Reason, your viceroy in me, me should defend, But is captiv'd, and proves weak or untrue.

John Donne

The holy that is obvious, the sacral, is never the true holy. The true holy is spirit, not thing. The Deus dixit is revelation, not revealedness.

Karl Barth

Accordingly, the disposition whereby the created intellect is raised to the intellectual vision of the divine substance is rightly called the light of glory.

Thomas Aquinas

Introduction: Reformed Theology and the Early Enlightenment

How did Christian theology reach the point at which John Toland could claim that “there's no Doctrine of the Gospel contrary to Reason…neither is there any of them above Reason; and by consequence…none is a mystery” ([1696] 1997, 19)? Several scholars have suggested that the epistemological trajectories of Reformed theology in the sixteenth and seventeenth centuries are largely responsible for the new conceptions of Scriptural reason and the displacement of theological mysteries in the early Enlightenment. For instance, Michael Legaspi has suggested that the crucial shift came with the hermeneutical practices within the Protestant Reformation: the exalted status of the Christian Scriptures was undermined in the sixteenth century by Reformers’ insistence on the literal sense of the text (2010, 3–26). Legaspi suggests that Scripture had functioned as a shared, unifying cultural text in Roman Catholic Europe before the Reformation. The Protestant emphasis on the literal sense called forth the application of a destructive probabilistic reasoning about its origins and meanings, making a shared Scripture impossible. This transition was already well under way by the beginning of the seventeenth century. ¹

Focusing more on the subsequent century, Frederick Beiser's The Sovereignty of Reason suggests a similar narrative—but with a concentration on British theology and philosophy (1996). ² The Protestant Reformation unleashed reason in its totalizing forms, paradoxically undermining adherence to Scripture as locus of theological authority. Beiser traces a genealogy from Calvin and Luther through to Richard Hooker and to the Cambridge Platonists. On Beiser's reading, Reformed theology was essentially fideistic, taking its starting point as it did from the notion of the Deus absconditus or hidden God. The Reformed picture, suggests Beiser, was a fundamentally different one from that of Aquinas, who held that human beings can know God's own essence and its expression in natural law. Beiser claims that the Reformed made God absolutely inscrutable, whereas “In the Thomistic tradition, reason does know, even if very dimly, the divine essence itself, insofar as the law of nature participates in the eternal law” (1996, 44). ³ The problem of the Deus absconditus, suggests Beiser, led to unique lacunae in Reformed theology—most notably the question of certainty about God's nature and our status with him. ⁴ Beiser claims that seventeenth‐century Reformed theology therefore unwittingly gave birth to a “rational soteriology” (1996, 163). That is, while the Magisterial Reformers and seventeenth‐century Puritans were fideists, Richard Hooker and the Cambridge Platonists were rationalists. The Reformed forced a choice between these two extremes, with rationalism eventually winning the day. Paradoxically, it was because of the Reformed that Scripture became subservient to reason. This led to the increasing naturalization both of Scriptural reason and of supernatural truth in the early Enlightenment.

It certainly seems correct to say that the seventeenth century is a period in which a very important shift begins in attitudes toward Scripture and reason. Overall, Beiser and Legaspi are correct to suggest that Scripture is undermined as a shared cultural and theological source by the beginning of the eighteenth century. But do their narratives about the mechanisms of this change fit the evidence? In this article, I will argue both that Reformed theology is closer to important aspects of Thomistic thought than Beiser allows and that Reformed thought in the period does not collapse into either fideism or rationalism. ⁵ I introduce the tradition of “eschatological concordism” and suggest it draws on central elements in both Aquinas and Calvin. These elements are the lux gloriae tradition (Aquinas) and the autopistia doctrine (Calvin). I then argue that the historical groundwork for rationalism was laid in the period by the Socinians, who insisted on an immanent concordism between scriptural revelation and natural reason. I outline the views of three Reformed authors (Nathaniel Culverwell, Francis Turretin, and John Owen) in diverse institutional settings (Cambridge, Geneva, Oxford) to show that the Reformed tradition distances itself from both such a rationalistic trajectory and its fideistic antithesis—reaffirming instead eschatological concordism. Finally, I suggest that a kind of rationalism is adopted by some influential Anglican and Nonconformist figures in the middle and late seventeenth century (More and Locke). These figures’ adoption of immanent concordism from Socinian or Platonic influences is a more likely source for the naturalization of Scriptural reason than Reformed thought.

The Sources of Eschatological Concordism before the Seventeenth Century

I wish to outline and trace a tradition (reasserted in the seventeenth century) that includes two core elements: (1) the autopistia doctrine and (2) the lux gloriae doctrine. ⁶ These elements originate from Calvin and Aquinas, respectively; but the seventeenth‐century Reformed draw from each to provide a framework for the defense of Scriptural mysteries. As we shall see, these traditions not only connect the Reformed to their Medieval counterparts but also constitute noetic bulwarks against the immanentization of Scriptural mysteries.

