NATURAL THEOLOGY (THEODICY). - It is the knowledge that man can have of the existence and nature of God (v.) by means of reason (v.).
It is distinguished from revealed and supernatural theology because the latter proceeds from the principles of Revelation (v.), whereas natural theology is founded on the principles of reason and starts from the data of experience (v.). This division into two theologies (natural and supernatural) is rather recent, because the so-called natural theology, insofar as it sets forth the rational knowledge of the First Principle of things, belongs to metaphysics (v.) as its completion. The principal object of natural theology can be indicated in three groups of questions in the following order: a) the existence of God; b) the nature of God and knowledge of the attributes of God; c) providence, or the solution of the problem of evil (v.). Evidently these are problems bound up with one another, so that one is not permitted to stop at one while excluding or ignoring the other; on the other hand, it is clear that the most frequent reason for theoretical and practical atheism (v.) is the difficulty of reconciling the existence of a personal God, and therefore his goodness and providence, with the existence of physical and moral evil. The term "theodicy" in fact, which in Neoscholasticism often is equivalent to that of natural theology, was adopted by Leibniz (v.) to confront the difficulty of the problem of evil, but it met with the criticism of Kant (v.).
I. TERMINOLOGY
The term natural theology (theologia naturalis) is first encountered in the pontiff Q. Mucius Scaevola, consul in 95 B.C., and is then taken up again by Varro (according to the testimony of St. Augustine; cf. De civit. Dei, IV, ch. 27; VI, chs. 2-10; VIII, ch. 5) in the encyclopedia entitled Antiquitates rerum humanarum et divinorum in 41 books, of Stoic inspiration. Varro distinguishes a threefold theology: mythical or fabulous, physical or "natural," and civil, that is, political. "Mythical" theology is the work of the poets, but unworthy of the divinity; natural theology is reserved for philosophers; civil theology concerns the religion of the State (De civ. Dei, loc. cit., ch. 4, 1-2). However, natural theology, that is, the doctrine of the philosophers concerning the divinity, is judged superfluous and even harmful because it can turn the people away from civil religion and thus harm the State. St. Augustine notes instead that natural, that is, philosophical, theology has shown the impropriety of mythology and has introduced a truer and more worthy notion of God as the Supreme Principle, understood as the Father of all men and not the name of a particular people or nation as civil theology claimed (cf. the discreet praise of the philosophers: ibid., II, 7).
II. CENNO STORICO
Understood as the conception of the divinity that is elaborated by philosophical thought, natural theology developed in accordance with the peculiar orientations of the various schools in their historical development.
The term theology (θεολογία) is applied by late Hellenism (Damascius) to Orpheus, who "derived the first Principle from Night" (frg. B 12: H. Diels, Fragm. d. Vors., I, 5th ed., Berlin 1934, p. 10, 27). Plato, in the sketch of natural theology in the De Republica, admonishes the poets to adhere to suitable patterns when they must represent the divinity (οἱ τύποι περὶ θεολογίας), namely that God as he is (οἷος τυγχάνει ὁ θεὸς ὤν) is essentially good and cannot be the cause of any evil: evil comes from other causes (Resp., II, 18, 379 a-c). In Aristotle θεολογία can indicate either poetic-mystical speculation (cf. Meteor., II, 1, 353 a 35), or the concluding part of theoretical philosophy that treats of the First Principle "separate and immobile" (ἐπιστήμη θεολογική: Met., XI, 7, 1064 a 33 ff.). In the first sense Aristotle opposes those first poets (οἱ πρώτοι θεολογήσαντες) who indulged in anthropomorphic images, to the first who set about truly philosophizing (οἱ πρώτοι φιλοσοφήσαντες); that is, he posits the opposition between those who accommodated themselves to the popular mentality and those instead who followed the rigorous discipline of thought (cf. ibid., I, 2, 983 b 6, 11, 28). To that first category belong Orpheus, Pherecydes, Homer, Hesiod... (ibid., III, 4, 1000 a 9. For the texts, v. H. Diels, Fragm. d. Vors., ed. cit. III, Index, 204 b. 23-26). Xenophanes can therefore be considered the first "metaphysical theologian" who expressly affirms the unity of God (the One), the "nature most excellent and noble of all": τὸ δὲ πάντων κράτιστον καὶ ἄριστον θεός (H. Diels, A 31; ed. cit., I, p. 121, 31) and the fundamental ontological opposition between God and the world: God is the One, the Omnipotent, the Immutable, the Eternal, who rests in himself... «αἰεὶ δ'ὲν ταῦτῳ μίμνει χινοόμενος οὐδέν (H. Diels, I, ibid., B 26, p. 135, 10). A step forward seems to be taken by Parmenides, who concentrates on the mystery of being and presents the One as an