Scholastica commentaria in Primam Partem Summae Theologicae

It is argued first for the negative side by the first argument of St. Thomas: every science properly so called must proceed from principles known per se: but theology does not proceed from principles known per se, therefore it is not a science. But if you reply, with St. Thomas, that it suffices for the character of a science that its principles be known by the light of a higher science; it is urged against this. For if someone were now to take the principles of optics, which are otherwise conclusions of geometry, and assented to them only on the authority of the master of geometry who hands them down, that man would not have a science properly of optics; therefore neither do we properly have the science of theology. The antecedent is proved. For the whole discourse of the disciple is founded on the human faith of the master. And it is confirmed. If the principles of our theology are not evident to us, it follows that our theology is only a science of consequences, not of conclusions, and hence does not differ from logic. The consequence is proved. For in this consequence: every man is risible, Christ is a man, therefore Christ is risible, the major is evident to the physicist, the minor belongs immediately to faith; therefore the theologian's office will be only to judge that the consequence is good.

It is argued second: a heretic who errs in one article of faith can syllogize from the other articles. And yet a syllogism of this kind in a heretic does not generate science, therefore neither in a Catholic. The minor is admitted by all. The consequence is proved. For those principles from which the heretic proceeds are also known per se in the light of the science of the Blessed; therefore if this suffices for our theology to be a science, that too will be a science, or neither. And it is confirmed, and I suppose, that a Catholic theologian falls into one error only, e.g. that there is no purgatory, or that the souls of the saints do not see God until the day of judgment. Then this theologian does not immediately lose the acquired habit of theology; therefore if in that man that habit is not a science, neither was it a science before in the same Catholic.

It is argued third: if a conclusion which is called theological is to be deduced from the principles of faith, this must be done either by an evident consequence or by a probable one. If by an evident one, then the conclusion is also of faith, e.g. Christ is risible. But if by a non-evident one; then the conclusion will for the most part be a probable opinion, therefore theology is not properly a science.

It is argued fourth: a science properly so called must be concerned with necessary conclusions and from necessary principles: but very many of the principles of our theology are contingent, e.g. that the Word was made flesh, that he suffered in the flesh, that Antichrist will be born, and other similar things: to which nevertheless we assent immediately through faith; therefore the conclusions which are gathered from such principles are not necessary, and consequently there is no science properly so called concerning them.

FOR the solution of this difficulty note that although Cajetan said in the preceding article that by the name of sacred doctrine St. Thomas did not understand faith determinately, or theology determinately, but took it indifferently for revealed doctrine either immediately, such as faith is, or mediately, such as theology is; nevertheless now in this article sacred doctrine is verified not of faith, but of the doctrine which inclines to the assent of the conclusions which are deduced from the principles of faith. For faith is related to this doctrine as the habit of first principles is to the natural sciences

Note secondly that Aristotle in 1 Posterior Analytics defined science with the utmost rigor, so that scarcely can any demonstration be brought into the middle for the form of that exemplar, except in mathematics. Just as Cicero also described the supreme orator, such as you will never find. But he will be a good orator who has come for the most part to the prototype. Wherefore Aristotle himself also taught, book 1 Ethics, ch. 3, that it is foolish to demand in every science and matter demonstrations equal in certainty and clarity. For this is the mark of an undisciplined mind. But in each science one must require demonstrations more or less exact according to the subject matter. For there is greater certainty and clarity in mathematics than in physics, inasmuch as physics, which is concerned with mobile being, shows its principles from the effect. But mathematics, since it deals with quantity, which is also plain to the senses, although it abstracts from sensible matter and from things subject to motions, nevertheless in the account of whole and part is most manifest to the intellect, and therefore the mathematical principles, Every whole is greater than its part, and, Things equal to one third thing are equal to one another, and similar ones, are most manifest to the intellect: since the terms of these principles are known to all. But in metaphysics, on account of the excessive abstraction of the object from intelligible matter, not all the principles are known per se to us. Whence very many metaphysical demonstrations are with difficulty comprehended by us. But indeed in moral matters, according to the Aristotelian precepts, a demonstration can scarcely be made, unless one adds that the demonstration is according to the subject matter. And nevertheless disciplines of this kind are called and are sciences.