In both the Summa Contra Gentiles and the Summa Theologiae, Thomas Aquinas deftly moves the reader to consider the transcendent horizons of our intellectual nature (SCG III.47–56 and ST I, q. 12). He argues that the essence of God cannot be discerned (even by the most exacting exercise of reason) in one's earthly life: “God cannot be seen in His essence by a mere human being, except he be separated from this mortal life” (ST 1.12.11; see also SCG III.47). ⁷ This is because the mode of human cognition in this life is tied to our bodily nature and is circumscribed by our finite understandings. Human creatures admittedly apprehend the natures of things, which dimly participate in their Creator's being. And our reason is directed toward God, insofar as reason's earthly exercise seeks a good that continuously eludes our grasp. However, even as we hear of the Divine Being through revelation, his positive essence and being remain shrouded in mystery until we depart this life. This is in substantial part because the true knowledge of God's own being belongs by nature to God alone (SCG III.51). After all, a finite being, such as a human creature, cannot comprehend (at least through the exercise of her own finite nature) the infinite essence of the Deity (SCG III.49).

And yet, Aquinas holds that we are destined to see God's essence at the end of life. Aquinas writes: “It is according to this vision [of God] that we become most like unto God, and participators of his bliss, since God understands his substance by his essence, and this is his bliss” (SCG III.51). Accordingly, Aquinas holds that there must be some final act of illumination by which God himself grants to the creature the capacity to see the divine essence. Drawing on the language of Scripture, ⁸ Aquinas calls this supernatural capacity the light of glory: “the disposition whereby the created intellect is raised to the intellectual vision of the divine substance is rightly called the light of glory [lux gloriae]” (SCG III.53).

We must note here the role Aquinas acknowledges for the lux gloriae in relation to human nature. It is the self‐transcending perfection of that nature—in both its conative and cognitive aspects. Put otherwise, this light of glory constitutes the final goal and integration point of both reason's exercise (in seeking some final good) and of the assent of faith (in acknowledging divine self‐revelation). In the Summa Contra Gentiles, for instance, the discussion of the lux gloriae follows an exhaustive discussion of alternative candidates for the final good or object of happiness for human creatures (SCG III.1‐44). The summum bonum is not wealth or worldly power or even the exercise of virtue. For, if death is the total end of these goods, then all my desires and deliberation will finally come to nothing. The exercise of deliberative reason therefore points beyond these creaturely realities—and does not grasp in this life the true essence of the final good. Aquinas asserts that only in the light of glory is that Good positively enjoyed.

Similarly, when Aquinas discusses the mysteries of faith in the Summa Theologiae, he rejects the notion that we can know mysteries such as the Trinity in any complete sense through rational reflection. Indeed, the “dignity” of faith consists in “its being concerned with invisible things, that exceed human reason” (ST 1.32.1). Crucially, Aquinas relates his discussion of the limits of our understanding of mysteries like the Trinity back to the framework of the lux gloriae (ST 1.32.a1). Thus, with regard to the supra‐rational mysteries of faith, Aquinas suggests that the light of glory will provide the only positive means of resolution between such mysteries and reason—because only at the lux gloriae will divine reason show itself to human creatures. ⁹ The light of reason and the truths revealed in Scripture are fully consonant, but one cannot discern their harmony until after death.

The second element of eschatological concordism is the autopistia [self‐authenticating] doctrine, advocated most significantly by John Calvin. (There are, however, places where Aquinas also suggests a version of the doctrine [SCG I.1.8; ST 1, q.32, a.1, respondeo; ST II‐II, q.2, a.9, reply ob. 3; and ST II‐II, q.6, a.1, respondeo].) Because of the frailty and fallenness of human cognition, reason is neither the ground of true faith nor the first principle of theology. Rather, the Holy Spirit testifies to the authenticity of Scripture as revelation. As Calvin writes:

unbelieving men … wish and demand rational proof that Moses and the prophets spoke divinely. But I reply: the testimony of the Spirit is more excellent than all reason. … For as God alone is a fit witness of himself in his Word, so also the Word will not find acceptance in men's hearts before it is sealed by the inward testimony of the Spirit. ([1559] 2006, Vol. I, 78) ¹⁰

However, Calvin does allow that reason—along with the historic testimony of the church—has a supporting role to play in matters of faith. First, rational argument is involved in individuals coming to consider the Christian revelation. ¹¹ These arguments include the antiquity of Scripture, the miracles worked by Jesus and Scriptural prophets, and the testimony of the historic church to the Scriptures. But these arguments are not the ground, properly, of full assent to Scripture. They are rather signs of its veracity that impel one to consider its truth and provide some rational support for its claims. The certainty of genuine faith (certitudine divina) always remains a work of the Spirit: Scriptural truth, conceived of as a self‐testimony from God, is supra‐rational. Indeed, Calvin suggests that the ultimate object of divine revelation is God himself, whose positive being transcends our understanding. Calvin writes:

[Scripture] is sealed upon our hearts through the Spirit. Therefore, illuminated by his power, we believe neither by our own nor by anyone else's judgment that Scripture is from God; but above human judgment we affirm with utter certainty (just as if we were gazing upon the majesty of God himself) that it has flowed to us from the very mouth of God by the ministry of men. ([1559] 2006, Vol. I, sec. vii.5; quoted in Muller 2006, Vol. 2, 257)

This emphasis on Scripture as self‐authenticating [autopistia] is part of the core of Reformed theology, and it prevents probabilistic reason from taking upon itself the role of final arbiter of divine mysteries. From the perspective of such a theology, the demise of this insistence opens the door to the presumption that Scriptural mysteries are noetically guilty until proven innocent. But the seventeenth century was a time in which the autopistia doctrine began to be seriously challenged. The first main challenges to the noetic bulwark of eschatological concordism were presented by the Socinians. It is to that movement that we now turn.

