Chap. 5: Faith and Reason
CHAP. 5: FAITH AND REASON
THE RELATION BETWEEN FAITH AND REASON is one of the most basic problems for any thinking believer. Should we accept God's Word, the Bible, by faith, or are there reasons for believing it? Does reason precede faith, or does faith precede reason? Should we believe without reasons? Are there reasons for believing? Should we seek reasons for our faith, or does this diminish the merits of faith? These and many more questions are treated by Aquinas throughout his writings.
The Relation Between Faith and Reason
Aquinas holds that faith and reason are interrelated. Faith uses reason, and reason cannot go it alone without faith. Both are necessary, but each in its own order.
Reason Cannot Produce Faith
Reason accompanies but does not cause faith. "Faith is called a consent without inquiry in so far as the consent of faith, or assent, is not caused by an investigation of the understanding." Faith is produced by God. Commenting on Ephesians 2:8-9, Aquinas contends that "free will is inadequate for the act of faith since the contents of faith are above reason. . . . That a man should believe, therefore, cannot occur from himself unless God gives it."1 Faith is a gift of God; no one can believe without it.
Nonetheless, "this does not prevent the understanding of one who believes from having some discursive thought of comparison about those things which he believes."2 Discursive thought, or reasoning from premises to conclusions, is not the cause of the assent of faith. Nonetheless, such reasoning "can accompany the assent of faith."3 The reason they are parallel but one does not cause the other is that "faith involves will (freedom) and reason doesn't coerce the will."4 That is, a person is free to dissent even though there may be convincing reasons to believe.
In proclaiming Christian truth to others, if the authority of Scripture is not accepted, then appeal can be made to reason. "Thus, against the Jews we are able to argue by means of the Old Testament, while against heretics we are able to argue by means of the New Testament. But Mohammedans and the pagans accept neither the one nor the other." Aquinas concludes that "we must, therefore, have recourse to the natural reason, to which all men are forced to give their assent."5
Some truths of the Christian faith are attainable by human reason: "Such are that God exists, that He is one, and the like. In fact, such truths about God have been proved demonstratively by the philosophers, guided by the light of the natural reason."6
The Uses of Reason in Christian Faith
Aquinas believes that philosophy can be used in sacred teaching in three ways. 7 First, "we can use it to demonstrate the preambles of faith . . . for example, that God exists, that God is one, or similar propositions concerning God or creatures that faith proposes as having been proved in philosophy." Second, "we can use philosophy to make known through certain likenesses what belongs to faith, as Augustine in his book On the Trinity uses many likenesses drawn from the teachings of the philosophers to explain the Trinity. Third, we can use philosophy to oppose what is said against faith, either by showing that these things are false or by showing that they are not necessary."
In brief, human reason can be used to prove natural theology (e.g., the existence and nature of one God), to illustrate supernatural theology (e.g., the Trinity and incarnation), and to refute false theologies (heresies).8
There are two levels of divine truth. In order to make the first kind of divine truth known, we must proceed through demonstrative arguments by which our adversaries may become convinced. Since such arguments are not available for the second kind of divine truth, however, our intention should not be to convince our adversaries by arguments. It should be to answer their arguments against the truth, for, as we have shown, the natural reason cannot be contrary to the truth of faith. The sole way to overcome an adversary of divine truth is from the authority of Scripture—an authority divinely confirmed by miracles. For that which is above the human reason we believe only because God has revealed it. Nevertheless, there are certain likely (probable) arguments that should be adduced in order to make divine truth known.
