Francis Turretin’s Natural Theology: Natural Theology’s Use | John Sweat

by | Dec 22, 2023 | Apologetics, Historical Theology, Systematic Theology

*Editor’s Note: This is the sixth 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:

To read part 2 of 6, click here:

To read part 3 of 6, click here:

To read part 4 of 6, click here:

To read part 5 of 6, click here:

To read part 6 of 6, click here:


Natural Theology’s Use

Having argued that Turretin’s dogmatic conception of natural theology is revealed ectypal theology, the proper uses of his natural theology can be further enumerated. Turretin lists five general uses or ends of natural theology. First, natural theology is a witness to God’s goodness towards unworthy sinners; this is what later theologians call common grace, God leaving a light of revelation for them in nature (Acts 14:16-17; John 1:5). Second, Turretin sees natural theology functioning through natural law as a “bond of external discipline” on men in the world, restraining the corruption of men and upholding order in the world (Romans 2:14-15).  Third, natural theology is the “subjective condition” in which the light of grace appeals (Acts 14:27).[1] Fourth, natural theology incites men to search for clearer revelation (Acts 14:27). And last, natural theology leaves men without an excuse (Romans 1:20).[2]

Carrying these general uses forward, Turretin’s apologetic use of natural theology will be considered in the remaining space of this paper. Turretin, in concert with the Reformed orthodox, understood the limits of natural theology and its place in relation to supernatural theology. True natural theology must be conducted by regenerate reason because God’s natural revelation is determinative of the content and scope of true natural theology.[3] However, the proper conclusion from this is not that natural arguments for God’s existence should be discarded.[4] Rather, the proper conclusion is that such arguments must be regulated by the realization that the unbeliever cannot come to God through reason, and the Christian by the Spirit through the word, can wield faithful reason to press the unbeliever with the testimony of God in natural revelation, silencing their foolishness.[5] Natural arguments do not reveal to the unbeliever what they do not know, but rather calls them to account for rejecting what they clearly know.[6]

Turretin begins locus three asking whether God’s existence can “be irrefutably demonstrated against atheists.” Turretin affirms the question, but before seeking to demonstrate the existence of God contrary to the atheist, he begins with some presuppositions. First, he notes that God holds “the first place in theology and embraces the sum of all saving knowledge.”[7] Second, God is the undisputed “first principle of religion” that is to be taken for granted rather than proved.[8] It is in light of these two presuppositions that Turretin moves to refute the atheist, who madly rejects the implanted knowledge of God within him and closes his eyes to God’s witness in nature.[9] The end of these arguments are not to prove a generic deity, but rather to disarm the atheist objections from nature that God does not exist.[10]

Turretin’s natural arguments are built on four foundational principles: the voice of universal nature (paragraphs six through eleven), the contemplation of man himself (paragraphs twelve through thirteen), the testimony of conscience (paragraphs fourteen through fifteen), and the consent of all mankind (paragraphs sixteen through eighteen). God has so deeply stamped his testimony in creation that he cannot “be wrested” from it “without totally confusing and destroying it.”[11] After expounding these arguments, which he considers sufficient to deal with the atheist, Turretin states that God’s existence is more clearly displayed by the “irrefragable word” which is “inscribed” on the believer’s mind[12] The believer does not need these proofs for God’s existence to have saving faith, but believers do need the proofs as tools to defend and encourage each other in their faith.[13]



Turretin’s natural theology is dogmatically conceived as revealed ectypal theology following Calvin’s two-fold knowledge of God and Junius archetype/ectype paradigm. Some of the secondary literature that attempts to interact with the Reformed scholastics’ natural theology either reads into the Reformed tradition a rationalistic natural theology of the Enlightenment or assumes that the Reformed scholastics’ natural theology is an exact replica of the middle ages. Turretin’s natural theology is developed underneath the heading of an ectypal revealed theology, in light of the Christian faith, and in service to supernatural theology. Natural theology nor reason are a threat to the authority of Scripture. Natural theology is that which can be known about God from natural revelation both through innate and acquired knowledge; the book of natural theology, when situated in service to faith and read in light of Scripture, must not be ignored in the school of God.