The Naturalization of Scriptural Reason: The Socinian Innovation

I will suggest two main components to the naturalization of Scriptural reason in the seventeenth century: the rejection of the lux gloriae framework (in favor of immanent concordism concerning divine and human reason) and the rejection of the autopistia doctrine in some radical Reformed circles (in favor of several forms of rationalism about assent to revelation). These two departures from the Reformed tradition are expressed strongly in Socinian writers, and they gradually find their way into more mainstream theologians of the period. In short, when the transcendent frame of reason's exercise is maintained, so are divine mysteries. When our noetic horizons are drawn down within nature, by contrast, divine mysteries cannot be sustained. For, as we shall see, making noetic horizons immanent increasingly forces mundane reason to adjudicate supposedly revealed mysteries on its own terms. To fail to provide rational descriptions of the positive possibility of such mysteries implies that they are irrational; immanent concordism is therefore held in an unstable relation to any genuinely transcendent mysteries.

In the late sixteenth and early seventeenth centuries, some radically inclined Protestants began to advocate an inflated role for reason in religious matters. These members of the Radical Reformation were often called Socinians because they drew much of their basic outlook from the Italian theologian Faustus Socinus (1539–1604). ¹² The Socinian position married theological rationalism to a narrow form of Biblicism. Their rationalism was expressed in the intimation that reason (as opposed to Scripture's self‐authentication [autopistia]) is the proper principle of assent to Scriptural truths as revealed. The authors of the Socinian Racovian Catechism argue:

It (i.e., reason) is, indeed, of great service, since without it we could neither perceive with certainty the authority of the sacred writings, understand their contents, discriminate one thing from another, nor apply them to any practical purpose. (Rees 1818, 15)

The notion that reason has a proper subordinate role in articulating the meaning of Scripture—or dispelling positive objections to it—is certainly not an affront to traditional Reformed (or Thomistic) thought. Quite the contrary. ¹³ The innovation here is that the Socinians seem to be suggesting that reason is the proper source of certainty in the authority of the Scriptures—something that the Reformed consistently denied. The Socinians’ seemingly sole focus upon probabilistic arguments for the conviction of faith is evident in the first section of the Racovian Catechism, where the reliability of the Scriptures is argued for strictly on the basis of historical and probabilistic arguments (Rees 1818, 2–13). The autopistia doctrine—and the theological notions of inspiration or divine testimony—are notably absent.

The Socinians also tended to re‐interpret traditional revealed mysteries—by suggesting that all supposed conflicts between human reason and divine revelation must be positively resolved. The Socinians rejected received doctrines (such as the traditional understanding of the atonement and the resurrection of the body) on the basis that such doctrines are supposedly “repugnant to both Scripture and reason” (Rees 1818, 126. Thomas Edwards lists one of the innovative religious errors of the 1640s as the claim, “That right Reason is the rule of Faith, and that we are to believe the Scriptures, and the Doctrine of the Trinity, Incarnation, Resurrection, so far as we see them agreeable to reason, and no farther” (1697, 19). This was clearly a polemically charged synopsis of the Socinian attitude toward reason and revelation; the accuracy of the report therefore can be questioned. But there was evidently an increasing awareness in the mid‐seventeenth century that reason was taking on a magnified role as both the grounds of assent and as the final bar at which (putative) revelation must prove its positive possibility. ¹⁴

Socinians themselves came to expressly affirm that the above is the only kind of supra‐rational truth in the Christian religion: divine mysteries are merely propositions that are revealed in Scripture and would not have been discovered by independent human reason. Once revealed, however, even propositions above reason can be seen to be totally in accord with human reason. So, Socinian theologians reject any notion that the mode of supra‐rational propositions’ coherence is beyond our rational capacities. The Socinian John Krell (1590–1633) suggests such a view when he writes, “mysteries [of religion] are above human reason but … It is in fact reason, which alone perceives, embraces, and defends the mysteries revealed to it, which by itself it could not discover” (Williams 1980, 676. Reason can see the reasons within all divine mysteries—even within earthly life. The transcendent frame for the harmonization of reason and Scriptural mysteries is replaced by a fully immanent concordism.