God's existence is self-evident absolutely (in itself) but not relatively (to us). Hence, it "is necessary for man to receive by faith not only things which are above reason, but also those which can be known by reason." Furthermore, without faith we would lack certitude. "For human reason is very deficient in things concerning God. . . . Consequently, in order that men might have knowledge of God, free of doubt and uncertainty, it was necessary for divine truth to be delivered by them by way of faith, being told to them as it were, by God Himself Who cannot lie."9
Divine Authority as the Basis of Faith
Reason in itself cannot provide the basis for believing in God. It can prove that God exists, but it cannot convince unbelievers to believe in God.10 We may believe (assent without reservation) something that is neither self-evident nor deduced from it (where the intellect is moved) by a movement of the will. This does not mean, however, that reason plays no role prior to belief. We must judge a revelation to be worthy before we believe it. For people will not believe unless they see that something is worthy of belief on the basis of evident signs or the like.11 Indeed, reason inquires about what is to be believed before it believes in it. In Aquinas's words, "faith does not involve a search by natural reason to prove what is believed. But it does involve a form of enquiry unto things by which a person is led to belief, e.g. whether they are spoken by God and confirmed by miracles."12
Demons, for example, are convinced by the evidence that God exists, but it "is not their wills which bring demons to assent to what they are said to believe. Rather, they are forced by the evidence of signs which convince them that what the faithful believe is true." Yet "these signs do not cause the appearance of what is believed so that the demons could on this account be said to see those things which are believed. Therefore, belief is predicated equivocally of men who believe and of demons."13
In order to believe in God one must have the inner testimony of the Holy Spirit. For "one who believes does have a sufficient motive for believing, namely the authority of God's teaching, confirmed by miracles, and—what is greater—the inner inspiration [instinctus] of God inviting him to believe."14 As to voluntary assent in matters of faith, we can look to two types of causes. "One is a cause that persuades from without, for example, a miracle witnessed or a human appeal urging belief. No such cause is enough, however; one man believes and another does not, when both have seen the same miracle, heard the same preaching. Another kind of cause must therefore be present, an inner cause; one that influences a person inwardly to assent to the things of faith." "The assent of faith, which is its principal act, therefore, has as its cause God, moving us inwardly through grace." This "belief is, of course, a matter of the believer's will, but a person's will needs to be prepared by God through his grace in order to be lifted up to what surpasses nature."15
Human Reason Used to Support Faith
Commenting on the use of "reason" in 1 Peter 3:15, Aquinas argues that "human reasoning in support of what we believe may stand in a two-fold relation to the will of the believer. First, as preceding the act of the will, as, for instance, when a man either has not the will, or not a prompt will, to believe, unless he be moved by human reason; and in this way human reasoning diminishes the merit of faith . . . he ought to believe matters of faith, not because of human reasoning, but because of the divine authority." Second, "human reasons may be consequent to the will of the believer. For when a man has a will ready to believe, he loves the truth he believes, he thinks out and takes to heart whatever reasons he can find in support thereof; and in this way, human reasoning does not exclude the merit of faith, but is a sign of greater merit."16
Faith is supported by, although not based on, probable evidence. "Those who place their faith in this truth, however, 'for which the human reason offers no experimental evidence,' do not believe foolishly, as though 'following artificial fables." Rather, "it reveals its own presence, as well as the truth of its teaching and inspiration, by fitting arguments; and in order to confirm those truths that exceed natural knowledge, it gives visible manifestations to works that surpass the ability of all nature." The kind of positive evidence that Aquinas cites as supportive of faith includes things like raising the dead, the conversion of the world to Christianity, and miracles. The negative evidence encompasses arguments against false religions, including their appeal to carnal pleasures, contradictory teachings, fables and falsities, and perversion of Old and New Testament stories.17
How can we be sure when the support for our faith rests on many intermediary (fallible) testimonies? Aquinas responds: "All the intermediaries through which faith comes to us are above suspicion. We believe the prophets and apostles because the Lord has been their witness by performing miracles, as Mark says [16:20]." Furthermore, "we believe the successors of the apostles and prophets only in so far as they tell us those things which the apostles and prophets have left in their writings."18 The Bible alone is the final and infallible authority for our faith (see Chap. 4).
Aquinas distinguishes between two kinds of rational arguments. "Demonstrative, cogent, and intellectual convincing argument cannot lay hold of the truths of faith, though it may neutralize destructive criticism that would render faith untenable." On the other hand, "persuasive reasoning drawn from probabilities . . . does not weaken the merit of faith, for it implies no attempt to convert faith into sight by resolving what is believed into evident first principles."19
The Distinction Between Faith and Reason.
