The Necessity for Revelation:
A Primer on Summa Contra Gentiles 1, Chaps. 1-9

Alfred J. Freddoso
University of Notre Dame


A. Philosophy in general

Philosophy is the love of wisdom. Wisdom in the unqualified sense is a systematic understanding of and ordering of "the truth which is the origin of all truth, viz., the truth that pertains to the first principle of being for all things" (Chapter 1). The One who is wise in the preeminent sense is He who orders the whole universe and to whose intellect the universe conforms [truth in the primary sense], whereas human beings are wise to the extent that our understanding is conformed to the universe as so ordered [truth in the secondary sense].

In Chapter 9 St. Thomas divides our knowledge of the first principle of being into three parts:

    a. knowledge of God in Himself,
    b. knowledge of the procession of creatures from God, and
    c. knowledge of the ordering of creatures to God as an end.

So knowing God as the first principle of being involves, in the final analysis, knowing all creatures insofar as they proceed from Him as their efficient cause and are ordered to Him as their end or final cause. The above topics define the first three books of the Summa Contra Gentiles, whereas the fourth book consists of the refutation of errors with respect to peculiarly Christian doctrines that are not even in principle accessible to non-believers.

The pursuit of wisdom (studium sapientiae) is identified by St. Thomas on biblical grounds with the search for God and is simultaneously identified with what Aristotle calls First Philosophy or Metaphysics, the study of being qua being. This twofold identification constitutes an important step in St. Thomas's attempt to integrate the Greek philosophers' quest for wisdom, which he takes to express a natural human desire for systematic understanding of the world and our place in it, with the sort of quest for divine knowledge that the Christian is embarked on. What St. Thomas believes is that the Christian quest is continuous with and perfective of the Greek philosophers' pursuit of wisdom. That is, the pursuit of wisdom by the pagan philosophers finds its true culmination in the theological virtue of faith and the concomitant gifts of the Holy Spirit that Christians call wisdom, understanding, and knowledge.


B. The fruits of philosophy in general

According to St. Thomas, philosophy, taken to be the pursuit of as evident a knowlege of God as is possible for us, is "more perfect, sublime, useful, and joyful" than any other human endeavor:

    a. It is more perfect [or, better, more perfective] because the limited grasp of divine truth possible in this life is a foretaste of that evident and face-to-face knowledge of God which is, according to Christian revelation, the principal constituent of ultimate human fulfillment.

    b. It is more sublime because it is through wisdom that we become most like God and are joined to Him in friendship.

    c. It is more useful because through this wisdom we can order our lives in such a way as to attain the reign of immortality.

    d. And it is more joyful because the possession of wisdom brings no bitterness or tediousness but only gladness and joy.

Truth is central here, and this has two consequences worth noting. First, it follows that the pursuit of wisdom bears the above fruits only if it in fact leads us toward divine truth -- this in opposition to the romantic and ultimately skeptical claim that the search for truth is more important than actually finding the truth. Second, it follows that if two metaphysical worldviews differ from one another, then at most one of them can be true on the points where they differ -- this in opposition to the currently popular view in the discipline of comparative religion that, despite appearances, all comprehensive visions of the world basically say the same thing and are thus equally true.


C. Two ways to understand philosophy

But is such wisdom possible for us? If so, what are the sources of this wisdom? Can we attain to it simply by relying on our natural powers of cognition? Or is more required?

In the middle of a discussion of immortality in Plato's dialogue Phaedo, Socrates's interlocuter Simmias remarks:

    "One should achieve one of these things: learn the truth about these things or find it for oneself, or, if that is impossible, adopt the best and most irrefutable of men's theories, and, borne upon this, sail through the dangers of life as upon a raft, unless someone should make that journey safer and less risky upon a firmer vessel of some divine doctrine."

St. Thomas, of course, believes that we are indeed the beneficiaries of a divine revelation whose main elements are the doctrines of the Trinity, the Creation, the Fall, the Incarnation, the Atonement, the Resurrection, the Church, and the Sacraments. And now the question before him is how this revealed Christian drama is related to what was discovered by the pagan philosophers in the absence of such revelation. Do Christian revelation and pagan philosophy render one another superfluous? That is, are they competitors or are they in some sense complementary?

