It is well known that in the thought of Thomas Aquinas what he calls the “preambles of faith” (praeambula fidei) occupy a prominent place. As he himself says, these are truths of faith that can be assented to by reason alone.¹ This distinguishes them from the articles of faith (the Incarnation and the Trinity, for example), the truth of which can only be assented to by faith. But why are they called “preambles”? The answer is that they are marked by a priority, at least a logical one, over the articles. Suffice it to say that among the preambles the existence of God stands out,² and the belief that God exists has an obvious logical priority over the acceptance of any article of faith.

In this article I will reflect on Aquinas's understanding of this particular preamble to faith, i.e. the existence of God. Did he understand it as the result of reason and evidence, or as the result of faith and divine grace? The question could also be put in these terms: what relationship does Aquinas see between the existence of God and the articles of faith? Some hold that there is a relationship of logical dependence between faith and the presupposition of God's existence. That is to say, in their view

However, given that (D) is clearly at odds with the Christian belief – explicitly mentioned by Aquinas³ – that faith is possible even for those who are unable to demonstrate God's existence, it could be argued that, according to Aquinas, at least for those who are precisely unable to do so, it is true that

Well, my intention is not only to show that both (D) and (F) are untenable, but also, and above all, that this is due to their dependence on an interpretation of faith as a purely intellectual assent (to divine revelation) which, in my view, does not belong to Aquinas's thinking. I want to show that a candidate solution, already proposed three decades ago, is consistent with an interpretation of the faith that is instead entirely ascribable to Aquinas. This is the interpretation of faith as not only the assent of the intellect but also the intervention of the will, which is not the same for everyone and which, for Aquinas, is ultimately due to divine grace.

In the first section, therefore, I will show that (D) and (F) are untenable because they depend on an intellectualistic interpretation of Aquinas's doctrine which, in my opinion, cannot be attributed to him. In the second section, I will recall the candidate solution mentioned above. In the third and final section, I will argue that, in contrast to (D) and (F), the solution recalled in the second section depends on an interpretation of faith as not reducible to intellectual assent to divine revelation, an interpretation which I consider to be fully attributable to the thought of Aquinas.

Let us first consider the positions that can be counted as (D). They are attributed to Aquinas by authoritative scholars, not necessarily his interpreters. I will limit myself here to one scholar of Aquinas, Anthony Kenny (1931-), and another major philosopher who is not a scholar of Aquinas, namely Alvin Plantinga (1932-). And before proceeding, let me note that these scholars’ support for (D) does not depend on their personal acceptance of (D). Plantinga rejects (D) in line with his well-known thesis that one can accept revelation without having to resort to any argument that is neither probable nor conclusive (see Plantinga, 1983). Kenny, on the other hand, supports (D), but distances himself from Aquinas by believing that no conclusive proof of God's existence can be offered (see Kenny, 1983, pp. 84ff.).⁴

So let us first consider Kenny's position on (D). In his view, providing evidence for God's existence is a necessary condition for any theistic belief. How can one firmly believe that God has revealed Himself without first justifying the belief that God exists? Kenny attributes this belief to Aquinas: “If belief in the existence of God cannot be rationally justified, there can be no good reason for adopting any of the traditional monotheistic religion” (Kenny, 1969, p. 4). In short, according to Kenny, Aquinas held that in order to adhere to Christianity it was necessary to support assent to the existence of God by demonstration. But this is clearly untenable. I have already pointed this out above, recalling what is said about it at the beginning of the Summa theologiae, even in the first article of the first question, which confirms its importance for Aquinas.⁵ I find particularly interesting Aquinas's reference to the ‘few’ who would have had access, not without effort and error, to the demonstration of God's existence:

In this sense, J. Wippel echoes him when he says that Aquinas “cannot mean that every Christian must first have demonstrated one or more of the preambles, such as the existence of God, before making an act of faith” (Wippel, 2012, p. 196).

Let us now turn to Plantinga's view that Aquinas found it necessary to provide arguments to support the assertion of God's existence. He admits that Aquinas was well aware of the fact that the vast majority of believers accept the existence of God by faith. Does this mean that Plantinga attributes (F) to Aquinas rather than (D)? No, because in Plantinga's view “believing by faith” would have seemed crazy and unreasonable to Aquinas if it were not based on evidence. Aquinas would have held that there was such evidence, and that it consisted in the set of arguments in favour of the fact that it is God Himself who has revealed Himself: “It is not foolish or irrational to take it that God has proposed for our belief just those items Christians suppose that he has” (A. Plantinga, 1983, p. 46). Accordingly, for Aquinas, believers would affirm the existence of God by faith, where faith is, however, supported by good arguments, without which it would be “foolish or irrational” to assent to revealed contents, including the existence of God.