object of religious veneration, and, even if God is not expressly endowed with personality, the concreteness of his language about the experience of truth reveals a genuine religious experience (cf. frg. B 6, 6; H. Diels, ed. cit., I, p. 233, 4). Heraclitus celebrates the epiphany of God in the activity of nature: He is "day and night, winter and summer, war and peace, satiety and hunger" (frg. B 67; ibid., I, p. 165, 8 ff.), present everywhere, but has his seat in fire (Aristotle, De part. anim., I, 5, 645 a 17). It should be noted that the majority of the sophists, accused of "atheism" (v.), in reality rather criticized the crude anthropomorphic conceptions of the poets and the self-interested state religion of the politicians (cf. the trial of Socrates). One must therefore recognize a continuity in the development of natural theology in Greek thought, which from the beginning appears dominated by the problem of God. In the great Socratic systems the problem of the relationship between the divinity and evil explicitly emerges, but in reality God is ignorant of evil: God, for Greek thought, represents the sphere of rationality. Evil is referred, if physical, to matter, and if moral, to ignorance (Plato) and to contingency (Aristotle). It is with Stoic and Neoplatonic philosophy that natural theology obtains its systematic foundation. The Stoic treatment of natural theology rests on the principle of having indicated in God the actuality as λόγος of nature, while passivity belongs to matter. The principle of activity is the "artificer fire" (πῦρ τεχνικόν) that penetrates nature through and through; it is not fire that burns and consumes, but vital fire that preserves, nourishes, sustains all things and furnishes all things with meaning, according to the saying of Virgil: "Spiritus intus alit, totamque infusa per artus mens agitat molem et magno se corpore miscet" (Aeneid, VI, v. 726 ff.). Such omnipresent and omnipotent fire is God, the supreme mind: it contains within itself the "seminal reasons" (λόγοι σπερματικοί) according to which all things, by necessary preordination (καθ'εἰμαρμένην), are generated; and it is spirit (πνεῦμα) that extends through the whole universe and takes various names in the whole of matter (Aetius, Placita, I, 7, 33; H. Diels, Dox. gr., 2nd ed., 305, 15 f.). Therefore the Stoics identify
God with the reality of the world. He is "an immortal animal, rational, perfect, or rather intellectual in the possession of happiness, preserved as much as possible from every evil, who has providence of the world and of the things that are in the world." But he does not have "human form" (ἀνθρωπόμορφος); he is the artificer (δημιουργός) of the whole and as the father of all (ὥστερ πατὴρ πάντων; Diogenes Laertius, VII, ch. 1); he is called Δία (Jupiter), because through (διά) him all things are, and Zeus (Ζῆνα) insofar as he makes all things live (ζῆν). Therefore, affirms Zeno, the substance of God is the universe-whole and the sky. This physical immanence of the divinity constitutes the perfect rationality of the cosmos, which in turn explains the Stoic conception of "fate" and which is the foundation of the imperturbability of the sage. This metaphysics of natural theology had its opening in the theory of knowledge. The Stoics place the starting point of knowledge in the first "innate knowledges" (ἔμφυτοι προλήψεις): they are not innate ideas, but derive immediately from experience through a "natural disposition" that makes man akin to God, and therefore the notion of God and religion belong to the essence of man. At this point the unity of the human race is welded together: all, Greeks and barbarians, believe in the divinity by virtue of the same notions, offer sacrifices, pray, direct vows. The principal arguments for the existence of God are, for Cleanthes, the predictions of the oracles, the beauty of the stars, the order and hierarchy of beings that show themselves guided by an immanent finality. The corruption of the concept of God in polytheism arose from the personification of natural forces, from the passions, from the morbid fantasy of the poets... and in general from the incapacity to raise oneself to contemplate God in the Whole of the Universe (cf. Aetius, Placita, I, 6: πόθεν ἔννοιον ἔσχον θεῶν ἐνθρώποι; H. Diels, Dox. gr., 2nd ed., p. 294 ff.). In this grandiose speculation a place of privilege was held by Posidonius, whose (lost) treatise Περὶ τῶν θεῶν was the source of Book III of the Contra dogmaticos of Sextus Empiricus and of the De natura deorum of Cicero, as well as of the already cited Virgil (cf. K. Reinhardt, Poseidonios, Munich 1921, p. 208 ff.). Posidonius makes the synthesis of the theology of Plato and Aristotle with the Stoic one, also welcoming Pythagorean elements: "God is intelligent and fiery spirit (πνεῦμα νοερὸν καὶ πυρώδες) that has no (corporeal) figure, that turns to what it wills and communicates a likeness of itself to all things" (H. Diels, Dox. gr., 2nd ed., p. 302 b).
