Prolegomena (systematic theology)

“The secret things belong to the LORD our God, but the things that are revealed belong to us and to our children forever, that we may do all the words of this law.”

— Deuteronomy 29:29 (ESV)

Prolegomena (“things said beforehand”) is the introductory locus of a systematic theology, treating theology’s own foundations before its doctrinal content. It identifies two principia: God himself, the ground of all truth about him (principium essendi), and Scripture, the means by which he is savingly known (principium cognoscendi).¹ It also distinguishes God’s own infinite self-knowledge, archetypal theology, from the finite, revealed knowledge creatures receive of him, ectypal theology.²

Confessional Witness

The 1689 Second London Baptist Confession has no chapter titled “prolegomena” or given over to theological method as such. Its opening chapter, “Of the Holy Scriptures,” matches the Westminster Confession (1646) and the Savoy Declaration (1658) in substance,³ and states the confession’s own answer to prolegomena’s central question, the principium cognoscendi:

“The Holy Scripture is the only sufficient, certain, and infallible rule of all saving knowledge, faith, and obedience, although the light of nature, and the works of creation and providence do so far manifest the goodness, wisdom, and power of God, as to leave men inexcusable; yet are they not sufficient to give that knowledge of God and his will which is necessary unto salvation.”⁴

By naming Scripture the “only sufficient, certain, and infallible rule,” the confession settles the same question Reformed orthodoxy treated at length under prolegomena: not reason, church tradition, or an inward light, but Scripture alone as the ground on which saving theology rests.

Biblical Basis

Scripture distinguishes what God has hidden from what he has revealed (Deut. 29:29). Paul draws the same line around God’s own self-knowledge: “who knows a person’s thoughts except the spirit of that person… So also no one comprehends the thoughts of God except the Spirit of God” (1 Cor. 2:11), adding that believers “have received… the Spirit who is from God, that we might understand the things freely given us by God” (1 Cor. 2:12). Isaiah names the same gap between God’s own thoughts and human thought directly: “my thoughts are not your thoughts, neither are your ways my ways… so are my ways higher than your ways and my thoughts than your thoughts” (Isa. 55:8-9). What God does disclose, however, is sufficient for its purpose: Scripture is “breathed out by God and profitable for teaching… that the man of God may be complete, equipped for every good work” (2 Tim. 3:16-17).

Historical Development

Patristic and medieval foundations

Anselm of Canterbury stated a rule for theology’s own procedure that later Reformed prolegomena assumed: faith comes first and understanding follows from it, not the reverse. Anselm did not seek to understand so that he might believe; he believed so that he might understand, since without believing first he would not come to understand at all.⁵ He drew out the same order elsewhere: the Christian ought to advance through faith toward understanding, not approach faith through understanding, and if understanding fails, faith is not for that reason to be abandoned.⁶

Reformed orthodoxy: two principia, archetypal and ectypal theology

Seventeenth-century Reformed scholastics developed prolegomena into its own fixed set of questions. Francis Turretin opened his own Institutes of Elenctic Theology by placing the question of theology’s necessity immediately after its principle: “As the word of God is the sole principle of theology, so the question concerning its necessity deservedly comes before all things.”⁷ He distinguished the principium essendi, God as the object of theology, from the principium cognoscendi, Scripture as the means of knowing him,⁷ a distinction Edward Leigh states in the same terms: “Principium essendi in Divinity, is God the first Essence; Principium cognoscendi, the Scripture, by which we know God, and all things concerning him.”⁸

Alongside this, Reformed orthodoxy sharpened the archetypal/ectypal distinction into its classic form. Petrus van Mastricht’s own prolegomena volume divides ectypal theology, in turn, into the theology of those in heaven, who already comprehend, and the theology of pilgrims still on earth, whether natural or revealed, and insists that revealed theology “does not exclude natural theology, but includes it just as a larger quantity includes a smaller one.”⁹ The distinction was never meant to leave theology with a mere copy unrelated to its original: ectypal theology is genuinely derived from, and stands in a real though creaturely proportion to, God’s own archetypal knowledge.¹⁰

Reformed scholastics also asked whether theology itself is theoretical or practical. Leigh reports the schoolmen divided on the question and sides, through Wendelin, with the practical answer, “because the Scripture, which is the fountain of true Divinity, exhorts rather to practice then speculation.”² Mastricht answers the same question in his own definition: theology “is the doctrine of living, and of living for God, and for God through Christ.”¹¹

Rationalism and the Schleiermacherian turn

Friedrich Schleiermacher relocated theology’s whole foundation from Scripture to religious consciousness. On his account, religion is a form of feeling grounded in “our constitutional God-consciousness,” an intuition of God on the intellectual side and a “feeling of absolute dependence” on the emotional side, so that “the common Christian consciousness of the Church” becomes theology’s last court of appeal, “and not the Scriptures.”¹² Archibald Alexander Hodge answered that this account cannot supply what a remedial religion needs: Christianity “rests upon certain historical facts, which must be known in order to be effective, and which can be authoritatively made known only by means of a supernatural revelation,” something no intuition of feeling can reach.¹²

Opposing Views

Charles Hodge organized the historic answers to prolegomena’s central question, the rule of faith, into four positions.