Further research could pursue several questions in relation to this topic: Is there a strong distinction between natural revelation and natural theology in Reformed scholasticism? How does Turretin’s natural theology compare to Herman Bavinck’s strong conception of a dogmatic natural theology? Do Turretin’s theistic proofs differ from Aquinas methodologically and formally?


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] The use has been explained in the previous point.

[2] Turretin, Institutes of Elenctic Theology, 1.4.4. These five uses of natural theology demonstrate that Turretin does not distinguish, at least formally, between natural theology and natural revelation. Junius seems to do the same thing throughout his treatise.

[3] Sudduth, “Revisiting the ‘Reformed Objection’ to Natural Theology,” 60-63. Sudduth argues further that Scripture regulates the claims of natural theology, first by beginning with the biblical God as the starting point and second, by Scripture regulating false conclusions about God from natural theology. Sudduth, “Revisiting the ‘Reformed Objection’ to Natural Theology,” 60-63.

[4] Muller, Richard A., Dictionary of Latin and Greek Theological Terms, 358, 363.

[5] Beeke and Smalley give several biblical and Reformed principles that should shape one’s approach to theistic proofs. Beeke and Smalley, Revelation and God, 1:236–241.

[6] Beeke and Smalley, Revelation and God, 1:259.

[7] Turretin, Institutes of Elenctic Theology, 3.1.1.

[8] Turretin, Institutes of Elenctic Theology, 1.3.3.

[9] Turretin, Institutes of Elenctic Theology, 3.1.4.

[10] Beeke and Smalley, Revelation and God, 1:360. Sudduth helpfully shows that a dogmatic natural theology presupposes the existence of God and engages in theistic arguments in nature with the foundation of the Christian faith. Sudduth, “Revisiting the ‘Reformed Objection’ to Natural Theology,” 59–60. The Dutch theologians Herman Bavinck states something similar when he says, “Accordingly, Christians follow a completely mistaken method when, in treating natural theology, they, as it were, divest themselves of God’s special revelation in Scripture and the illumination of the Holy Spirit, discuss it apart from any Christian presumptions, and then move on to special revelation. Herman Bavinck, Reformed Dogmatics: God and Creation, ed by. John Bolt, trans by. John Vriend, vol. 2 (Grand Rapids, MI: Baker Academic, 2004), 74.

[11] Turretin, Institutes of Elenctic Theology, 3.1.5. In regards to the use of natural and philosophical arguments for God’s existence amongst the Reformed scholastic, in light of the archetype/ectype paradigm, it must be kept in mind that there is a distinction between rational arguments and a rationalistic worldview. The former the Reformed scholastics use within the “framework of revelation.” Van Asselt and Dekker, Reformation and Scholasticism: Texts and Studies in Reformation and Post-Reformation Thought, 32. Manning notes further that Plantinga’s objection to natural theology stems from a narrow view of theistic proofs, confusing philosophical arguments for natural. Manning, Russell Re, The Oxford Handbook of Natural Theology, 205–206.

[12] Turretin, Institutes of Elenctic Theology, 3.1.20.

[13] Richard A. Muller, Post-Reformation Reformed Dogmatics: The Divine Essence and the Attributes, vol. 3 (Grand Rapids, MI: Baker Academic, 2003), 170. In a helpful parallel, the word of God is self-authenticating and full persuasion of its divine authority comes by the inward work of the Spirit, yet the Second London confession in chapter one paragraph five gives a list of secondary evidences that testify to the Scripture’s divine character. Theistic proofs function in a similar way to those secondary evidences.

Follow Us In Social Media

Subscribe via Email

Sign up to get notified of new CBTS Blog posts.

Man of God phone

Pin It on Pinterest

Share This