A doctrine characteristic of Poseidonius's anthropological theology is the conception of man as a "combination" (συνδεσμός) and circle of all things; man is like the bond between corruptible reality and the divinity, so that all things are held in a single, uninterrupted bond (the cosmic "sympathy") from the inorganic world, to plants, to animals, up to God: this is the most sumptuous historical form of a natural theology in its original sense (cf. K. Reinhardt, Kosmos und Sympathie. Neue Untersuchungen über Poseidonios, Munich 1926, especially p. 111 ff.). The influence of Poseidonius is notable also on the Hellenistic Jew Philo (v.) and on Christian writers themselves such as Origen, the Cappadocians, Nemesius of Emesa and Calcidius, who seem to develop the richness of the Christian conception upon the fabric of the Stoic conception (cf. H. Koch, Prousia u. Paideusis, Studien über Origenes u. sein Verhältnis zum Platonismus, Berlin and Leipzig 1932, Anhang, p. 216 ff.). The speculations of Neoplatonism, from Plotinus to Proclus, constitute a natural theology that absorbs the whole of philosophy: the "divine" is in fact considered there not only in static form (like Plato's "ideas") but in relation to the becoming of the real, which is articulated in the processes of emanation of the hypostases (the One, the Intellect, the Soul... in Plotinus; the Unparticipated, the participations and the participants in Proclus). The recondite and mystical side of Greek natural theology developed in parallel with philosophy, and with alternating movements of approach and repulsion toward it, in the Orphic-Pythagorean doctrines on the "theogonies" (cf. M. J. Lagrange, Critique historique. I. Les mystères. L'orphisme, Paris 1937, p. 119 ff.).
Natural theology reaches its fulfillment under the influence of Revelation in patristic and medieval thought. Recent research into the Stoic and Neoplatonic sources has shown the close continuity between Greek philosophy and Judeo-Christian speculation. A place of honor belongs to the Alexandrian Jew Philo, who (in accordance with Ex. 3:14) names God solely τὸ ὄν, excluding every determination (ἄποιος; cf. Leg. Alleg., I, 15; ed. Cohn-Wendland, I, Berlin 1896, p. 73, 27). Natural theology is called "wisdom" (σοφία), the knowledge of God "worship of God," the "way that leads to God" (H. A. Wolfson, Philo, I, Cambridge, [Mass.] 1948, p. 148). Philo, like the Stoics, attributes to God the care of the entire human race and of the whole universe (cf. De Prov., II, 44), without mentioning individuals: who nevertheless are not excluded from Providence, because he defends the truth of miracles that concern particular situations and persons. These uncertainties, however, disappear in the Christian writers: God is not only the transcendent spirit but is intelligence, life and love, not only in himself but also toward creatures (free creation) and in particular toward man (Incarnation). Natural theology in the Fathers is not cosmological or political speculation, as in classical antiquity, but is oriented toward man and considers the individual. Natural theology is therefore a reflection of the certainty of the teaching of the faith concerning the existence and nature of God, the creation and preservation of things, the divine dignity of man, the origin and final solution of the problem of evil...: it is because of this positive influence of Revelation on patristic philosophy that "the providence of individual persons stands as the starting point of the divine economy" (parable of the lost sheep). In particular, from Neoplatonism patristic natural theology took its caution in the use of the "divine names": thus St. Basil affirms a double class of divine names, the one with positive meaning, the names that "indicate the perfections proper to God," as when we call him good and just, creator and judge and the like; the others, instead, indicate him in relation to things that do not befit him, e.g., incorruptible, invisible, immortal... (Contra Eun., I, 10: PG 29, 536). A distinguished essay in natural theology is the Oratio theologica II of St. Gregory of Nazianzus (περὶ θεολογίας: PG 36, 25 ff.), which develops the following points: 1) (§§ 1-12): the absolute incomprehensibility of the divine nature in itself. However, it is possible to demonstrate by reason the existence of God as creator and preserver of all things, perfectly "incorporeal" (ἀσώματος): yet in saying that God is "incorporeal" we do not show that we know him as he is, but as he is not, and so too for the other attributes taken from creatures. 2) (§§ 13-16): the surest way of knowing God is that of Sacred Scripture, which calls him "spirit and fire, light and love and wisdom and justice and intelligence and Word..." in contrast to unworthy polytheism. 3) (§§ 17-21): the surest way is to ascend (with the guidance of Scripture) from our mind, which is "something formless and divine" (τὸ θεοειδὲς τοῦτο καὶ θεῖον), to God as from "the image to its archetype": thus did Enoch, Elijah, St. Paul. 4) (§§ 22-31): the spectacle of the order and harmony displayed in the world and especially in the kingdom of living things attests the existence of the Creator.
