Theses on natural theology
Recent Reformed theology has not held natural theology in high esteem, and that for understandable reasons. Enlightenment thinkers (Catholic, Protestant, and secular) often treated natural theology as a pre-dogmatic discipline, i.e., as a discipline that could and should be established independently of biblical revelation before turning to biblical revelation to establish the truths of dogmatic theology. In many cases, such an approach also failed to acknowledge the noetic effects of sin for the possibility of natural theology.
Turning to Reformed discussions of natural theology in the early modern period, however, one discovers a platypus. Discussions of natural theology from this period do not fit the categories of Enlightenment natural theology and therefore are less susceptible to recent Reformed criticisms. Here natural theology is not treated as a pre-dogmatic discipline but as a discipline that is dependent upon dogmatic theology for its success. Indeed, the terms of early Protestant natural theology are largely set by biblical commentary on texts such as Romans 1-2 (e.g., Philip Melanchthon, Peter Martyr Vermigli). Here we also discover an acute awareness of the noetic effects of sin upon natural theology, effects which require assistance from the epistemological principles of dogmatics (i.e., Holy Scripture, the Holy Spirit) if they are to be overcome.
Based upon earlier Protestant treatments of natural theology (especially those of Vermigli, Franciscus Junius, Gisbertus Voetius, and Bernardus de Moor), I have come to see the importance of natural theology for a number of spheres of Christian intellectual and practical inquiry. Moreover, I have come to the conclusion that, far from detracting from revealed theology, it is only in giving natural theology its due that we can fully appreciate the true honor and dignity of revealed theology. In partial payment of that debt, I offer the following nine theses on natural theology.
Theses on natural theology
I. Natural theology considers the existence, attributes, and operations of God insofar as they may be known through God's works of creation and providence by means of natural reason. It is "theology" because it treats God and all things in relation to God, the efficient, exemplary, and final cause of all things. It is "natural" because it treats its twofold object under the aspect of natural reason (as opposed to "revealed theology," which treats this twofold object under the aspect of special revelation, on which, see below).
II. Christian dogmatics can and must speak about natural theology for at least three reasons: because Holy Scripture instructs us regarding the character, content, limits, and ends natural theology, because fallen creatures abuse natural reason and suppress the fruits of natural theology, and because God in his grace seeks to restore and perfect human nature, including human reason (Ps 19.1-6; Rom 1.18-32; 1 Cor 1.21).
III. Natural theology may be considered under three aspects: metaphysical, epistemological, and moral.
(1) In terms of metaphysics: natural theology distinguishes the true and living God who is God "by nature" from gods falsely so-called who lack the distinguishing properties of the divine nature (Acts 14.15; Rom 1.19-23; 1 Cor 8.5; Gal 4.8-9). Natural theology also addresses the natures and ends of rational creatures, especially human beings in their moral and social capacities (Rom 1.26).
(2) In terms of epistemology: natural theology addresses the kind of knowledge about God that creatures may obtain through his works of creation and providence by means of natural reason (Pss 19.1-6; 94.8-11; Acts 14.15, 17; 17.22-29; Rom 1.18-20).
(3) In terms of morals: natural theology (or, more precisely, natural law) addresses that which may be known about divine worship and human ethics through creation and providence by means of natural reason (Rom 1.21-32).
IV. Though operative since the creation of the world (Rom 1.20), natural theology functions in different ways in humanity's fourfold state of nature (before and after the fall), grace, and glory. Discussions of natural theology must be alert to these differences.
(1) In the state of nature before the fall, natural theology functioned with integrity in concord with and subordination to revealed theology (Gen 2.19-20, 25).
(2) In the state of nature after the fall, natural theology is severely corrupted but not absolutely extinguished (Acts 14.17; Rom 1.18-32).
(3) In the state of grace, natural theology is healed under the tutelage of Holy Scripture and through the Holy Spirit's work of regeneration and renewal (1 Cor 11.14).