The Socinian theologian Andreas Wissowatius insisted even more provocatively on the centrality of the individual's reasoning about a putative revealed mystery: “the truth in these [theological] controversies, and what above all is the true proposition of Holy Scripture, is discerned by every man through sound reason who is endowed with it” (Williams 1980, 676). Wissowatius also suggests that the supposedly revealed proposition must form in the believer a positive conception whose signification can be understood:

If to have to believe something, [and] it is not necessary that anything be understood, then anything could be rightly proclaimed to any man in whatever foreign tongue, of which he would hear only the sound, but at the same time he would not understand what the words signify, and he be asked whether he believes those things said, and whether to these as to things true, he professes assent and approbation. But is this not, I ask, absurd …? (Williams 1980, 678)

Such a description is clearly intended to apply to traditional formulations of doctrines like the Trinity, Incarnation, and resurrection of the body. Rather than assenting to a revelation about the divine nature as supra‐rational, the Socinians suggest that reason must be able to speak authoritatively about the positive intelligibility of all putative revelations. This outlook, I would suggest, holds together with the claim that reason is the ultimate grounds of assent to Scriptural revelation. If reason is the final grounds of assent to a proposition as revealed, it follows that reason should also act as judge of the possibility of a putatively revealed claim. For if reason cannot show how a supposedly revealed proposition is at least coherent, then it is surely to be judged less probable that it is actually revealed. Since there are not divine mysteries that transcend human conception, there is no appeal to the framework of the lux gloriae in the Socinian figures. (Or, one might suppose, since there is no framework of the light of glory, genuine Scriptural mysteries cannot retain their transcendence.) Human reason and divine reason are essentially one (although human reason is finite and discursive in a way that divine reason perhaps is not). As will become evident below, this connection is recapitulated in more mainstream rationalist figures of the later seventeenth century.

The Reformed Response to Socinianism

According to the narrative about the emergence of Enlightenment views of Scripture and reason outlined in the introduction, Reformed theology left reason totally unrelated to divinely revealed truth. This lacuna was the crucial one that led to the “rational soteriology” of the seventeenth century. However, if the Reformed advocate frameworks for relating reason and divine revelation, then rationalism is not an obvious outworking of the shortcomings of the Reformed stance to Scriptural reason. Crucially, the evidence for such noetic bulwarks in the Reformed tradition—as well as their recapitulation of Thomistic themes—is significant.

The intellectual milieu of the University of Cambridge in the seventeenth century provides several examples of such bulwarks against rationalism and fideism. One of the most significant was the outlook of the Reformed author Nathaniel Culverwell (1620–1651), who delivered a series of lectures in the Chapel of Emmanuel College in 1645–1646. ¹⁵ The lectures would be published posthumously in 1652 as An Elegant and Learned Discourse of the Light of Nature. Culverwell was clearly concerned about the trajectory of religious opinion in England during his day. For, on the one hand, there were those (the fideistic party) who gave little or no place for reason's exercise with regard to moral or religious assent ([1652] 2001, 10–17). On the other hand, Socinian dogmatic innovations had made an impression upon the consciousness of Culverwell and his orthodox contemporaries. The Socinians were challenging the core of traditional Christian doctrine (including not only the Trinity but also the Incarnation, atonement, and resurrection of the body) on the basis of putative arguments from reason. Culverwell complains in the Discourse that, despite reason's divine origins, “Socinus has burnt his wings at this Candle of the Lord” (Culverwell [1652] 2001, 15).

Culverwell therefore sought to emphasize the moderate role of reason with regard to moral and theological matters. In the first half of the Discourse, Culverwell explores the proper exercise of reason concerning the moral law. In the second half of the work, he exposits the traditional notion that reason has both its source and end in the divine reason. Reason is both “Derivative Light” and “Ascendant Light” that participates in divine reason. Because the exercise of reason (especially in moral matters) points beyond itself to a transcendent end, it has a proper place in directing humankind “in the ways of God” (Culverwell [1652] 2001, 18). And because the light of reason is a “weak participation” in divine reason (Culverwell [1652] 2001, 88), it follows “That there's nothing in the mysteries of the Gospel contrary to the light of Reason; nothing repugnant to this light that shines from the Candle of the Lord” (Culverwell [1652] 2001, 16).

Importantly, however, Culverwell never adopts the Socinian suggestion that reason is the principle of assent to revealed theology or the final arbiter of revealed mysteries. In fact, Culverwell insists that the “voice of God” must speak to the creature as its own ground of assent (Culverwell [1652] 2001, 164). Accordingly, “This holy Spirit of God creates in the soul a grace answerable to these transcendent objects” (Culverwell [1652] 2001, 164). If God's self‐testimony could not be authoritative, that is, “if he should reveal his mind by a creature, there will still be some tremblings and waverings in the soul” (Culverwell [1652] 2001, 164). God must bring about the certainty of faith inwardly in the individual. Valuing reason even as he does, Culverwell reiterates the autopistia doctrine.

On the other hand, Culverwell insists that, because God is the source of both human reason and the mysteries of faith, reason can answer objections to the rational coherence of those mysteries:

[Divine mysteries] were never against Reason, they were always above Reason. ‘Twill be employment enough, and ‘twill be a noble employment too, for Reason to redeem and vindicate them from those thorns and difficulties, with which some subtle ones have vext them and encompass them. (Culverwell [1652] 2001, 164)

Culverwell's position is that the positive possibility or comprehensibility of the revealed mysteries transcends reason; but reason can properly be employed to refute supposed demonstrations of those mysteries’ impossibility. As an example, Culverwell suggests the resurrection of the body is just such a revealed mystery that can be vindicated—even though some have impugned it on the basis of Platonic philosophy. Plato “looked upon the body as the blot of nature”; such an attitude had led to the demotion of the resurrection doctrine among some of Culverwell's Cambridge contemporaries (Culverwell [1652] 2001, 89). But Plato's low view of the body does not flow from reason itself but from his ignorance of the body's possible glory. The body's “ancient glory” is obscured by Plato because of “his ignorance of the resurrection, for had he but known what a glory the body was capable of, he would have entertained more honorable thoughts of it” (Culverwell [1652] 2001, 89). Neither Plato nor the Platonists have demonstrated their low conception of the body from reason—nor that the resurrection of the body is impossible.