Plantinga's interpretation may be convincing, at least at first sight. Certainly it is less in conflict with Aquinas's words than Kenny's. Indeed, Aquinas upholds the importance of arguments in support of any revealed content. He also calls such arguments the 'signs' of faith, as in the following passage in which he notes their usefulness:

For Aquinas, however, the assent of faith, in so far as it is supported by arguments, is primarily due to the impulse of the will moved by grace, as I will show later. That is to say, for him, while it is true that faith does not lack arguments in its support, it is nevertheless not because of them that one believes.⁶ By contrast, Plantinga's interpretation clearly ends up attributing to Aquinas the thesis that faith is simply due to the presence of arguments. This is the thesis, to which I will shortly refer, according to which faith is reduced to the mere assent of the intellect to revelation. But for Aquinas, as we shall see, faith goes far beyond mere intellectual understanding. Even in Plantinga's case, therefore, the attribution of (D) to Aquinas is not convincing.

Let us now consider (F), which, unlike (D), seems, at least at first sight, to be consistent with Aquinas's words. In fact, it is already clear from the passages quoted above that he openly states that most people hold the existence of God by faith. So, unlike (D), there is no need to appeal to interpreters who attribute (F) to Aquinas.

But even (F) is untenable, since it involves a petitio principii. According to (F), the existence of God is understood as both a presupposition and a consequence of faith in God. This has been usefully pointed out by J. Bishop, in whose view (F) implies that

Before Bishop, T. Penelhum had already identified this vicious circle, which “seems to be telling us both that one cannot believe in God unless one believes certain propositions about him, and that when one believes these propositions in faith, one accepts them as coming from him” (Penelhum, 1977, p. 141). A passage from the Summa theologiae that seems to support the existence of this circle is the following:

Aquinas seems to support (F) obviously with regard to those who are unable to prove the existence of God. But does this really lead him into the vicious circle that (F) suffers from? My answer will be in the negative. But in order to make my reasons clear, I must continue my investigation, first of all by referring in this section to the view of faith that both (D) and (F) imply in my opinion.

Both (D) and (F) seem to imply a purely intellectual view of faith, in which faith is reduced to intellectual assent to certain propositions, to certain contents of faith, because of the evidence found to support them. This implies that the existence of God must logically precede any other assertion about Him. Indeed, from a purely argumentative point of view, one cannot believe that God has done this or that unless one first accepts, by (D) or (F), that he exists.

In this sense, an article published in the 1950s by the French Jesuit G. de Broglie still deserves attention. He argues that when

Two well-known passages in the Summa theologiae confirm this interpretation. Focusing on the existence of God, Aquinas does not say that this is one of the preambles to the assent of faith, i.e., the act of believing (fides qua). Instead, he mentions the articles (praeambula ad articulos), i.e., the content of faith (fides quae) (Aquinas, 1920, I, q. 2 a. 2, ad 1.).⁷ Focusing on the object of faith, he reaffirms this belief by saying that the preambles in question “are prerequisites of the things which are of faith” (praeexiguntur ad ea quae sunt fidei) (Aquinas, 1920, II-II q. 1 a. 5, ad 3.).⁸ This has nothing to do with the act of believing in God. According to de Broglie, this act coincides with faith understood subjectively. For him, modernity has tended to confuse this subjective meaning with what we might call the “objective” meaning – that is, with faith understood as intellectual content and based on preambles. This would have led to the erroneous assumption that, for Aquinas, in order to believe in God (subjective meaning), the believer must first agree with the existence of God.⁹ We can infer from this that, given the circularity that plagues (F), one also ended up assuming that the act of believing in God requires prior justification, so that, at least for some, (D) would have seemed preferable to (F).¹⁰

In the third section of this article I intend to show that a possible solution to the problem of how Aquinas really linked the preambles to the articles of faith depends on an interpretation of faith not only as an intellectual act, but also and above all as an act based on divine grace. In the second section, however, I must first show what the possible solution is, a solution which J. Jenkins put forward some three decades ago.