In Chapter 3 St. Thomas distinguishes two ways in which the truth about the first principles of being is made manifest to us, viz., (i) through divine revelation [and faith in this revelation] and (ii) through natural reason. On this basis we can distinguish two conceptions of philosophy:

    1. The broad conception. This is philosophy understood expansively as the endeavor to articulate and defend a comprehensive metaphysical vision of the world; philosophy so understood is free to, indeed obliged to, draw upon every source of truth available to us as human beings, including both revelation and natural reason, where the latter includes every source of truth distinct from Sacred Scripture and the teachings of the Church.

    2. The narrow conception. In the narrow sense philosophy is the search for wisdom by appeal only to the deliverances of natural reason and not to revelation.

On the narrow conception, philosophy draws its premises from natural reason alone and is thereby set off from theology, which takes revealed propositions as its starting points and tries, within the limits of human finitude, to order and understand them systematically. This distinction between philosophy and theology became pivotal in the thirteenth century when Aristotle's works flooded into the European universities, and since then it has served within Catholic universities as the theoretical foundation for the separation between philosophy and theology departments.  (Whether this separation has been a blessing is another, and fairly complicated, story.  For some reflections on it, see my "Two Roles for Catholic Philosophers".)

St. Thomas singles out this narrower sense of philosophy in part because it helps him clarify what he regards as the proper posture Christians should assume toward secular learning in general and toward secular philosophy in particular. The history of Christianity has been marked by recurrent and bitter disputes over this issue. From the earliest times some Christians (I will dub them 'anti-secularists') have denounced secular 'wisdom' as an adversary of Christianity. They have sternly warned fellow Christians about the pitfalls of syncretism, and they have pointedly asked why, if not because of an obsequious (and typically futile) desire to curry favor with intellectually prestigious unbelievers, a Christian might want to study, say, the books of Aristotle with the same intensity as the books of Sacred Scripture. They recall that when St. Paul preached in Athens, he was ridiculed by the philosophers, who in their pride preferred the wisdom of the world to the wisdom of God (Acts 17:16-34). What, they ask disdainfully, has Jerusalem to do with Athens? Christianity is itself a philosophy or wisdom that competes with secular philosophies and aims to displace them.

Anti-secularists typically spurn efforts to articulate Christian doctrine with the help of conceptual resources borrowed from secular philosophy. An animus against the intrusion of secular philosophy into theology characterizes many of the most important and influential reactionary movements in Church history, e.g., the fourth- and fifth-century resistance to the conciliar definitions of the doctrines of the Incarnation and the Trinity, at least some elements of the thirteenth-century opposition to Aristotle, sixteenth-century Lutheranism's call for a return to the Bible, and twentieth-century Barthian neo-orthodoxy. In addition, anti-secularists tend to repudiate in theory the natural theologian's attempt to show that at least some revealed truths can be established on grounds that unbelievers as such should or at least can accept.


D. The preambles of the faith and the mysteries of the faith

St. Thomas, by contrast, accepts reason and revelation as distinct sources of truth, both emanating from God Himself. In particular, he recognizes a limited autonomy for reason and its standards of rational acceptability. Thus, he has no problem in principle either with natural theology or with the use of strictly philosophical concepts in the theological articulation of Christian doctrines. Indeed, on St. Thomas's view natural reason is, within its own domain, capable of attaining greater intellectual certitude than is faith. However, he insists that "in divine matters reason has its failings," and one of these failings is that reason's domain is more limited than that of faith.

Mindful of the metaphysical achievements of Plato, Aristotle, and their philosophical progeny, St. Thomas asks directly whether reason can serve as an alternate source of the truths revealed to us by God and, more specifically, whether reason can demonstrate such truths by arguments from evident premises. The answer is both yes and no:

    "In those things that we profess about God there are two types of truths. For there are some truths about God that exceed every capacity of human reason, such as that God is [both] three and one. But there are other truths that natural reason is also capable of arriving at, such as that God exists, that there is one God, and others of this sort. Indeed, philosophers, led by the light of natural reason, have proved these truths about God demonstratively" (Chapter 3).