Finally, Culverwell holds together his allowance of a role for reason with his acknowledgement of supra‐rational mysteries by insisting that clear perception of the harmony between reason and revelation is possible but deferred until the supernatural gift of the lux gloriae after death. In a stirring chapter at the end of the Discourse, Culverwell draws heavily on Aquinas's Summa Contra Gentiles to articulate the doctrine. The light of glory is not the gradual intellectual ascent of Neoplatonism; it is rather the “adding of a new supernatural disposition” that transforms the soul into a fit receptacle to apprehend the divine essence. The human soul is thereby made to be satisfied “with that summum bonum it has so much long'd for” ([1652] 2001, 196). ¹⁶ That is, the final good is gained only after death. Faith and reason finally “kiss each other” (Culverwell [1652] 2001, 10). The Divine Being was apprehended vaguely in the perception of the natural law; he was assented to (in his positive, Trinitarian essence) by faith in divine revelation. But after death this Being is seen to be the object upon which reason and faith converge. This insight into the divine essence even discloses the rationality of those mysteries of the Christian faith that had been assented to by faith but had remained firmly above reason. Thus, the summum bonum that reason seeks is disclosed in its fullness only by a final act of divine self‐disclosure.

Culverwell finishes his Discourse by returning to his theme of the Proverbs 20:27:

This Candle of the Lord may shine here below, it may and doth aspire, and long for happiness; but yet it will not come near it, till he that lighted it up, be pleased to lift it up to himself, and there transform it into a Stare, that may drink in everlasting light and influence from its original and fountain‐light. (Culverwell [1652] 2001, 198)

Far from anticipating the Enlightenment displacement of Scripture by natural reason—or making reason and revealed mysteries irreconcilable—Culverwell carefully reinforces (against the burgeoning Socinianism of his day) the framework of eschatological concordism.

In the Reformed scholasticism of the Genevan theologian Francis Turretin (1623–1687), one sees the same framework for the relation between reason and scriptural mysteries. Like Calvin and Culverwell, Turretin insists that reason is not the first principle of assent to theological truths ([1696] 1992, Vol. I, 11; 17). Indeed, reason is not even given the role of primary principle of assent to the proposition that Scripture is revelation: “The mysteries of faith are beyond the sphere of reason … Reason is the instrument which the believer uses, but it is not the foundation and principle upon which faith rests” (Turretin [1696] 1992, Vol. I, 24–25). Accordingly, since the ground of assent is the testimony of God himself, one need not reinterpret or reject revealed mysteries in the way the Socinians are wont to do. For the Socinians reject Scripturally attested doctrines on the basis that they cannot explain the mode of their possibility. But Turretin responds that, “it would be impious for a finite mind to circumscribe within narrow limits the infinite power of God” (Turretin [1696] 1992, Vol. I, 28). ¹⁷

However, if one acknowledges that there are some propositions above reason, can one hold that there is a proper use for reason in religious matters at all? Turretin seeks to outline two primary roles. First, probabilistic arguments can be made about the authenticity of divine revelation (on the basis of miracles, etc.). Turretin even goes as far as claiming that the light of nature has a use as “a subjective condition in man for the admission of the light of grace because God does not appeal to brutes and stocks, but to rational creatures” ([1696] 1992, Vol. I, 10). Turretin's position seems to be that arguments from reason provide the subjective grounds for apprehending the Scriptures as revealed—though such arguments are not the objective grounds. The human creature is not commanded to disavow all reasoning about religious truths. But because these arguments are merely probable, they are not the proper source of the certainty of faith. Such certainty stands always apart as a separate source of conviction—working with, but never reducible to, the exercise of reason. Probabilistic arguments therefore are not to be weighed against the self‐testimony of God in Scripture.

Furthermore, reason can be employed as an instrument in eliminating religious error and false interpretations of Scripture. However, Turretin claims that this exercise of reason ought not to stand outside and prior to the divine self‐revelation as a supposedly independent source of its positive authority: reasoning about divine mysteries is rather used instrumentally from within the circle of assent to divine self‐testimony ([1696] 1992, Vol. I, 33). Turretin employs the example of the Reformed argument against the Lutheran doctrine of the ubiquitous presence of Christ's body. The Reformed argument is a “mixed syllogism,” that is, an argument one or more of whose premises is based on reason and one or more of whose premises is based on revelation. In these arguments, reason is not the foundation of the conclusion; rather, faith in revelation is the ground. Reason is “only the means and instrument by whose aid the truth virtually concealed in the other premise is elicited” ([1696] 1992, Vol. I, 26). However, reason does establish the connection between the premise accepted on the basis of reason and the premise established by revelation. ¹⁸ That is, such mixed syllogisms do not make reason the ground of theological assent; they rather educe the implications of revealed propositions. So reason has a role in articulating arguments against certain theological claims—even while revealed propositions’ authority stands quite independent of reason. Turretin's example is illuminating:

I deny that the glorified body of Christ is everywhere, having taken from Scripture this mean, that it is a real body. But the major (that nobody is everywhere) is drawn from reason. Hence in such arguments the theological conclusion follows from the mean inferring, and the logical from reason which connects the consequence. (Vol. I, 27)

The “mean” here is the second proposition in a syllogistic argument, whereas the “major” is the first proposition. The “logical” conclusion depends only upon reason, whereas the “theological conclusion” depends upon assent to the revealed proposition in the mean. So, In order for ubiquity to be above reason, its advocates would have to either deny the “mean” or undermine the logical force of the conclusion. Reason therefore has a role in eliminating the error of the ubiquitous body of Christ—without collapsing into the Socinian claim that there is no area of revealed truth above reason.