According to Aquinas, there is a knowledge of the preamble to God's existence that we might say lies somewhere between (D) and (F). It is the knowledge that everyone seems to possess, albeit “generally” and “confusedly”. Aquinas speaks of this at the beginning of the Summa theologiae, in the second question, which is devoted precisely to the existence of God: “To know that God exists in a general and confused way is implanted in us by nature” (Aquinas, 1920, I, q. 2 a. 1, ad 1). It is a knowledge that does not coincide either with faith, which concerns only believers, or with the arguments of natural theology, which concerns only philosophers.¹¹ It is somewhat intermediate between (D) and (F), since, like faith, it is for everyone – even if, historically, revelation is only for some; like demonstration, it is a natural operation of the human intellect and does not depend on divine revelation.

Jenkins has attempted to offer the solution under consideration here in a way that implies precisely this kind of knowledge. He refers to a passage in Disputed Questions on Truth in which Aquinas confronts this position:

Aquinas replies as follows:

On the basis of this passage, Jenkins goes on to say that, for Aquinas, one can first hold that God exists, and then, by divine grace, be firmly convinced that what God has revealed, including His existence, is true:

Aquinas would therefore argue that before one comes to believe in God (to agree to the truth of the articles of faith), one can simply hold, on the basis of inconclusive evidence, that God exists and is pleased that one believes in Him.¹² If this argument is correct, then it can be said that

This avoids the vicious circle of (F), since believing in God is not believing by faith. Rather, it is “generally” and “confusedly” believing.¹³ It also avoids the contradiction inherent in (D) with Aquinas’ words.

One might object, however, that Aquinas's words also seem incompatible with (H), since Aquinas clearly states that the existence of God is accepted by demonstration, or at least (by most) by faith.¹⁴ In order to explain why I think there is no incompatibility, I must now focus on a very important aspect of the untenability of (D) and (F) and the plausibility of (H).

It should be noted that (H), while openly referring only to the condition of those who do not yet believe in God and only more or less hesitantly think that God exists, also refers – as J. Jenkins points out in the passage quoted above – to the condition of those who, having received grace, give their assent by faith to the revealed truth, including the existence of God. As I have already noted, Jenkins stresses that by grace one “comes to a firm conviction that God has revealed certain truths …, and, along with this, to the firm conviction that God exists”. Importantly, Jenkins does not simply say that the truths of faith must presuppose the existence of God. He says that by grace one comes to love God and believe what He has revealed (I will focus on this in the next section when discussing Aquinas's view of faith), and that this necessarily includes believing that He exists (which can also be confirmed by considering the fact that the Creed does not explicitly mention God's existence, taking it for granted once one believes what revelation says about Him). In this way, the vicious circle is avoided for those who believe, since grace does not lead to faith by logical presupposition: when God reveals Himself, He does so without having to emphasise that He exists; that He exists is implied. And, of course, the circle in question is obviously absent for those who do not yet believe, since those who do not yet believe accept that God exists not on the basis of faith, but on the basis of some evidence (and with more or less hesitation). This answers the objection that (H) is incompatible with Aquinas when he says that, among believers, most accept the existence of God by faith. It is not incompatible because, as Jenkins shows, while it is true that (H) openly refers to those who do not yet believe, it also refers to believers who accept the existence of God by faith.

So I have answered the objection, and now I have the opportunity to explain why this answer also shows that (F) is untenable. I said earlier that it is untenable because it falls into the vicious circle. But I can now add that it would not fall into the vicious circle if it considered only faith and not the logical presupposition. In the case of faith, as I have just shown, the logical presupposition between the existence of God and other revealed truths does not seem to make sense: one who believes in revelation can, by grace, give assent to many propositions about God that necessarily imply God's existence. The logical presupposition concerns the purely intellectual and argumentative aspect of propositions of faith. But (F) applies the logical presupposition to faith, to the act of believing, which de Broglie would call “subjective”; whereas the logical presupposition concerns the content of faith, and so applies appropriately to (D) as well as to those who, according to (H), are not yet believers and only hesitantly believe that God exists. In short, (F) affirms something true – what Aquinas claims, namely that most believers accept God's existence by faith – but inappropriately applies to it the logical presupposition. The logical presupposition does not concern the act of faith (fides qua) but the content of faith (fides quae), which regards the truth and the coherence of the propositions and which, according to de Broglie, is the non-subjective meaning of faith.

