pagan peoples: "the mythical (or fabulous), which the poets chiefly use; the physical (or natural), which the philosophers use; the civil (religious), which the peoples use."

Christians of the earlier centuries assigned the name of theology in the strict sense to the doctrine about God one in essence and triune in persons. Indeed, especially in the times of Arianism and Macedonianism, the investigation concerning the divinity of the Word and of the Holy Spirit was called theology. Hence St. John the Evangelist and St. Gregory of Nazianzus, because they had taught the divinity of the Son more clearly, were meaningfully called theologians. Every doctrine that dealt not strictly with God considered in Himself, but with our relation to God (concerning creation, redemption, the whole order of salvation), the holy Fathers called the economy.

The scholastics of the Middle Ages, finally extending the name more broadly, began to call theology every revealed doctrine, both that which is about God and that which is about creatures inasmuch as they are referred to God. This way of speaking is still in force. These things being premised, it readily appears:

(b) Real notion. Theology is the science of those things which are knowable, by the light of revelation, about God and about things related to God; or: the science of God and divine things from revelation.

By these words there is set forth the genus of the thing to be defined: "Theology is a science"; the species: "of God and divine things"; and the individual difference: "from revelation."

Theology is a science (an intellectual habit). For three things belong to the nature of science: principles, method, system. Namely, principles, i.e., fundamental and altogether certain truths from which scientific knowledge proceeds and on which it rests; method, i.e., the logical development and proof of the truths which depend on the principles; and system, by which it comes about that the deduced and proven truths are not detached members, but are so harmoniously disposed and joined that they constitute one body, one scientific organism.

Now no one will deny that theology is endowed with scientific method and system; the dispute is only about the principles. The nominalists, Vásquez, and the modern rationalists deny theology its scientific character on the ground that its principles are not evident, i.e., not known per se and intrinsically. Nevertheless, the proper characteristic of a science is not the evidence of its principles but their certainty, since certainty is the end of science, not evidence. But theological principles, although not evident, are nonetheless most certain. For all of theology rests on revelation, whose existence is proven certain by rational arguments in apologetics and which, moreover, possesses supernatural and infallible certainty from faith. Therefore theology deserves to be called a science with greater right than all other sciences.

…of God and divine things. By these words there is set forth the material object of theology, i.e., everything that is attained or known in this science. It is, however, twofold: the primary object is God Himself, or the sum of truths that can be known about God one and triune; the secondary object, moreover, is all creatures, considered not indeed in themselves, but inasmuch as they have God as their origin and last end.

Therefore, since created things are treated in theology only in relation to God, the subject of theology is God alone: "All things are treated in sacred doctrine under the aspect of God, either because they are God Himself, or because they have an order to God as to their principle and end. Hence it follows that God is truly the subject of this science."²

…from revelation. These words indicate the formal object of theology, i.e., the special aspect under which this science attains or knows its material object. This formality of theology is revelation. The theologian considers all and each of the theological matters under the light of revelation. The principle from which theological knowledge is drawn is objective revelation (the truths contained in Sacred Scripture and divine Tradition and proposed to us by the Church); the principle, however, by which theological knowledge is acquired is subjectivated revelation (reason enlightened by faith).

Hence theology differs from theodicy. Theodicy treats of God insofar as He is knowable by mere reason from the natural order of the world; theology, however, insofar as He is knowable by reason enlightened by faith from revelation. Although therefore they agree with respect to the primary material object, they differ specifically in formal object. A fortiori, theology is distinguished from all other sciences. For all of them are occupied with created matters alone, and investigate them solely by the light of natural reason. Hence they are also called natural or profane sciences.

(c) Corollaries. 1°. On the various denominations of theology. From what has been said we readily understand why theology is often called: the supernatural habit, sacred doctrine, Sacred Scripture, the sacred Page, the science of faith. It is called the supernatural habit because, although it is not infused supernaturally but is acquired by natural effort, nonetheless the habit of theology is radically supernatural, since it is learned by reason enlightened by faith and is nourished from the sources of revelation. It is called sacred doctrine because it learns divine things with God Himself teaching through revelation, "so that sacred doctrine is like a certain impression of divine knowledge."³ It is called Sacred Scripture or the Page by denomination from the more important part, because in the time of the holy Fathers and in the Middle Ages the text of Sacred Scripture was read above all in the theological schools and was explained with the help of the holy Fathers, theologians, and philosophers.⁴ Theology is therefore called the science of faith because it cultivates faith taken objectively (the revealed truths) and is governed subjectively by the principle of faith (the light of revelation). For the rest, the second corollary is to be noted:

2°. On the relation between theology and faith: 1°. Theology cannot be identified (converted) with faith. For faith is a habit infused by God disposing one to assent to revealed truths on account of the authority of God revealing, and therefore it differs from theology, which is a habit acquired by human study, on four counts: α) In matter; for theology embraces not only the revealed truths, as faith does, but also the conclusions deduced from them and the controversies arising from them. β) In motive; for faith assents to revealed truths on account of the sole authority of God revealing, whereas theology admits its propositions on account of the goodness of the inference or reasoning by force of which they are drawn from revealed principles. γ) In method; for faith indeed neither argues nor reasons, but adheres to revealed truths by a simple assent of the mind, whereas theology scientifically deduces, proves, and defends its propositions from revelation. δ) In certainty; for the certainty of faith is supreme and absolute, because by faith we hold only those things which, and insofar as they, are revealed by God; the certainty of theology, however, is inferior and relative, because many things are argued theologically which are not formally revealed by God, and all things are affirmed insofar as they are understood by human reason.

2°. Theology cannot be separated from faith. For there is no science where one does not have certainty of a thing discussed and established. Therefore a theologian who denies the revealed truths with an incredulous mind, or at least calls them into doubt, does not possess theological science. Hence one versed in sacred doctrine who falls into heresy indeed retains the notions he acquired by theological study; he can also treat of theological matters materially; nevertheless his theology is reduced to a merely opinionative habit. Moreover, anyone lacking faith is usually affected with such blindness regarding divine things that he becomes incapable of seeing even the most evident theological conclusions, just as a defective eye becomes incapable of adequately apprehending the most brilliant colors. Hence the scholastics rightly say that there is no true theology among heretics. To this the Anselmian maxim looks: "I believe in order to understand": whoever wishes to acquire the theological science of the revealed truths must begin from humble faith, and the more humbly he believes, the more apt he becomes to investigate the revealed truths deeply.