Finally, Turretin gives the lux gloriae a similar role as do Aquinas and Culverwell. In Volume III of the Elenctic Theology, Turretin claims that the gift of the lux gloriae marks the transition from faith (as full assent on the basis of testimony) to sight or intellectual knowledge (as full assent as immediate and intuitive intellectual perception):

God can be seen of man by a spiritual and internal vision alone. In this life, indeed, by the light of grace and by the specular knowledge of faith; in the other life, however, by an intuitive and far more perfect beatific vision and by the light of glory. ([1696] 1992, Vol. III, 611)

Admittedly, Turretin departs slightly from the Thomistic tradition of the lux gloriae—in that he is demure about whether the soul in the light of glory “will immediately see the very essence of God or only some reflection of it” ([1696] 1992, Vol. III, 611). This modesty is characteristic of the Reformed and is inspired by the facts that (1) Scripture does not explicitly state that the light of glory consists in seeing God's own essence as God sees it, and (2) there remains an infinite distance between created and divine intellect. ¹⁹

But, just like Aquinas, Turretin claims we will see God by “an intuitive vision” and by “a faculty … elevated above its own natural grade by supernatural grace” ([1696], 1992, Vol. III, 610–611). The light of glory not only allows a perfected apprehension of those truths formerly assented to by faith alone (mysterium fidei), it also allows us to see that final good (summum bonum) that was intimated by—but which eluded—the light of nature in this life. ²⁰ Faith and reason meet and are transcended in the lux gloriae. This framework provides Turretin a check against Socinian dismissals of supra‐rational mysteries—while insisting that the light of nature is a divinely sanctioned gift.

Our final Reformed author was John Locke's Dean at Christchurch Oxford. John Owen (1616–1683) insisted on both the autopistia and lux gloriae traditions. Furthermore, like Culverwell and Turretin, Owen was deeply concerned with the emergence of Socinian rationalism—having penned the 1655 Vindiciae Evangelicae as a response to Socinian John Biddle.

Owen insists in the source of the authority of Scripture is its “Divine Originall” or divine source. That is, Scripture does not derive its proper authority from external grounds but from its speaking as the Vox Dei (1659, 28–29). Owen allows for the legitimacy of arguments for the divine inspiration of the Scriptures, but he suggests that the Spirit's self‐testimony is the unique “formall Reason” of assent (1659, 32–33; see also Helm 1999, 167).

The Oxford theologian notes that some respond by claiming that we must at least place the authority of Scripture in its respect to us in some other authority than divine revelation itself. Such authorities might be natural reason or some ecclesial institution. But, much like Culverwell above, Owen insists that such a principle would remove the possibility of genuine self‐testimony by God:

If God reveal himself to us, it must be by means; and if those means may not be understood to reveal him, unless they are testified unto from somewhat else, God cannot reveal himself to us. (1659, 36)

Owen's argument seems to be that, if Scripture cannot show itself to be the authoritative revelation of God, then it must have some other ground of its authority. But if it has some other ground, then we may ask whether that ground can be self‐sufficient as the means of Divine self‐testimony. If yes, then so can Scripture and the internal witness of the Spirit; if no, then we face an infinite regress with regard to the source of authority (in respect of us) of God's revelation. Either God can speak through the kind of means he has ordained, or God cannot carry out self‐testimony at all. ²¹

But Owen also holds that reason has a legitimate role both in mundane moral matters and as a natural light that points beyond itself toward the Creator (1659, 42). Quoting the passage that constituted the Cambridge Platonists’ key text, Owen claims:

There is a Light in Nature, which is the Power of a Man to discern the things of Man. An Ability to know, perceive and judge of things natural. It is that Spirit of a Man which is the Candle of the Lord … Prov. 20.27. ([1677] in Helm 1999, 168)

For Owen (like Culverwll and Turretin), the lux gloriae framework provides a check against making this natural light either the ultimate ground or the noetic horizon of revealed mysteries. Owen's position reflects the lux gloriae framework in insisting that the light of revelation is not a species of the natural light but rather discloses truths (notably, the Trinity, Incarnation, and resurrection of the body) that are above natural reason ([1677] 1850–55, Vol. 4, 85). However, the supernatural light does not destroy the proper exercise of natural reason—but perfects and completes it (1717, 150–51). Like Aquinas before him, Owen claims there is a threefold hierarchy of lights in humankind. God gives above the natural light both a “light of Grace” and a light of glory (1717, 151). The light of grace is a function of divine generosity in revealing to us divine truths in earthly life. But the light of glory transcends the light of grace even as the light of grace transcends the light of nature. Thus, the vision of God in the light of glory is known to be our final end, even as its positive nature remains mysterious. ²²

Owen does make an innovation to this lux gloriae framework, insofar as he focuses more on Christology in his account of beatitude than perhaps any previous thinker in this tradition. For Owen claims explicitly that the vision of God in the light of glory is always mediated through the vision of Christ: “the Blessed and Blessing Sight which we shall have of God, will be always in the Face of Jesus Christ” (1717, 12). ²³ Accordingly, deiformity (or likeness to the deity) is, for the human creature, only ever conformity to Christ.