One cannot, however, speak in the Fathers of a natural theology standing on its own, because that presupposes a classification of knowledge, which will come only toward the end of the patristic era (with St. John Damascene) thanks to the assimilation of Aristotelian logic, so much as of an extension of theological reflections through the assumption of precise concepts from classical philosophy (Platonic, Stoic, etc.). The first explicit controversies over the autonomy of metaphysical natural theology, with respect to theology properly so called, are to be seen in the Muslim world between two currents of philosophical rationalism (Jalofah), which culminates in Averroes, and of theology (halām), the mystical fideism of Avicenna and especially of al-Ghazālī (cf. L. Gardet - M. M. Anawati, Introd. à la théol. musulmane, Paris 1948, especially pp. 133 ff., 316 ff.). The Arab polemic would feed the formation of natural theology in the Middle Ages, above all from the 13th century onward, when the translations of Averroes and Avicenna entered the West, to whom must be added two Jews, Avicebron and Moses Maimonides, proponents of agnosticism and theological occasionalism criticized by St. Thomas.
Latin Scholasticism, in its orthodox orientation, remains faithful to the patristic magisterium, especially that of St. Augustine, of Ps. Dionysius, of St. Gregory the Great, of the Damascene, who most directly inspire medieval natural theology. Progress concerns at most the method, which is taken from Aristotle with the contribution of the Arabs (Avicenna, Averroes and Moses Maimonides). It differs according to the orientation of the various schools: Augustinianism has recourse by preference to the doctrine of illumination, attempting with St. Anselm (v.) the a priori argument, and therefore a certain direct process; faithful to Aristotelianism, St. Thomas instead develops the a posteriori proofs and the method of analogy (v.); nominalism (v.) distrusts both a priori and a posteriori proofs and entrusts the knowledge of God solely to faith, anticipating Protestant fideism.
A separate mention is deserved by the Lullist Raymond of Sabunde (d. c. 1432; [v.]), author of the Theologia naturalis seu verius thesaurus divinarum considerationum ex naturae fontibus haustarum, tum theologis tum philosophis atque universis scientiarum artiumque studiosis plurimum profuturus (Venice 1581), whose prologue was placed on the Index in 1595 and removed from it by Leo XIII in 1900. The reason for the condemnation seems to have been not so much the defense of the almost exclusive authority attributed to Sacred Scripture in the knowledge of the faith, as the fact that the "book of nature" is presented in it as a source not only of the knowledge of God's natural attributes but also with regard to "salvation, perfection and the progress of eternal life." For example, in ch. 46 (developed in chs. 47-55) creation ad extra... "manifestat et arguit aliam productionem summam, occultam et aeternam in Deo, quae est de sua natura et suo proprio esse. In qua producitur Deus de Deo et per quam ostenditur summa Trinitas in Deo" (ed. cit., p. 33 b). In chs. 63-64 the Trinity is demonstrated with the ontological argument (pp. 52-54; cf. ch. 264, p. 286 b, the same for the mystery of the Incarnation). The work was praised by Hegel for its speculative vigor (cf. Gesch. der Philos., in Werke, XV, Berlin 1844, p. 175) and inspired the Romantic theologian Martin Deutinger to attempt a synthesis between Christian thought and the modern principle of self-consciousness (cf. I. Fellerer, Das Verhältnis von Philos. u. Theol. nach M. D., Bonn 1940, p. 57 ff. A disciple of Deutinger, Sighart, edited a new ed. of Raymond's Theol. nat. [Freising 1852]), which in the 17th century had the honor of being translated and defended by Montaigne (Essais, II, ch. 12; ed. Faguet, II, Paris n.d., p. 47 ff.).