St. Thomas thus divides revealed truths into what he elsewhere calls the mysteries [or: articles] of the faith, which "exceed every capacity of human reason," and the preambles of the faith, which reason can at least in principle establish on its own. In other words, if we are to accept the mysteries of the faith at all, we must accept them on faith, whereas it is at least in principle possible for us even in this life to have evident philosophical knowledge of the preambles of the faith.

At this point, you might expect (or fear) a disquisition on the arguments for God's existence. However, as we shall see in a moment, almost every believer accepts even the preambles on faith. First, though, let's get a bit clearer about the nature of faith.


E. The Nature of Faith

What exactly is it to accept something on faith? What St. Thomas says in other places about the nature of faith as a general cognitive stance can be encapsulated in the following formula:

    Faith (in general) is an intellectual act (habit) by which a person

      (a) gives intellectual assent,
      (b) prompted by the will out of trust,
      (c) for the sake of acquiring some good,
      (d) to propositions that (i) are not themselves evident or intellectually compelling to him, but that (ii) he sees as having been taught as truths by someone who is in a position to know.

If we reflect on the personal relations between children and parents, students and teachers, patients and doctors, colleagues in the workplace and the laboratory, friends, etc., we will begin to understand just how pervasive a role faith in this general sense plays in our ordinary lives. (See Augustine, Confessions 6, chap. 5.)

Using this formula, we can specify distinctively Christian faith as follows:

    Christian faith (in particular) is an intellectual act (habit) by which a person

    (a) gives intellectual assent,
    (b) prompted by the will, as aided by grace, out of trust in God,
    (c) for the sake of acquiring everlasting human fulfillment,
    (d) to propositions (the deposit of faith) that (i) are not themselves evident or intellectually compelling to him, but that (ii) he sees as having been taught as truths by a God who can neither deceive nor be deceived.

Much more could be said here, but it is important to note that because the objects of faith are not intellectually compelling, faith does not, as St. Thomas puts it, "bring the intellect to rest." That is, other things being equal, faith is intellectually inferior to, and intellectually less certain than, evident knowledge. However, St. Thomas claims that faith is often more certain than evident knowledge in the sense that many things we accept on faith are such that we adhere to them more strongly than we do to what is intellectually evident. The main reason is that we trust the epistemic authority in question more strongly than we trust our own judgments on the relevant matters.  Another reason is that these things are often more central to our lives than are evident truths, and so more is at stake. In the case of Christian faith, we have only to reflect on the faith of martyrs to see his point.


F. Some natural questions

In Chapters 3-6 St. Thomas addresses several questions that are immediately prompted by the distinction between the mysteries of the faith and the preambles of the faith:

  • QUESTION 1 (chapter 3): Is it reasonable to believe that there are truths about divine matters which in principle exceed our natural capacities for systematic understanding? Isn't there, after all, an incoherence involved in the idea that we know what we don't know?

    REPLY: "That there are certain truths about God that totally surpass man's ability appears with greatest evidence":

    • 1. Argument from our incapacity to grasp the divine substance (i.e., nature): We cannot in principle comprehend the divine nature, where comprehension includes knowledge of a substance in itself and knowledge of all its possibilities. For all our knowledge begins with that which falls under the senses. But our cognition of God's sensible effects is a cognition of effects which are not "equal to" their cause. So even though what we know of God's sensible effects might be able to lead us to knowledge in the strict sense of some truths about God, we have no reason to believe that God's nature is exhausted by whatever it takes to create our world. (For instance, on the basis of what we know about the created universe, we have no reason to believe that there are three persons in God.)

    • 2. Argument from the gradation of intellects: It is reasonable for a less intelligent person to believe that there are truths grasped by a more intelligent person which he cannot grasp. But the intellect of an angel surpasses any human intellect by a greater distance than that by which any human intellect surpasses any other. (For an angel has cognition of God through a much more perfect effect, viz., his own angelic nature, than any effect through which we have cognition of God.) And the divine intellect exceeds an angelic intellect by a greater distance than that by which an angelic intellect exceeds a human intellect. But even an angel cannot by nature grasp all of the things about God which God himself grasps: "So just as it would be the height of folly for a simple person to assert that what a philosopher proposes is false on the ground that he himself cannot understand it, so (and even more so) it is the acme of stupidity for a man to suspect as false what is divinely revealed through the ministry of the angels simply because it cannot be investigated by reason."