I can now add, as promised, why the answer to the objection considered above also reveals the untenability of (D). It is true that (D) is more consistent than (F) in that it applies the logic of presupposition to its own sphere, namely faith understood as assent to a set of noetic contents. Indeed, it is true to say that if one does not believe that God exists, one cannot logically argue that, for example, God assumed human nature for man's salvation. But the error of (D) is to reduce faith to a mere intellectual assent to divine revelation. For Aquinas, as I will show in the next section, faith is much more.

According to Aquinas, faith is “an act of the intellect assenting to the Divine Truth at the command of the will moved by the grace of God” (Aquinas, 1920, II-II, q. 2, a. 9). There are thus three dimensions of faith. The intellectual, because faith is an act of the intellect; the moral, because this act is due to the will to choose what is considered good, that is, to believe rather than to disbelieve; and finally the religious, because the will in question is due to the believer's relationship with God.¹⁵ As part of this relationship, God gives the believer charity, that is, love for Him and for one's neighbour. It is charity that “makes the will ready to believe” (Aquinas, 1920, II-II, q. 2, a. 10, ad 2.).¹⁶ In short, God makes believers love Him, trust Him, and believe what He has revealed. Moreover, Aquinas, following a long tradition,¹⁷ states that believers experience faith at different levels of intensity (see Aquinas, 1920, II-II, q. 5, a. 4). We can therefore conclude that the more one loves and trusts God, the more one is willing to believe his revelation. It is charity, then, that makes faith firm, and he who has charity believes in a paradigmatic way.¹⁸

Faith, then, is an intellectual act of assent that is ultimately caused by charity.¹⁹ Faith and love are directly proportional. Those who are steadfast in their faith are also steadfast in their love of God, where God is understood as the greatest good. The more believers believe, the more they are expected to love the greatest good.

Before showing how this interpretation of faith supports (H), I need to refer to the purely intellectualistic interpretation, so that I can also show, more than I did in the second section, how both (D) and (F) depend on it.

I call this interpretation ‘intellectualistic’ because it insists only on the intellectual aspect of faith – faith understood as the act of the intellect giving assent to revelation – from which it follows that faith can, at least in principle, be rejected if assent is denied by the available evidence. This interpretation does not take into account either the role of the will or that of charity, which depends on grace and which, for Aquinas, is what makes faith firm.²⁰

I have already referred to this type of interpretation when I noted that Jenkins deals with it not because he thinks it is worthy of attention, but simply because of how widespread it has become in the course of modernity. For the sake of brevity, I will limit myself here to mentioning two authoritative scholars. The first is not an interpreter of Aquinas. He is R. Swinburne, according to whom faith for Aquinas is a mere 'propositional belief', a mere intellectual assent by the force of evidence, to the point that faith would not be meritorious, as Aquinas consistently maintains (see Swinburne, 2005, pp. 138ff.).²¹ The second authoritative scholar is A. Kenny, who is also a major interpreter of Aquinas and whom I mentioned above in connection with (D). I refer to him now because his interpretation of Aquinas's doctrine is easy to understand and therefore easy to summarise.

Kenny argues that faith is a vice and not, as Aquinas and many others believe, a virtue, because the firmness that should accompany it is not supported by sufficient evidence. For this reason, he says, the high degree of devotion proper to faith is “really objectionable” (Kenny, 2007, p. 396). Kenny presents Aquinas's doctrine of faith in these terms: faith is “the acceptance of the testimony of a sacred text or of a religious community” (ibid., p. 394). This acceptance is characterised by certainty and irrevocability. Believers believe irrevocably (at least this is what is expected of them), even though there is no conclusive proof of this irrevocability. Similarly, they are unwilling to change their minds and abandon their religious beliefs when presented with arguments to the contrary. For this reason, Kenny believes that “faith is not, as theologians have claimed, a virtue, but a vice” (Kenny, 1992, p. 57).²² Faith can only be a virtue if it is supported by conclusive evidence, and if believers are prepared to abandon it if compelling evidence against it emerges. According to Kenny, two things have to be done. First, as I also showed in the first section concerning (D), the existence of God must be proved, because it cannot simply be believed by faith, faith being a vice. Second, the historical facts that are part of divine revelation must be proven to be true: “Whatever are the historical events which are pointed to as constituting the divine revelation must be independently established as historically certain” (Kenny, 1992, p. 57). But neither the existence of God nor the historical facts of the biblical narrative can be proved to be true (see Kenny, 1969, p. 4; Kenny, 1983, p. 55), which is why, as I have already noted, for Kenny faith is a vice. The certainty and irrevocability it requires should be supported by conclusive evidence, but there is no such evidence.

