*Editor’s Note: This is the fifth installment in a six-part series called “Francis Turretin’s Natural Theology.” As more installments are released, each part of the series will be linked to each post.

To read part 1 of 6, click here: https://cbtseminary.org/francis-turretins-natural-theology-clearing-the-historical-record-john-sweat/

To read part 2 of 6, click here: https://cbtseminary.org/francis-turretins-natural-theology-john-calvins-influence-john-sweat/

To read part 3 of 6, click here: https://cbtseminary.org/francis-turretins-natural-theology-francis-juniuss-influence-john-sweat/

To read part 4 of 6, click here: https://cbtseminary.org/francis-turretins-natural-theology-natural-theologys-definition-john-sweat/

To read part 5 of 6, click here: https://cbtseminary.org/francis-turretins-natural-theology-natural-and-supernatural-theology-john-sweat/

To read part 6 of 6, click here: https://cbtseminary.org/francis-turretins-natural-theology-natural-theologys-use-john-sweat/

Natural Theology and the Mode of Reason

Having considered the definition of natural theology, the mode of reason and natural theology must be considered. Although Turretin’s focus in his treatment of natural theology is on the postlapsarian state, he briefly notes the discontinuity between man’s natural theology before the fall and after stating, “This [natural theology] was exquisite in Adam before his fall, but is highly disordered in corrupted man.”[1] This comment appears to mirror Junius’s statement, “For either this nature is considered in relation to itself, as it was created by God, or according to the sin that besets it and the corruption that followed the fall of our first parents.”[2] Just prior to this comment in thesis fifteen, Junius spoke of “the natural light of human understanding” functioning “in proportion to the method of human reason,” but natural theology is “common, veiled, imperfect” in man.[3] Man’s reason, which is in part the mode of considering natural theology, is in itself weak and corrupted by sin. Therefore, reason functions in proportion to that reality, rendering natural theology in need of perfection.

Turretin treats the use of reason extensively under questions eight through ten of locus one. Man’s reason is not eviscerated in the fall, but it is rendered corrupt and blind.[4] But Turretin notes that if reason is treated abstractly (in abstracto), it can be considered as sound in fallen man, but if considered concretely (in concreto), then it is antithetical to theology.[5] Nonetheless, Turretin does grant that unregenerate men’s reason can be reliable although fallible in relation to knowledge of first principles. Rays of light still penetrate through the darkness of man’s fallen condition.[6] “If this were not the case, there could be no science, nor art, nor certainty in the nature of things,” writes Gabrill.[7] The issue is not whether man has the capacity to arrive at truth, but whether they can in their fallen condition distinguish between first principles and conclusions.

Turretin does claim, however, that sound reason “restored and enlightened by the Holy Spirit” can make sound judgments.[8] Grabill notes that Turretin’s conception of human reason, “not only indicates a positive use of regenerate natural theology but also simultaneously acknowledges the noetic effects of the fall.”[9] This is a key argument that has been made throughout this paper. The Reformed orthodoxy paradigm of true and false theology grounds true natural theology not in reason generally, but rather in faithful reason that has been renewed by the Spirit.[10]

Natural Theology’s Relationship to Supernatural Theology and Faith

Given the preceding, Turretin situates natural theology as subordinate to supernatural theology for the latter is insufficient for a true knowledge of God or salvation.[11] Turretin is clear that the only way of salvation after the fall comes by way of the revealed word, and that all other false religions, while giving evidence of natural theology (falsely so), are insufficient for salvation yet sufficient for rendering men inexcusable.[12] Muller helpfully notes that assumed in the Protestant orthodox conception of natural theology is that distinction between natural theology and supernatural theology, and they “do not view natural revelation, human reason, or light of nature (lumen naturae, q.v.) considered in its corrupt state apart from supernatural revelation.[13] Ectypal natural theology is not considered apart from revelation or Scripture. Even a positive regenerate natural theology is limited and in need of supernatural theology.