As some, like Francis Schaeffer, have mistakenly argued, Aquinas does not actually separate faith and reason, although he does formally distinguish between them. He believes they are related, but the relationship is not coercive.
Faith Described in Relation to Reason
Human reason does not force faith. If it did, faith would not be a free act. What happens is that "the mind of the one believing settles upon the one side of a question not in virtue of his reason but in virtue of his will. Therefore assent is understood in the definition [of faith] as an act of the mind in so far as the mind is brought to its decision by the will."20
This does not mean that faith is unreasonable. Faith is reason with assent. For "to ponder with assent is, then, distinctive of the believer: this is how his act of belief is set off from all other acts of the mind concerned with the true and the false."21
Faith, then, is defined as "that habit of mind whereby eternal life begins in us and which brings the mind to assent to things that appear not." Faith differs from science in that its object is unseen. Faith also differs from doubt, suspicion, and opinion in that there is evidence to support it.
Aquinas quotes Augustine with approval: "faith is a virtue by which things not seen are believed."22 He declares that "to believe is an act of mind assenting to the divine truth by virtue of the command of the will as this is moved by God through grace; in this the act stands under control of free will and is directed toward God. The act of faith is, therefore, meritorious. That is, to say one is rewarded for believing in what he does not see. There is no merit in believing what can be seen, since there is no faith involved; it can be seen. The scientist [i.e., philosopher] is impelled to assent by force of a conclusive proof. Thus the assent is not meritorious."23
Faith is an act of mind and will. Aquinas writes: "We have determined that belief is an act of the intellect under the impetus of the will moving it to assent; belief thus issues from both mind and will, each of which, as has been shown, is of its nature perfectible by the training of habit. If an act of faith is to be completely good, then, habits must necessarily be present in both mind and will."24 That is, we cannot be saved unless we are willing to do something with our faith. Saving faith will produce good works.
The Meritorious Nature of Faith
Faith is meritorious because it involves the will to believe.25 It "depends on the will according to its very nature. It is for this reason that to believe can be meritorious, and that faith . . . is a virtue for the theologian."26 "For in science and opinion [probable arguments] there is no inclination because of the will, but only because of reason."27 But "no act can be meritorious unless it is voluntary, as has been said."28
Aquinas believes that Hebrews 11:1 is a good definition of faith, for it not merely describes what faith does but what it is. He sees in it the three essentials of a good definition:
First, from the fact that it mentions all the principles on which the nature of faith depends . . . [namely, the will, the object (good) which moves will, etc.]. The second . . . is that through it we can distinguish faith from everything else, namely, of those things which appear not (as opposed to science and understanding). The third [is] . . . that . . . the whole definition or some part must be put in other words, namely, "substance of things hoped for."29
The Formal Distinction between Faith and Reason
Although Aquinas does not actually separate faith and reason, he does distinguish them formally. We cannot both know and believe the same thing at the same time. For "whatever things we know with scientific knowledge properly so called we know by reducing them to first principles which are naturally present to the understanding. All scientific knowledge terminates in the sight of a thing which is present [whereas faith is always in something absent]. Hence, it is impossible to have faith and scientific knowledge about the same thing."30
The object of faith is above the senses and understanding. "Consequently, the object of faith is that which is absent from our understanding." As Augustine said, we believe that which is absent, but we see that which is present.31 So we cannot prove and believe the same thing. For "all science [philosophical knowledge] is derived from self-evident and therefore seen principles. . . . Now, . . . it is impossible that one and the same thing should be believed and seen by the same person." This does means "that a thing which is an object of vision or science for one, is believed by another."32 It does not mean that one and the same person can have both faith and proof of one and the same object. If one sees it, then he does not believe it on the testimony of others. And if he believes it on the testimony of another, then he does not see (know) it for himself.
Likewise, one cannot have "opinion" (probable knowledge) and "science" (certain knowledge) about the same object. As Aquinas notes, it does not seem possible for a person simultaneously to have scientific knowledge and opinion about the same thing, for opinion includes a fear that the other part [of the contradiction] is true, and scientific knowledge excludes such fear. Similarly, it is impossible to have faith and scientific knowledge about the same thing.