Early Protestantism, while diminishing the powers of reason, does not entirely reject natural theology, and this by virtue of Rom. 1:20. According to the Formula Concordiae, Luther "accurate monuit longe aliam Dei cognitionem ex evangelio quam ex lege hauriri, quia etiam gentes ex lege naturae aliquam Dei cognitionem habuere, nec tamen eum recte vel agnoverunt vel coluerunt" (J. T. Müller, Die symbolische Bücher der evangelisch-lutherischen Kirche, Gütersloh 1928, p. 638 b). Starting from Melanchthon himself, who admits an ethics and a natural theology, the question is settled, as the theologian Huetter declares in the 17th century: "In Deum ipsum non ingratos modo, sed et contumellosos esse, qui vel notitias naturales negare, vel praestantissimum eorum effectum, philosophiam nimirum, opus carnis, sive peccatum nominare hodie non erubescunt" (in H. E. Weber, Reformation, Orthodoxie und Rationalismus, ibid. 1951, p. 17). The same may be said of the "little flame of free will" (ein kleines Fuencklein der freien Willens) that has remained in man to tend toward God in some way even after the fall, as the Pietist Jo. Arndt attests (cf. Das wahre Christentum, I, ch. 41, § 26, Leipzig 1764, p. 218 a). Ambiguous is the position of Calvin, according to whom fallen man can still distinguish between good and evil, but cannot find the way to ascend to God: indeed, although he admits that God has inserted a natural knowledge of himself into human minds — and this explains why there is no people without a religion — nevertheless this knowledge is not sufficient to ascend to God if it is not guided by the magisterium of Scripture, because the human mind is corrupted (cf. Institutio christianae religionis, I, 3 and 6; ed. Geneva 1569, p. 3 ff.). Bacon's definition, on the other hand, remains traditional: «Theologia naturalis philosophia etiam divina recte appellatur. Difinitur autem haec ut sit talis scientia, seu potius scientiae scintilla, qualis de Deo haberi potest per lumen naturae et contemplationem rerum creaturum» (De augmentis scient., II, 2; ed. Spedding-Ellis, I, London 1879, p. 544). Natural theology replaces revealed theology in the deism (v.) of Herbert of Cherbury (1581-1648) by means of the five truths set forth in the De veritate of 1624: 1) there exists a supreme deity; 2) he must be worshiped by man; 3) virtue has always constituted the chief part of the worship of God; 4) vices and crimes must be expiated; 5) after this life reward or punishment awaits (cf. M. M. Rossi, Alle fonti del deismo e del materialismo moderno, Florence 1942, p. 6): a conception that returns in John Toland (v.), who denies the existence of any mystery transcending the human mind (cf. Clidophorus, in Works, London 1720, p. 63 ff.).
The ambiguity of Calvin's position regarding natural theology returns today respectively in the interpretation of E. Brunner and of K. Barth: while the former made ample concessions to the Thomist position of the natural knowledge of God, the latter denied the possibility of a "point of contact" (Anknüpfungspunkt) and characterized the Thomist doctrine of analogy as an "invention of the Antichrist" (Dogmatik, I, 5th ed., Zurich 1947, p. VIII).
Neo-Scholasticism took the term natural theology (theologia naturalis) from Wolff, who defined it as "scientia eorum quae per Deum possiblia intelliguntur" and assigned to it as its object the existence, the attributes and the effects of God (Philosophia rationalis sive logica methodo scientifica pertractata, §§ 57 and 96, Verona 1779, pp. 15 and 23 ff.). But Christian philosophy, while taking the term natural theology from the Enlightenment, rejects its method and its rationalist spirit, in conformity with the teaching of the Church.
The problem of the nature and method of natural theology depends ultimately on the very notion of philosophy and on the possibility of human reason to attain the absolute; and furthermore on the concept of divine revelation that allows one to clarify the relationship between reason and faith (v.).