The chief difficulty in the case is to find the connection between the last act of reason and the first act of faith, the medium of transit from the natural to the supernatural. The Catholic doctrine teaches that the act of faith is above the natural power of the human mind. It is strictly supernatural, and possible only by the aid of supernatural grace. Yet it is a rational act, for the virtue of faith is seated in the intellect as its subject, according to the teaching of St. Thomas. It is justifiable and explicable on rational grounds, and even required by right reason. The truths of revelation are not only objectively certain, but the intellect has a subjective certitude of them which is absolute, and excludes all suspicion or fear of the contrary. Now, then, unless we adopt the hypothesis that we have lost our natural capacity for discerning divine truth, by the fall, and are merely restored by divine grace to the natural use of reason, there are several very perplexing questions on this point which press for an answer. Rejecting this hypothesis of the total corruption of reason, which will hereafter be proved to be false and absurd, how can faith give the mind absolute certitude of the truth of its object, when that truth is neither self-evident nor demonstrable to reason from its own self-evident principles? Given, that the intellect has this certitude, how is it that we cannot attain to it by the natural operation of reason? Once more, what is the evidence of the fact of revelation to ordinary minds? Is it a demonstration founded on the arguments for credibility? If so, how are they capable of comprehending them, and what are they to do before they have gone through with the process of examination? If not, how have they a rational and certain ground for the judgment that God has really revealed the truths of Christianity? Suppose now the fact of revelation established, and that the mind apprehends that God requires its assent to certain truths on the virtue of his own veracity. The veracity of God being apprehended as one logical premiss, and the revelation of certain truths as another, can reason draw the certain conclusion that the truth of these propositions is necessarily contained in the veracity of God or not? If it can, why is not the mind capable of giving them the firm, unwavering [{586}] assent of faith by its own natural power, without the aid of grace? If not, how is it that the assent of the intellect to the truth of revealed propositions does not always necessarily contain in it a metaphysical doubt or a judgment that the contrary is more or less probable, or at least possible? If it is said that the will, inclined by the grace of God, determines to adhere positively to the proposed revelation as true, what is meant by this? Does the will merely determine to act practically as if these proposed truths were evident, in spite of the lesser probability of the contrary? Then the assent of the intellect is merely a judgment that revelation is probably true, and that it is safest to follow it, which does not satisfy the demand of faith. For faith excludes all fear or suspicion that the articles of faith may possibly be false. Does the will force the intellect to judge that those propositions are certain which it apprehends only as probable? How is this possible? The will is a blind faculty, which is directed by the intellect, "Nil volitum nisi prius cognitum." [Footnote 128] There is no act of will without a previous act of knowledge. The will can not lawfully determine the intellect to give any stronger assent to a proposition than the evidence warrants. [Footnote 129] In a word, it is difficult to show how the intellect has an absolute certitude of the object of faith, without representing the object of faith as coincident with the object of knowledge, or the intuitive idea of reason, and thus naturally apprehensible. It is also difficult to show that faith is not coincident with knowledge, and thus to bring out the conception of its supernaturalness, without destroying the connection between faith and reason, subverting its rational basis, and representing the grace of faith as either restoring a destroyed faculty or adding a new one to the soul, whose object is completely invisible and unintelligible to the human understanding before it is elevated to the supernatural state. The difficulty lies, however, merely in a defective statement, or a defective apprehension of the statement of the Catholic doctrine, and not in the doctrine itself. In order to make this plain, it will be necessary to make one or two preliminary remarks concerning certitude and probability.
[Footnote 128: Nothing is willed unless previously known.]
[Footnote 129: This is the statement of an objection, not a proposition affirmed by the author.]