However, Owen's framework provides just the same noetic bulwarks as do those of Aquinas, Culverwell, and Turretin: the aporia between the natural light and supernatural light will be transcended through the vision of God in the lux gloriae. This is especially clear in Owen's claim that, in the light of glory, the positive nature of the Incarnated Son will be disclosed to human beings. A truth that was revealed but incomprehensible on earth shall be seen above with a “vision…intellectual.” And, although the person of Christ will be the object of the beatific vision, the light of glory will not be limited to sight of merely the human nature of Christ. Rather, the light of glory will allow human beings to see “his Divine Person as that nature subsisteth [in his human nature]” (1717, 145–46). That is, the intellectual vision in the light of glory will remove the veil over the mystery of the Incarnation by a divine gift of intellectual sight (the gift of a “direct, intuitive, and constant… Visive Power”) (1717, 146–47). But to claim insight into this divine mystery (or the light of glory) in this life is ruled out categorically. The light of nature cannot positively know the mystery of Incarnation—or any other chief mysteries of the faith.

These three figures, representing as they do the Reformed tradition in different institutional contexts (Cambridge, Geneva, Oxford), agree in their core attitudes to reason and the Scriptural mysteries. Reason has a moderate function, without collapsing into rationalism. Revealed truths are supra‐rational (but not against reason), and they do not abrogate all proper use of reason in mundane matters or even religious assent. And for these figures, no less than Aquinas, the promise of the lux gloriae preserves the transcendent noetic horizons of Christian theology. The framework prevents the move toward an immanent concordism. These figures thus provide a vital counter‐example to the notion that the choice in Reformed circles of the seventeenth century was between the emerging rationalists and fideists.

The Rise of Immanent Concordism in Mainstream Theology

How then did Scriptural reason become naturalized (or immanentized) such that Scriptural mysteries were put increasingly into a competitive relationship to natural reason? Explaining this transition (in terms of providing historical causes) is beyond my scope here. But I will describe what I take to be some central features of the change. First, the autopistia tradition was undermined in some figures of the mid‐seventeenth century and late seventeenth century. For instance, although he generally asserted that assent to revelation was a form of assent to testimony, there are places where the philosopher Henry More suggests that reason is the final grounds of assent to Scripture as revealed. For instance, More suggests in the Enthusiasmus Triumphatus that supposed revelations must be grounded in “Common notions… the Evidence of outward Sense, or else a clear and distinct Deduction from these”; otherwise they lack warrant altogether (More 1662). ²⁴

Even otherwise Reformed theologians began to emphasize probabilistic arguments as the grounds of certainty in Scripture. Richard Baxter (who certainly insisted that there are divine mysteries) comes near to suggesting reason is the proper grounds of assent to Scriptural mysteries. In his efforts to persuade others of the truth and reasonableness of the Christian revelation, Baxter claims that the Incarnation “is a thing which no man is bound to believe, without very sound evidence to prove it. God hath made Reason essential to our Nature: it is not our weakness, but our natural excellency” (1667, 259). The Anglican Bishop Francis Gastrell (1662–1725) goes even further. The largely conservative theologian astonishingly claims in a 1699 work: “I shall endeavor to establish the Certainty of the Christian Religion, by proving the truth of all the principal Matters of Fact contained in the New Testament” (1699, 4). Absent is the original Calvinist emphasis on divine self‐testimony as the independent and proper ground of certainty.

But the philosopher John Locke's treatment of the grounds of assent to revelation is perhaps the most influential of the period. Locke does suggest in the Essay that divine testimony is the proper way of conceiving of revelation ([1689] 1975, sec. IV.xviii). ²⁵ And Locke insists that “Revelation, where God has been pleased to give it, must carry [assent], against the probable Conjectures of Reason” ([1689] 1975, 694). He even allows that there are revealed propositions above reason. However, it is the faculty of reason that alone must judge whether or not a proposition is revealed ([1689] 1975, 694). Accordingly, there does not seem to be any aspect of assent to revelation that is irreducibly fiduciary, rather than based finally upon probabilistic reason ([1689] 1975, sec. IV.xviii.6).