Rationalism

Rationalism assigns reason undue authority in matters of religion, ranging from a Deistic form that denies any supernatural revelation and makes “reason both the source and ground of all religious knowledge and conviction,” to a milder form that accepts a revelation but subjects its content to reason’s own prior judgment of what can be true.¹³

Mysticism

Mysticism locates the rule of faith in an inward light rather than an outward, written revelation, whether the Quakers’ doctrine of a “general inspiration” given to every believer or Schleiermacher’s later doctrine of religious feeling.¹⁴

Romanism

Romanism admits an objective, supernatural revelation but holds that it is “partly written and partly unwritten,” Scripture together with church tradition, with the church itself made “an infallible teacher” to determine the canon, interpret Scripture’s meaning, and settle which traditions are divine.¹⁵

The Protestant rule of faith

Against all three, the Protestant rule of faith holds, in Hodge’s words, that “all Protestants agree in teaching that ‘the word of God, as contained in the Scriptures of the Old and New Testaments, is the only infallible rule of faith and practice.’”¹⁶

Objections and Responses

The archetypal/ectypal distinction leaves human beings with only a copy of theology, not real knowledge of God. Ectypal theology is genuinely derived from God’s own archetypal self-knowledge and stands in a true, though creaturely, proportion to it rather than an arbitrary or merely verbal one.¹⁰ Certainty in theology does not wait on an independent rational proof of that proportion: Scripture’s truth is grasped in the believing act itself, “through faith to understanding,” since revelation becomes the believer’s own knowledge only as an act of consciousness, namely faith.¹⁷

Treating theology as a science alongside philosophy subordinates revealed truth to categories of proof and system foreign to Scripture’s own aim. The Reformed scholastics who systematized prolegomena answered this by making theology’s own end practical rather than merely speculative: Scripture itself “exhorts rather to practice then speculation,”² and theology is most properly defined not as a set of propositions to be proved but as “the doctrine of living for God, through Christ.”¹¹ Its speculative content, the doctrine of God and his works, serves that practical end rather than displacing it.

Related Doctrines

References

Herman Bavinck, Reformed Dogmatics: Abridged in One Volume, ed. John Bolt (Grand Rapids: Baker Academic, 2011), chap. 1, “Dogmatic Theology as a Science”: “The foundations of faith are twofold: the external and internal, the objective and the formal, revelation and faith. These two topics are the proper subject matter of theological prolegomena.” ↩
Edward Leigh, A Systeme or Body of Divinity (London: A. M. for William Lee, 1654), 2: “Theology or Divinity is two-fold, either first, Archetypal, or Divinity in God, of God himself, by which God by one individual and immutable act knows himself in himself, and all other things out of himself, by himself. Or second, Ectypal and communicated, expressed in us by Divine Revelation after the Patern and Idea which is in God.” ↩ ↩² ↩³
Micah John McCormick, “Historical Survey,” in “The Active Obedience of Jesus Christ” (PhD diss., The Southern Baptist Theological Seminary, 2010), 68: “The Savoy Declaration (1658) and the London Baptist Confession of Faith (1689) are explicit in their affirmation of active obedience. Both are patterned after the WCF and retain the vast majority of the WCF’s wording.” ↩
The Second London Baptist Confession of Faith (1689), chap. 1, “Of the Holy Scriptures,” para. 1. ↩
Anselm of Canterbury, Proslogion 1, quoted (Latin) in Charles Hodge, Systematic Theology, vol. 1 (New York: Charles Scribner and Company, 1871), chap. IV, “Mysticism,” 76. ↩
Anselm of Canterbury, quoted (Latin) in Hodge, Systematic Theology, 1:76. ↩
Francis Turretin, Institutes of Elenctic Theology, vol. 1, First through Tenth Topics, ed. James T. Dennison Jr., trans. George Musgrave Giger (Phillipsburg, NJ: P&R, 1992), 2.1.1 (1:55), quoted in Alex Charles Tibbott, “Turretin and Classical Theism,” in “De Impassibilitate Et Satisfactione: An Examination of the Methodological Implications of Trinitarian Classical Theism for the Doctrine of the Atonement” (PhD diss., The Southern Baptist Theological Seminary, 2024), 98. ↩ ↩²
Edward Leigh, A Systeme or Body of Divinity (London: A. M. for William Lee, 1654), 121. ↩
Petrus van Mastricht, Theoretical-Practical Theology, vol. 1, Prolegomena, trans. Todd M. Rester, ed. Joel R. Beeke (Grand Rapids: Reformation Heritage Books, 2018), chap. 1, “The Nature of Theology,” 179. ↩
Steven J. Duby, God in Himself: Scripture, Metaphysics, and the Task of Christian Theology, Studies in Christian Doctrine and Scripture (Downers Grove, IL: IVP Academic, 2019), chap. 1, “Theologia Within the Divine Economy,” 10-57, at 33: “the Reformed point out that ectypal theology and archetypal theology are not equals within a genus of knowledge. Ectypal theology is derived from archetypal theology and only analogically one with it.” ↩ ↩²
Mastricht, Prolegomena, chap. 1, “The Nature of Theology,” 201: “theology is the doctrine of living, and of living for God, and for God through Christ.” ↩ ↩²
Archibald Alexander Hodge, Outlines of Theology (New York: Robert Carter and Brothers, 1879), chap. 3, “Sources of Theology,” 53-55. ↩ ↩²
Charles Hodge, Systematic Theology, vol. 1 (New York: Charles Scribner and Company, 1871), chap. III, “Rationalism,” 34. ↩
Hodge, Systematic Theology, 1:61-104, chap. IV, “Mysticism”; A. A. Hodge, Outlines of Theology, 54. ↩
Hodge, Systematic Theology, 1:104, chap. V, “Roman Catholic Doctrine Concerning the Rule of Faith.” ↩
Hodge, Systematic Theology, 1:152, chap. VI, “The Protestant Rule of Faith.” ↩
Bavinck, Reformed Dogmatics, chap. 6, “Faith”: “The slogan that guides and controls Christian theology is: per fidem ad intellectum (‘through faith to understanding’)… Since all knowledge is mediated through human consciousness, revelation too is known as an act of human consciousness, namely faith.” ↩