However, Kenny simply fails to take into account that Aquinas, as I have pointed out above, is aware that the certainty and irrevocability in question here is due to the will to believe and not to conclusive evidence. According to Aquinas, the will in question is specifically moved by God's grace to cause the intellect to assent to divine revelation.

I can now return to the reasons why I think that this interpretation of faith, which I have called ‘intellectualistic’, brings out (D) and (F), as well as the reasons why, on the contrary, I think that the interpretation of faith of the believer that is not limited to the intellectual dimension, brings out (H).

Both (D) and (F) are due to the necessity that the existence of God, as the preamble of faith, logically precedes all other contents of Christian revelation. I have already explained above that the reason for this is that, in this case, revelation is not understood as a relationship that God establishes with potential believers but is instead seen solely as a set of noetic contents (and faith is therefore seen as assent to such contents, if sufficient evidence is given for it). Of course, there must be relations of logical presupposition between these contents, which are connected by argumentation, as I mentioned earlier. Hence (D) and (F).

The problems that arise with (D) and (F) are due to the fact that, as de Broglie explained, faith cannot be reduced to the intellectual dimension alone. If one considers that it is also an act of divine grace, then (D) is unacceptable because most people can be recipients of this grace even without being able to prove anything; (F) is unacceptable because, as I have already shown in the second section, although it acknowledges that it is by faith that most people are convinced that God exists, (F) applies to it the logical model of presupposition, which does not apply to grace and the act of faith, but is instead typical of the intellectualistic interpretation of faith.

If, on the other hand, we adopt the interpretation that is not merely intellectualistic, on which I have focused so far, (H) emerges and is proposed as a suitable explanation of how the preamble in question relates to the articles of faith.

On the one hand, (H) allows the logical model of presupposition to be maintained. In fact, (H) shows that before coming into contact with divine revelation, that is, before faith has intervened, it is necessary to be in possession of the preambles, however hesitantly argued, since they allow one to form an idea of the revealed truths. Indeed, one could not accept God's revelation if one did not have an idea, however hesitantly held, of what God might be (the "generic" and "confused" idea I mentioned several times above).

On the other hand, (H), as suggested by Jenkins, is compatible with the fact that the firmness with which one argues for the existence of God, a firmness required of the believer (at least the paradigmatic believer), is possible by faith - though this does not prevent educated people, at least in principle, from holding to it with reason.

It can therefore be argued that, unlike (D), (H) confirms Aquinas's view that truths of faith which are also preambles to faith can be held firmly by all believers, not just those who can prove the existence of God. Unlike (F), (H) does not fall into circular reasoning. To emphasise the similarities, we can say that (H), like (D), accepts the logical model of presupposition. The existence of God can certainly be understood as a necessary presupposition with respect to other contents of faith, although it is a presupposition that can be accepted even with hesitation. Like (F), (H) confirms that all truths of faith, including the existence of God, can be held firmly by faith.

In this article I have argued that the difficulties into which both (D) and (F) fall are due to the assumption of the logical model of presupposition, which is proper to the intellectual dimension of faith. By no means did I intend to argue that this model and dimension should be denied. On the contrary, they should be maintained, but integrated into a more comprehensive interpretation of faith, which is not only about the intellect, but about the human person in its entirety, that is, where the will to believe and the relationship of love (charity) with God also play a role. Once we have considered this more comprehensive view of faith, which I believe is fully attributable to Aquinas, (H) emerges, while (D) and (F) show their untenability. (D) is untenable because it holds that in order to adhere to the articles of faith, one must agree to the existence of God by means of demonstration. (F) is untenable because, although it correctly states that assent to God's existence can be given by faith, it accepts the argumentative and logical model of presupposition and thus falls into circularity. Contrary to (D) and (F), (H) is more comprehensive, like the view of faith from which it emerges, which is not limited to the intellectual dimension alone. On the one hand, (H) recognises the intellectual dimension of faith by accepting its logical model of presuppositions; on the other hand, it implies and opens up the consideration of faith as something that goes beyond intellectual assent and ultimately derives from God and his grace. In this sense, (H) asserts that one can accept the preambles through faith and with the firmness expected of a believer, without falling into circularity.²³