(4) In the state of glory, natural theology will give way to the beatific vision (1 Cor 13.12; Rev 22.4). In comparison to the beatific vision of God, natural theology is like "the eyes of the night owl before the sun" (Gisbertus Voetius).
V. Natural theology may be distinguished from revealed theology in terms of principles and content.
(1) In terms of principles or sources:
(i) The principles of natural theology are both external and internal (Rom 1.19-20, 32). The external principles of natural theology are God's works of creation and providence. The internal principle of natural theology is human reason, which discerns the natures of God and creatures through sense experience of God's works of creation and providence and by means of common notions implanted by God in the human mind.
(ii) The principles of revealed theology are both external and internal as well. The external principle of revealed theology is the infallible Word of God: incarnate in Jesus Christ, ministered by prophets and apostles, and inscribed in Holy Scripture (Heb 1.1-4; 2.1-4; 2 Tim 3.16). The internal principle of revealed theology is Spirit-engendered faith, the renewed disposition of reason which receives and interprets God's infallible Word (1 Cor 2.6-16).
(2) In terms of content:
(i) Natural theology (along with natural law, its ethical counterpart) teaches that God is and what God is, the nature of human beings, the moral law, and general principles regarding well-ordered human society, both familial and civil (Rom 1.18-32).
(ii) Revealed theology teaches with greater clarity the truths of natural theology. In addition to this, revealed theology teaches truths that are hidden to natural theology: who God is (the Holy Trinity), the person and work of the mediator (Christology and soteriology), the means of covenant fellowship with God through Christ (covenant theology), and specific principles regarding the nature, ministry, and worship of the church (ecclesiology) (Job 28; Matt 11.25-27; 1 Cor 3.5-10; Eph 3.4-5; Col 1.25-27).
VI. Natural theology is related to revealed theology in three ways.
(1) Natural theology and revealed theology share the same ultimate source, the Father of lights (James 1.17), and derive knowledge from their diverse principles through participation in the same Logos (John 1.9).
(2) Because they flow from the same ultimate source and participate in the same Logos, natural theology and revealed theology, though distinct, are by nature concordant. They are discordant only by accident through the blindness and corruption of sin.
(3) Natural theology is subordinate to revealed theology. Natural theology cannot serve as norm or judge for revealed theology (Gen 3.6; 1 Cor 2.15). Revealed theology is the light in which natural theology sees light and by which it is perfected (Psalm 19).
VII. Natural theology is always intrinsically incomplete and therefore incapable of producing religion that is pleasing to God (Acts 17.23).
(1) In the state of nature before the fall, the incomplete character of natural theology was addressed by God through the covenant of works.
(2) In the state of nature after the fall, the incomplete character of natural theology is addressed by fallen sinners through the construction of idols and false religion.
(3) In the state of grace, the incomplete character of natural theology is addressed by God through the covenant of grace in the church.
VIII. The ends of natural theology may be differentiated in relation to its various subjects east of Eden.
(1) Natural theology refutes unbelievers by exposing their willful suppression of the truth that God has made manifest through creation and providence (Acts 17.22-30).
(2) Natural theology encourages believers by confirming through reason truths otherwise received by faith.
(3) Natural theology (along with natural law) provides general principles for the ordering of human society in its ecclesiastical form and assists the preservation of human society in both familial and civil forms. In terms of its latter service, natural theology prevents society's absolute free fall into nihilism, with varying degrees of success, even as it fails to raise society up to the wisdom that belongs to the communion of saints due to the limited nature of its principles and content.
IX. We may err in excess or in defect in relation to natural theology.
(1) We err in excess when we make natural theology the norm and judge of revealed theology, when we exaggerate natural theology's potential with respect to the knowledge of God (e.g., the triunity of God), when we ignore the weakness and futility of human reason vis-à-vis natural theology after the fall, or when we regard natural theology as sufficient for true religion.
(2) We err in defect when we deny the possibility and benefit of natural theology or when we posit absolute metaphysical discord between natural theology and reveal theology.
 I am grateful to Laurence O'Donnell for helping craft this definition of natural theology.