This fear that the opposite may be true, however, does not apply to matters of faith. For faith brings with it a greater certitude than does reason.33
If the existence of God can be proved by reason and if what is known by reason cannot also be a matter of faith, then why is belief in God proposed in the creed? Aquinas responds that not all of us are capable of demonstrating-God's existence. "We do not say that the proposition, God is one, in so far as it is proved by demonstration, is an article of faith, but something presupposed before the articles. For the knowledge of faith presupposes natural knowledge, just as grace presupposes nature."34
Reason, however, can only go so far. The act of believing depends on the understanding and will. This act cannot be perfect unless the will is made perfect by love and the understanding by faith. Since love is the perfection of the will, faith is formed and perfected by love.35
Not only is love necessary to perfect faith, but grace is necessary to produce it. "Now, grace is the first [i.e., remote] perfection of the virtues, but charity is their proximate perfection."36
The Limitations of Reason
Contrary to a popular opinion, Aquinas does not believe that human reason is without limitations. In fact, he offers many arguments why reason is insufficient and revelation is needed.37
Reasons for Revelation
Following the famous Jewish philosopher Moses Maimonides,38 Aquinas sets forth five reasons why we must first believe what we may later be able to provide good evidence for.
The first reason is the depth and subtlety of these objects of knowledge which are farthest removed from the senses. . . . The second reason is the weakness of human understanding when it begins to operate. The third is the number of things needed for a conclusive proof of these. A man can learn them only after a long time. The fourth reason is the disinclination for scientific investigation which some men have because they lack the proper temperament. The fifth is the need of engaging in other occupations to provide the necessities of life.
From this it is clear that "if it were necessary to use a strict demonstration as the only way to reach a knowledge of the things which we must know about God, very few could ever construct such a demonstration and even these could do it only after a long time." And "from this it is evident that the provision of the way of faith, which gives all easy access to salvation at any time, is beneficial to man."
To summarize, human reason is inadequate and divine revelation is essential because of: (1) the depth and subtlety of the object [God], who is far from being an ordinary sense object; (2) the weakness of human intellect in its initial operations; (3) the length of time required to learn the things needed for a conclusive proof; (4) the fact that some people lack proper personality to engage in rigorous philosophical pursuit; and (5) the lack of time for philosophy beyond pursuit of the necessities of life.39
Aquinas explains in some detail why divine revelation is needed. First, "few men would possess the knowledge of God. . . . [1] Some do not have the physical disposition for such work. . . . [2] Others are cut off from pursuing this truth by the necessities imposed upon them by their daily lives. . . . [3] Finally, there are some who are cut off by indolence.
"The second awkward effect is that those who would come to discover the above mentioned truth would barely reach it after a great deal of time. The reasons are several. [1] There is the profundity of this truth. . . . [2] Then, there are many things that must be presupposed, as we said. [3] There is also the fact that, in youth, when the soul is swayed by the various movements of the passions, it is not in a suitable state for the knowledge of such lofty truth. . . .”
"The third awkward effect is this. The investigation of the human intellect for the most part has falsity present within it, [a] and this is due partly to the weakness of our intellect in judgment, [b] and partly to the admixture of images. . . . [c] Furthermore, with the many truths that are demonstrated, there sometimes is mingled something that is false, which is not demonstrated but rather asserted on the basis of some probable or sophistical argument. . . . That is why it was necessary that the unshakable certitude and pure truth concerning divine things should be presented to men by way of faith."40 In short, human reason is limited by nature, circumstances, and operation. Thus, for certitude in divine things faith is necessary.