    • 3. Argument from our failure to grasp even those things which we can in principle investigate and grasp: Even with respect to sensible things we realize that we are in ignorance to a great extent, and in most cases we are not able to discover fully the natures of those things. (This argument is just as telling today despite the fact that natural science has advanced far beyond what it was in the days of St. Thomas.) So it is hardly surprising that our intellect is not equipped to comprehend God.

    St. Thomas's conclusion is this: "Therefore it is not the case that everything said about God--even if it cannot be investigated by reason--should be immediately rejected as false, as the Manicheans and other unbelievers thought." Hence, if we are to know God at all well, natural reason will not suffice.

  • QUESTION 2 (chapter 4): Wasn't it pointless for God to reveal truths that natural reason is in principle capable of establishing on its own, i.e., the preambles of the faith such as God's existence and some of the divine attributes?
  • REPLY: If the preambles were not revealed, then three really bad consequences would ensue:

    • 1. Only a few people would have knowledge of the preambles: (a) Some people are by dint of their intellectual endowment incapable of coming to a natural knowledge of the preambles of the faith. No amount of study and studious application would bring them to a knowledge of the preambles. (b) Most people have to tend to the necessities of life and hence do not have enough leisure time to pursue philosophical studies. (Within the Church, too, there are many other important roles to be filled.) (c) Many who have the innate intellectual prerequisites and the possibility of being freed from other duties are nonetheless too indolent for such studies. Much hard study is required and those who are willing to undergo such a regimen are few in number--even though God has implanted in human nature a natural desire for knowledge.

    • 2. Those who did discover the preambles would do so only after a long time -- which is bad because it is important for them to adhere to the truth as soon as possible. This is in part because of the profundity of these truths and of the arguments leading one to knowledge of them, and in part because of the long preparation needed in order to approach these matters with even a modicum of confidence. In addition, the passions of youth get in the way of this long and necessary preparation, as does senility. St. Thomas concludes: "Thus if reason were the only way to come to a knowledge of God, then the human race would remain in the darkest shadows of ignorance. For the cognition of God, which makes human beings especially perfect and good, would come only to a few and to them only after a long time."

    • 3. The chances are great that the knowledge attained would be admixed with error and uncertainty, and this because of the weakness of our intellect. Many would fail to see the truth of those things which have been demonstrated, because they know that many who have been called wise have disagreed with one another and thus accepted falsehoods on important matters. On the other hand, many of the alleged demonstrations probably contain some falsehoods, and so are deserving only of tentative assent. Probably the best we can do is to have a well-grounded opinion that God exists and has certain attributes. At least this much is true: we won't get the adherence of the martyrs just from philosophical studies. St. Thomas concludes: "And so it was necessary that a fixed certitude and pure truth with respect to divine matters be presented to human beings through the way of faith."
  • QUESTION 3 (chapter 5): Is it proper for God to demand that we accept on faith propositions that reason cannot in principle attain to and that thus cannot be made intellectually compelling to us?
  • REPLY: There are several reasons why God might do this:

    • 1. Faith in the mysteries is the beginning of eternal life, and this beginning is necessary if we are to tend with zeal to a form of happiness which exceeds what reason can aspire to here and now. These truths call us to something beyond our present state and so serve as an antidote to pessimism and despair. (Even the pagan philosophers felt impelled to call us to the pursuit of goods beyond those which are obvious to the senses.)

    • 2. Faith in the mysteries makes our knowledge of God more correct, since it reinforces the idea that we do not comprehend God. For otherwise we might tend to forget that we know God truly only when we believe that he is beyond everything that it is possible for a human beings to think of on their own.

    • 3. Faith in the mysteries curbs the presumption of reason and thus serves as an antidote to a rash optimism about our cognitive powers. As St. Thomas puts it: "For there are those who rely on their own abilities to such an extent that they think that they are able to measure the whole nature of things by their own intellects -- so that they judge as true whatever seems true to them and as false whatever what does not seem true to them. So in order that the human mind, liberated from this presumption, might be able to attain to a modest investigation of the truth, it was necessary for God to propose to man things which completely exceed his intellect."