Supernatural theology is “strictly called ‘revealed’ because its first principle is divine revelation strictly taken and made through the word, not through creatures.”[14] Supernatural theology as revealed in the Scriptures is superior to natural theology for it transcends reason and perfects the imperfections of natural theology via “the new light of grace” in contrast to the light of nature in natural theology.[15] Turretin notes that faith presupposes the knowledge of nature.[16] The two are of different classes but not opposed to one another. Turretin writes, “Reason is perfected by faith and faith supposes reason, upon which to found the mysteries of grace.”[17] However, Scripture alone is the principium cognescendi and the ground of the Christian’s assurance.[18] Reason is in service to faith.[19]

Before delineating some of Turretin’s uses of natural theology, his comments in locus one, question four, paragraph three have to be reconciled with this paper’s continual rejection of positing a pre-dogmatic natural theology in Turretin, and at large, in the Reformed tradition. In this question, Turretin states that supernatural theology is built upon natural theology, appearing to argue for a pre-dogmatic model. Turretin does not explain how supernatural theology can be built upon natural theology other than the example he gives: “that there is a God, that he must be worshipped.”[20] However, if what Turretin has said previously is considered regarding faith and reason – that faith presupposes reason and reason is perfected by faith – then it is evident that he is not arguing for a pre-dogmatic conception. On the contrary, Turretin is explaining that the first principles known via nature are built upon by supernatural revelation, not in a pre-dogmatic manner where the former is the necessary foundation of the latter, but rather, in an organic way that recognizes that faith operates within the context of nature.[21] Turretin indicates this in part when he explains that one of the uses of natural theology is that it functions as “a subjective condition in man for the admission of light of grace because God does not appeal to brutes and stocks, but to rational creatures.”[22] Further, Turretin’s placement of natural theology under ectypal revealed theology eliminates the possibility of Turretin arguing for a pre-dogmatic conception here.

About the Author

John Sweat is a marine veteran who serves as one of the pastors at Covenant Community Church in Lake Butler, Florida. He is a husband to Heather and a father to four girls. John has received an MA in biblical studies and an MA in Christian Thought at Gordon Conwell Theological Seminary.

[1] Turretin, Institutes of Elenctic Theology, 1.2.7; 1.3.1.

[2] Junius, A Treatise on True Theology: With the Life of Franciscus Junius, 151.

[3] Junius, A Treatise on True Theology, 145, 147. Shannon, “A Brief Rejoinder to Kevin DeYoung,” 272.

[4] Turretin, Institutes of Elenctic Theology, 1.8.1.

[5] Turretin, Institutes of Elenctic Theology, 1.9.10. Turretin mentions briefly these first principles of natural theology by the light of nature here Turretin, Institutes of Elenctic Theology, 1.4.3.

[6] Turretin, Institutes of Elenctic Theology, 1.9.5.

[7] Grabill, “Natural Law and the Noetic Effects of Sin: The Faculty of Reason in Francis Turretin’s Theological Anthropology,” 268.

[8] Turretin, Institutes of Elenctic Theology, 1.10.1.

[9] Grabill, “Natural Law and the Noetic Effects of Sin: The Faculty of Reason in Francis Turretin’s Theological Anthropology,” 267–268.

[10] Muller, Prolegomena to Theology, 1:282.

[11] Turretin, Institutes of Elenctic Theology, 1.4. Junius speaks of even the need for supernatural theology to perfect natural theology prior to the Fall. Junius, A Treatise on True Theology, 151.

[12] Turretin, Institutes of Elenctic Theology, 1.4.2.

[13] Muller, Dictionary of Latin and Greek theological terms, 263.

[14] Turretin, Institutes of Elenctic Theology, 1.2.7. Joel R. Beeke and Paul M. Smalley, Reformed Systematic Theology Volume 1: Revelation and God, 1:258–259.

[15] Turretin, Institutes of Elenctic Theology, 1.2.7; 1.4.6. Junius, A Treatise on True Theology: With the Life of Franciscus Junius, 143, 151, 160.

[16] Turretin, Institutes of Elenctic Theology, 1.3.10.

[17] Turretin, Institutes of Elenctic Theology, 1.9.5.

[18] Turretin, Institutes of Elenctic Theology, 15.8.6; 15.9.15.

[19] Muller, The Triunity of God, 4:413.

[20] Turretin, Institutes of Elenctic Theology, 1.4.3.

[21] Muller, Prolegomena to Theology, 1:300. Muller writes later, “We must object strenuously, therefore, to the all-too-frequent and utter erroneous claim that orthodox or scholastic Protestant theology generally viewed natural revelation and the natural theology drawn from it as a foundation on which supernatural revelation and supernatural theology can build… Rather supernatural theology, identified not so much as an unnatural or preternatural way of knowing but as a graciously given way of knowing, provides the context in which all other knowledge must ultimately be understood.” Muller, Prolegomena to Theology, 1:310.

[22] Turretin, Institutes of Elenctic Theology, 1.4.4.