The lux gloriae doctrine was also marginalized in certain figures of the seventeenth century. Henry More was trained in the Reformed Cambridge of the first half of the seventeenth century. However, he seems to have moved away from the notion that the reconciliation of reason and divine revelation is deferred until the vision of God in the light of glory. According to More, revealed mysteries are not only intelligible in this life but are also seen as certain through rational contemplation. In an elusive passage at the beginning of the Grand Mystery of Godliness, More writes that, with regard to the mysteries:

there is afterward a clearer manifestation and a fuller satisfaction, and the μύστης [initiate] become ἐπόπτης or ἔφορος [overseer], being now more fully ascertained of the Truth which he did but obscurely apprehend before. From which Clearness and Certainty of the thing represented, there necessarily arises a full and free assent of the Understanding… (1708, 1)

There are striking resonances with the Socinian notion that revealed truths become fully intelligible after their revelation. Despite this formal similarity, the Platonic tradition is a more certain and central inspiration for More than the Socinian theologians. As Dougles Hedley notes, More is drawing upon the language of the Orphic, Pythagorean, and Platonic conceptions of mystery. ²⁶

What is centrally important for our purposes is that More suggests that the initiate into the Christian religion can in this life (through the exercise of philosophical contemplation) pierce the revealed mysteries sufficiently to clearly perceive their intrinsic intelligibility. ²⁷ This happens not, it seems, through a final revelation at the lux gloriae but through the gradual ascent of the intellect toward God. More's aim in the Grand Mystery was to lead the reader forth into the perception of such intelligibility. Admittedly, More's emphasis certainly can provide an important check on certain tendencies toward obfuscation in Christian theology, and his combination of piety and philosophical reflection is sincere. But More's treatment of certain Scriptural mysteries resulted in a controversial level of rational revision. ²⁸ When challenged about these rationalizing tendencies, More responded with the Apology of 1664. Far from acknowledging the incomprehensibility of revealed mysteries, the Apology further emphasized the positive and evident concord between reason and revelation. More suggests, for instance, that one should choose for the articulation of the Christian religion principles that “will prevent or answer the greatest Objections the Atheist can excogitate.” These principles are, in More's judgment, those of “Cartesianism and Platonism” (1664, 486). More's insistence on positive concord between reason and faith flows from these Platonic convictions.

Like More, Locke was educated in a deeply Calvinist context. He accepted that there were some revealed propositions above reason. So, one might expect his position to bear some affinity to the lux gloriae framework. But Locke's outlook on this matter seems to be closer to the Socinian position than to the Reformed one. That is, Locke suggests that propositions above reason are merely those “whose Truth or Probability we cannot by Reason derive from those Principles [of reason]” ([1689] 1975, sec. IV.xvii.§23). ²⁹ Locke's adoption of this minimalist sense of supra‐rational propositions constituted a displacement of the transcendent frame of reason's exercise. Perhaps predictably, Locke at points seems to imply that traditional mysteries ought to be rejected (or reinterpreted) because they have not been shown to be coherent. For instance, Locke's treatment of personal identity implies a rational revision of the received doctrine of the resurrection of the body. For Locke insists that the identity of human bodies “consists … in nothing but a participation of the same continued Life” ([1689] 1975, 331–32). That is, there is no reasonable framework for the identity of the body across time except continuous actual existence, and (as Stillingfleet notes in his controversy with Locke) this implies that Locke has no framework to allow for the resurrection of the same body (1698, 32–33). Locke's deflated sense of supra‐rational truths seems to be directly impinging on the received Scriptural mysteries. From the perspective of the earlier Reformed (as well as the Thomists), the light of glory is being displaced by the light of nature; transcendent noetic horizons have begun to be brought down to earth.

Conclusion

I have argued that several major figures of seventeenth‐century Reformed thought articulate a sophisticated picture of the relationship between reason and Scriptural mysteries. Doubtless many important questions remain. Centrally, it must be asked of both Thomist and Reformed authors: how does one know which propositions are supra‐rational (rather than irrational)? I have not attempted here to answer such questions or to defend the rationality of eschatological concordism.

However, I have argued that the Reformed outlook is neither fideistic nor a radical break from Medieval accounts of reason and Scriptural mysteries. Rather, although the Reformed outlook emphasizes divine self‐testimony as a proper ground of assent, this does not collapse into the actual unintelligibility of revealed mysteries. The Reformed outlook avoids fideism because it emphasizes the transcendent frame of all application of reason to revealed mysteries. Indeed, the Reformed emphases show that these thinkers were not shallow Biblicists but were engaged with both traditional doctrinal categories and received philosophical frameworks. Although Scripture became highly contested after the Reformation, the Reformed emphasis on the light of glory (and on revelation as divine testimony) shows that they shared with Thomists central intellectual frameworks for understanding Scripture. ³⁰ Therefore, the source of the rationalistic (or immanentizing) theological tendencies of the seventeenth century should be located elsewhere than supposed fideistic shortcomings of Reformed thought. I have suggested that the immanent concordism in Socinian theology—as well as Platonic emphases in figures like Henry More—are more plausible early sources of the naturalization of Scriptural reason.

Acknowledgments

I am thankful to Magdalena Fletcher, Mandy Marvin, and the staff at the Cambridge University Library for helping with access to texts during Covid‐19 restrictions. I am grateful as well to Douglas Hedley and the Cambridge Centre for the Study of Platonism, where I presented initial reflections on this topic. I would also like to thank Alden McCray for feedback on a draft. Remaining shortcomings are my own. Research for this article was made possible by a Grant from the Templeton Religion Trust. The views expressed here do not necessarily reflect those of the Templeton Religion Trust.