    • 4. These truths give us the greatest delight and keep us from fixing our sights wholly on mortal things. We need this sort of delight in order to keep from falling back into 'forgetfulness'.

    St. Thomas concludes: "From all this it is clear that even a very imperfect cognition of these most noble things confers the greatest perfection on the human soul. So even though things that are beyond reason are such that human reason cannot fully grasp them, still the soul acquires much perfection if it at least clings to them in some way by faith."

  • QUESTION 4 (chapter 6): Isn't it frivolous (estne levitatis?) and intellectually irresponsible for us to assent to the mysteries of the faith?
  • REPLY: It is right to worry about credulity as well as about pride and presumption. If the search for wisdom depends upon authority and there is no way to distinguish competing claims to authoritativeness, then it seems that the only alternative to skepticism will be a blind leap into any old dogma or creed. St. Thomas, however, warns us against credulity with the same sternness with which he warns us against presumption. In the case of the mysteries, he tells us, we can see how they are fitting (conveniens) and how they illumine our lives. But, in addition, we can show that it is reasonable to trust the authority that reveals them to us. That is, we can, at least retrospectively, discern many signs indicating that to accept the mysteries of faith on this authority is not credulous.

    • a. Miracles: St. Thomas mentions Christ's healings and raisings from the dead, but he is even more impressed by the spread of the early Church by idiotae and simplices filled with the Holy Spirit -- and this without the force of arms or a promise of sensual pleasure.

    • b. The witness of the martyrs: The early Church spread among persecutions.

    • c. The nature of the message: The Gospel does not play to our weaknesses: rather, things that surpass the human intellect are preached, the desires of the flesh are to be curbed (not so popular these days or at any time, for that matter) and the things of this world (wealth, glory, fame, power, etc.) are to be despised.

    • d. The fulfillment of prophecy: That all this happened was no accident, but was instead the fulfillment of the Scriptures.

    • e. The character of the founder: Note the contrast here with Mohammed, who according to St. Thomas was a violent man who spread his religion by the force of arms.

    • f. The marks of the church: One, Holy, Catholic, Apostolic

    • g. Respect for intellectual integrity

    The discussion of Mohammedanism is very interesting. While St. Thomas is not claiming that other religions and worldviews are devoid of truth, he nonetheless believes that it's foolish to trust those who throw reason to the winds, or who cater to people's weaknesses, or who have an unjustifiable faith in reason. Important here are the character of the founder, the nature of the message, etc. One intriguing criticism is that Mohammed's doctrine does not contain anything that could not be discovered by someone with modest intellectual endowment -- i.e., nothing akin to the mysteries of the faith. Notice that St. Thomas does not deny that there are truths taught by Islam, but claims that these truths are mixed with falsehoods. And one who is a true seeker of wisdom will not be satisfied with falsehoods.



G. Some theses concerning the relation between faith and reason (chaps. 7-8)

    1. Taking a deliverance of reason to respresent the best that reason can do and a deliverance of faith to be a proposition with theological certitude, it is impossible for a deliverance of reason to conflict with a deliverance of the faith.

    2. Apparent conflicts between the deliverances of reason and the deliverances of faith are possible, but they are always resolvable either by showing that a purported deliverance of reason does not have epistemic certitude of the appropriate degree or by showing that a purported deliverance of the faith does not have theological certitude of the appropriate degree or by showing that they are not really incompatible with one another.

    3. Philosophical arguments against deliverances of the faith can be met on their own grounds, i.e., they can at least in principle be shown, without any appeal to divine revelation, not to have epistemic certitude of the appropriate degree.

    4. Philosophical arguments against deliverances of the faith should be met on their own grounds because the integrity of reason is an important element of the faith.

    5. Reason in its postlapsarian state, while not corrupted to the extent that it yields falsehoods as certitudes, nevertheless needs the guidance of the faith to do its best at getting to the truth.

    6. Because of the likeness of effects to causes, human reason can invent arguments that render the faith plausible (a balance here between respect for mystery and respect for our natural desire to understand).