Summa Theologica I, q. 1: The Nature and Extent of Sacred Doctrine
Article 2. Whether sacred doctrine is a science?
Objection 1It seems that sacred doctrine is not a science. For every science proceeds from self-evident principles. But sacred doctrine proceeds from articles of faith which are not self-evident, since their truth is not admitted by all: "For all men have not faith" (2 Thess. 3:2). Therefore sacred doctrine is not a science.
Objection 2Further, no science deals with individual facts. But this sacred science treats of individual facts, such as the deeds of Abraham, Isaac and Jacob and such like. Therefore sacred doctrine is not a science.
On the contraryAugustine says (De Trin. xiv, 1) "to this science alone belongs that whereby saving faith is begotten, nourished, protected and strengthened." But this can be said of no science except sacred doctrine. Therefore sacred doctrine is a science.
I answer thatSacred doctrine is a science. We must bear in mind that there are two kinds of sciences. There are some which proceed from a principle known by the natural light of intelligence, such as arithmetic and geometry and the like. There are some which proceed from principles known by the light of a higher science: thus the science of perspective proceeds from principles established by geometry, and music from principles established by arithmetic. So it is that sacred doctrine is a science because it proceeds from principles established by the light of a higher science, namely, the science of God and the blessed. Hence, just as the musician accepts on authority the principles taught him by the mathematician, so sacred science is established on principles revealed by God.
Reply to Objection 1The principles of any science are either in themselves self-evident, or reducible to the conclusions of a higher science; and such, as we have said, are the principles of sacred doctrine.
Reply to Objection 2Individual facts are treated of in sacred doctrine, not because it is concerned with them principally, but they are introduced rather both as examples to be followed in our lives (as in moral sciences) and in order to establish the authority of those men through whom the divine revelation, on which this sacred scripture or doctrine is based, has come down to us.
Article 3. Whether sacred doctrine is one science?
Objection 1It seems that sacred doctrine is not one science; for according to the Philosopher (Poster. i) "that science is one which treats only of one class of subjects." But the creator and the creature, both of whom are treated of in sacred doctrine, cannot be grouped together under one class of subjects. Therefore sacred doctrine is not one science.
Objection 2Further, in sacred doctrine we treat of angels, corporeal creatures and human morality. But these belong to separate philosophical sciences. Therefore sacred doctrine cannot be one science.
On the contraryHoly Scripture speaks of it as one science: "Wisdom gave him the knowledge [scientiam] of holy things" (Wis. 10:10).
I answer thatSacred doctrine is one science. The unity of a faculty or habit is to be gauged by its object, not indeed, in its material aspect, but as regards the precise formality under which it is an object. For example, man, ass, stone agree in the one precise formality of being colored; and color is the formal object of sight. Therefore, because Sacred Scripture considers things precisely under the formality of being divinely revealed, whatever has been divinely revealed possesses the one precise formality of the object of this science; and therefore is included under sacred doctrine as under one science.
Reply to Objection 1Sacred doctrine does not treat of God and creatures equally, but of God primarily, and of creatures only so far as they are referable to God as their beginning or end. Hence the unity of this science is not impaired.
Reply to Objection 2Nothing prevents inferior faculties or habits from being differentiated by something which falls under a higher faculty or habit as well; because the higher faculty or habit regards the object in its more universal formality, as the object of the "common sense" is whatever affects the senses, including, therefore, whatever is visible or audible. Hence the "common sense," although one faculty, extends to all the objects of the five senses. Similarly, objects which are the subject-matter of different philosophical sciences can yet be treated of by this one single sacred science under one aspect precisely so far as they can be included in revelation. So that in this way, sacred doctrine bears, as it were, the stamp of the divine science which is one and simple, yet extends to everything.