The Effect of Sin on the Mind
Another widely held but mistaken view is that Aquinas believes the mind is finite but not fallen. On the contrary, he clearly states that the mind falls far short when it comes to the things of God. For "the searching of natural reason does not fill mankind's need to know even those divine realities which reason could prove. Belief in them is not, therefore, superfluous."41 Aquinas asserts emphatically that human reason is very deficient in things concerning God. A sign of this is that philosophers, in their inquiry into human affairs by natural investigation, have fallen into many errors, and have disagreed among themselves. And consequently, in order that men might have knowledge of God, free of doubt and uncertainty, it was necessary for divine truths to be delivered to them by way of faith, being told to them as it were, by God himself Who cannot lie.42
As a result of the noetic effects of sin, grace is needed. Thus we must say that for the knowledge of any truth, man needs divine assistance so that his intellect may be moved by God to actualize itself. He does not, however, need a new light, supplementing his natural light, in order to know truth in all cases, but only in certain cases which transcend natural knowledge. And yet by his grace God sometimes miraculously instructs some men about things which can be known by natural reason, just as he sometimes does miraculously what nature can do. . . . But the human intellect cannot know more profound intelligible realities unless it is perfected by a stronger light, say the light of faith or prophecy; and this is called the light of grace, in as much as it supplements nature.43
Aquinas concludes that "if for something to be in our power means that we can do it without the help of grace, then we are bound to many things that are not within our power without healing grace—for example to love God or neighbor." Further, "the same is true of believing in the articles of faith. But with the help of grace we do have this power. As Augustine says, to whomever this help is given by God it is given in mercy; to whomever it is denied, it is denied in justice, namely because of previous sin, even if only original sin."44
Aquinas does not believe, however, that sin has completely destroyed our rational ability. Rather, he insists that "sin cannot destroy man's rationality altogether, for then he would no longer be capable of sin."45 He believes in the Fall of mankind and inherited sin called "original sin." He spoke of the inevitability to sin for fallen human beings, but he also held that by God’s grace each sin in particular could be resisted. He wrote: "but I the state of corrupted nature man needs grace to heal his nature in order that he may entirely abstain from sin" (ST 1a.109.8). As pervasive as sin is in mankind, "The capital [most] of human nature diminished by sin is the natural inclination to virtue instinctive in man as a rational being…. Now sin cannot destroy man’s rationality altogether, for then he would no longer be capable of sin" (ST1a-2ae.85.1). He adds, "But sin does not strike at the root, sine it does not diminish nature itself; what it does is to block the ability [ibid.] from reaching its end; the disability consists in the interposition of a barrier. Thus, there can be an infinite lessening of virtue, for always another layer can be added, as when man piles sin on sin. Yet the instinct for right action always remains radically intact" (ST1a-2e.85.2). In brief, sin cannot be so great on human nature so that it destroys the human ability to sin. Sin cannot erase the image of God; it can only efface it.
Like Augustine, Thomas held that "the man who misuses free will destroys both himself and it" (Aquinas, OP, Q. 6, Objection 23). So, "the sinner has lost free will so far as concerns freedom from fault and misery, but not so far as concerns freedom from compulsion" (Aquinas, OP, Q. 6, Reply 23).