There is first, a metaphysical certitude excluding all possibility to the contrary. Such is the certitude of mathematical truths. Such also is the certitude of self-evident and demonstrable truths of every kind. The sphere of this kind of certitude is diminished or extended accordingly as the mind has before it a greater or lesser number of truths of this order. Some of these truths present themselves to every mind so immediately and irresistibly that it cannot help regarding them just as they are, and thus seeing their truth. For instance, that two and two make four. Others require the mind to be in a certain state of aptitude for seeing them as they are, and to make an effort to bring them before it. There are some truths self-evident or demonstrably certain to some minds which are not so to others; yet these truths have all an intrinsic, metaphysical certitude which reason as such is capable of apprehending, and the failure of reason to apprehend them is due in individual cases merely to the defective operation of reason in the particular subject. The operation of reason can never be altogether deficient while it acts at all, for it acts only while contemplating its object or primitive idea. But its operation can be partially defective, inasmuch as the primitive idea or objective truth may be imperfectly brought into the reflective consciousness. And thus the intellect in individuals may fail to apprehend truths which can be demonstrated with metaphysical certitude, and which the intellect infallibly judges to be absolutely certain in [{587}] those individuals who are capable of making a right judgment. In this operation of apprehending metaphysical truths there is no criterion taken from experience, or from the concurrent assent of all men, but the truth shines with its own intrinsic light, and reason judges by its inherent infallibility.
Next to metaphysical certitude comes moral demonstration, resulting from an accumulation of probabilities so great that no probability which can prudently be allowed any weight is left to the other side, but merely a metaphysical possibility. For instance, the Copernican theory.
Then comes moral certainty in a wider sense; where there is probable evidence on one side without any prudent reason to the contrary, but not such a complete knowledge of all the facts as to warrant the positive judgment that there is really no probability on the other side. This kind of certainty warrants a prudent, positive judgment, and furnishes a safe practical motive for action; but it varies indefinitely according as the data on which the judgment is based are more or less complete, and the importance of the case is greater or less.
Then come the grades of probability, where there are reasons balancing each other on both sides, which the mind must weigh and estimate.
To apply these principles to the question in hand.
First, we affirm that the being and attributes of God are apprehended with a metaphysical certitude. Second, that the motives of credibility proving the Christian revelation are apprehended, when that Revelation is sufficiently proposed, with a varying degree of probability, according to varying circumstances in which the mind may be placed, but capable of being increased to the highest kind of moral demonstration. Third, that the logical conclusion which reason can draw from these two premises, although hypothetically necessary and a perfect demonstration--that is, a necessary deduction from the veracity of God, on the supposition that he has really made the revelation--is really not above the order of probability, on account of the second premiss. It is not above the order of probability, although, as we have already argued, it is capable of being brought to a moral demonstration by such an accumulation of proofs within that order, that reason is bound to judge that the opposite is altogether destitute of probability.
From this it appears, both how far reason with its own principles can go in denying, and how far it can go in assenting to revealed truth. We see, first, how it is, that the truth of revelation does not compel the assent of all minds by an overwhelming and irresistible evidence. The first premiss, which affirms the being of God, although undeniable and indubitable in its ultimate idea, may be in its distinct conception, so far denied or doubted by those whose reason is perverted by their own fault, or their misfortune, as to destroy all basis for a revelation. The second premiss, much more, may be partially or completely swept away, by plausible explanations of its component probabilities in detail. And thus, revelation may be denied. The influence of the will on the judgment which is made by the mind on the revealed truth is explicable in this relation, and must be taken into the account. It is certain that the moral dispositions by which voluntary acts are biased, bias also the judgment. The self-determining power of the will which decides positively which of its different inclinations to follow, controls the judgment as well as the volition. This is an indirect control, which is exerted, not by imperiously commanding the judgment in a capricious manner to make a blind, irrational decision, but by turning it toward the consideration of that side toward which the volition or choice is inclined. This influence and control of volition over judgment increases as we descend in the order of truth from primary and self-evident principles, and diminishes as we [{588}] approach to them. In the case of truth which is morally or metaphysically demonstrable, its control is exerted by turning the intellect partially away from the consideration of the truth and hindering it from giving it that attention which is necessary, in order to its apprehension. In the case of divine revelation, various passions, prejudices, interests, or at least intellectual impediments to a right operation of reason, act powerfully upon a multitude of minds in such a way, that the mirror of the soul is too much obscured to receive the image of truth.