Things above Reason
Not only is faith necessary because of human depravity, but also because some things simply fall beyond the power of reason. Pasnau correctly notes that "Aquinas also believes that certain truths about God’s nature are beyond the scope of natural reason. He says plain, for example, that "some truths about God exceed every capacity of human reason (SCG I.3.4/14)." (Pasnau, The Philosophy of Aquinas, 82). However, by "beyond reason" Aquinas does not mean what is contrary to reason, but simply what cannot be comprehended by reason. They are the "things which are beyond the comprehension of reason, and so to this extent seem to contradict reason, although they do not really oppose it. In a similar way, to an unlettered person it seems contrary to reason to say that the sun is larger than the earth. . . . However, these appear reasonable to those who are educated.46
"Beyond reason" does not mean unreasonable or even without all reason. For "faith . . . is said to surpass reason, not because there is no act of reason in faith, but because reasoning about faith cannot lead to the sight of those things which are matters of faith."47
We must have faith when the light of grace is stronger than the light of nature. For "although the divinely infused light is more powerful than natural light, in our present state we do not share it perfectly, but imperfectly." Therefore, "because of this defective participation, through that infused light itself we are not brought to the vision of those things for the knowledge of which it was given us. But we will have it in heaven when we share that light perfectly and in the light of God we will see light."48
Faith, then, surpasses reason. For "some truths about God exceed all the ability of the human reason. Such is the truth that God is triune." But "there are some truths which the natural reason also is able to reach. Such are that God exists, that he is one, and the like. In fact such truths about God have been proved demonstratively by the philosophers, guided by the light of the natural reason."49
Of course, the ineffable essence of God cannot be known by human reason. "For the human intellect is not able to reach a comprehension of the divine substance through its natural powers." The reason for this is that "in the present life, the intellect depends on the senses for the origin of knowledge. . . . Now, sensible things cannot lead the human intellect to the point of seeing in them the nature of the divine substance; for sensible things are effects that fall short of the power of their cause."50
Just because we may have no reasons for things that go "beyond reason" does not mean these are not rational. "For everything which must be believed, if it is not self-evident, there is an argument which is not only probable but necessary, yet our diligence may not uncover that argument."51 Hence, "for us, the arguments for matters of faith are unknown, although they are known to God and to the blessed who have vision and not faith about these things."52
While human reason cannot attain to the things of faith, it is the preface to it. For even though "philosophical truths cannot be opposed to truths of faith, they fall short indeed yet they also admit common analogies; and some moreover are fore-shadowings, for nature is the preface of grace."53
Faith and Reason
Reason before
Faith in God
Reason during
Faith in God
Reason after
Faith in God
1. Proves that God exists (preamble of faith)
1. Never basis or cause of faith
1. Never as basis of faith (authority is basis of faith)
2. Disproves nontheisms (alternatives to faith)
2. May accompany or parallel faith
But in support of faith by
3. Shows consistency of Christianity (vs. attacks on faith)
(Consent is caused by mind)
(Consent is caused by will)
Reasoning--
Reasoning--
Reasoning--
1. About faith, not to faith in God
1. In the act of faith in God
1. In support of faith (not as a basis of faith in God)
2. To faith that God is
2. About faith in God (not for faith in God)
2. And for faith in God
3.
And for faith that
God exists
3. And basis for faith that God exists
"Above reason" can have two meanings. The phrase can mean "above reason absolutely" (i.e., above human intellectual capacity). For example, it is impossible to have knowledge of the Trinity by human reason apart from special revelation. We believe in the triune God only on the basis of his own testimony. "Above reason" can also mean "above reason not absolutely" (i.e., not completely above human intellectual capacity). For example, we can have philosophical proofs for a statement like "God exists."54
Faith, then, does not oppose reason. For "although the truth of the Christian faith which we have discussed surpasses the capacity of the reason, nevertheless that truth that the human reason is naturally endowed to know cannot be opposed to the truth of the Christian faith."55
Faith, Reason, and Certitude
Aquinas distinguishes four levels of certainty and uncertainty: doubt, suspicion, opinion, and certitude.56 It is noteworthy to observe that if we could reason as the basis of faith, then faith would not be a free act; it would be consent caused by the mind.
Aquinas's view of the relation of faith and reason is a unique blend of the positive elements of both rationalism and fideism, of presuppositionalism and evidentialism. He stresses the need for reason before, during, and after believing. Even the mysteries of faith are not irrational. On the other hand, he does not believe that reason alone can bring us to faith in God. This is accomplished only by the grace of God. Indeed, faith can never be based on reason. At best it can only be supported by reason. Thus, reason and evidence are never coercive of faith. There is always room for unbelievers not to believe in God, even though a believer can construct a valid proof that God exists. For reason can be used to demonstrate that God exists, but it can never in itself persuade someone to believe in God. Only God can do this, working by his grace in and through free choice.
Aquinas's distinctions are eminently relevant to the contemporary discussion between rationalists and fideists or between evidentialists and presuppositionalists. With regard to belief that God exists, Aquinas sides with the evidentialist. But with respect to belief in God, he agrees with the fideist. This unique synthesis of faith and reason provides further reasons to believe that old Aquinas should not be forgotten.