Published online by Cambridge University Press: 05 November 2010
The philosophy in Christianity is both inert and active. The late Greek metaphysics around which Christian doctrine first developed is Christianity's inert philosophical skeleton. Even if the dehellenizers could succeed in their efforts to remove it, Christianity itself would be unrecognizable without it. But the philosophy that is in Christianity actively, the enterprise of philosophical theology, is in it insecurely and only intermittently because it seems vulnerable to important religious and philosophical objections. As I see it, philosophical theology can be and actually has been successfully defended against those objections, and it is, I believe, incomparably the most interesting and important philosophy in Christianity—in fact, the only philosophy of more than historical interest there really is in Christianity.
1 See Scott MacDonald's article ‘Theologia naturalis/Theodicy’ in the forthcoming Handbook of Ontology and Metaphysics, Burkhardt and Smith (eds) (Munich: Philosophia Verlag). I am grateful to Professor MacDonald for letting me see an advance copy of his article.
2 See MacDonald, op. cit. As MacDonald describes it, broad natural theology might countenance accepting a doctrinal proposition expressed in Scripture as justifiably believed although not, of course, as divinely revealed. Philosophical theology, by contrast, may be unconcerned with the proposition's initial justification, treating it as an assumption.
3 See, e.g., Plantinga, ‘Reason and Belief in God’, in Plantinga, and Wolterstorff, (eds), Faith and Rationality: Reason and Belief in God (Notre Dame, Ind.: University of Notre Dame Press, 1983, 16–93)Google Scholar, 40: ‘Thomas Aquinas, of course, is the natural theologian par excellence’.
4 Wolterstorff indicates this clearly in his Introduction to Faith and Rationality (see n. 3 above), where in explaining the neologism ‘“Calvinist epistemology” or “Reformed epistemology”’ he says, ‘Characteristic of the Continental Calvinist tradition has been a revulsion against arguments in favour of theism or Christianity. Of course, at its beginnings this tradition was not appraising the giving of such arguments in the context of the Enlightenment insistence on the importance of Reason. It was instead appraising it in the context of the long medieval tradition of natural theology’ (7–8).
5 Reason Within the Bounds of Religion (Grand Rapids, Mich.: William B. Eerdmanns, 1976), 26, 29.Google Scholar
6 Op.cit.,48, 62.
7 Plantinga sometimes restricts natural theology along these lines—e.g. ‘Suppose we think of natural theology as the attempt to prove or demonstrate the existence of God’ (op. cit., 63), but as a target for criticism on the basis of Reformed epistemology it is typically characterized more broadly. See, e.g., this passage from Wolterstoff, in which he is describing ‘the practice of natural theology among the medievals’: ‘We may take Anselm and Aquinas as typical—Anselm's goal in constructing the ontological argument, as [in] the remainder of the Proslogion, was to bring it about that what already he believed he now would know. In his view an essential component in this process of transmuting belief (faith) into knowledge (understanding) was constructing proofs. Aquinas was no different on these matters…. the goal of natural theology for Aquinas was exactly the same as for Anselm: to transmute what already one believed into something known. Demonstration was seen as indispensable to this transmutation project' (‘Can Belief in God Be Rational?’, 135–186 in Plantinga and Wolterstorff, op. cit., 140–141; emphasis added). The goal and the method picked out here do belong to natural theology strictly construed, which is perhaps more prominent in Anselm than in Aquinas, but the clear suggestion of this passage is that that goal and method belong to Anselm's and Aquinas's applications of reason to revelation quite generally. As we will see, that suggestion is misleading, at least in the case of Aquinas and other thirteenth-century philosophical theologians. (I criticize Plantinga's anti-evidentialism on non-historical grounds in ‘Evidence Against Anti-Evidentialism’, forthcoming in a volume edited by Kelly Clark).
8 I discuss Augustine in this connection in my article ‘Faith Seeks, Understanding Finds: Augustine's Charter for Christian Philosophy’ in Flint, Thomas (ed.), Christian Philosophy (Notre Dame, Ind.: University of Notre Dame Press, 2000).Google Scholar
9 The treatment of Tertullian in the following paragraphs is adapted from my article cited in n. 8 above.
10 De praescriptione haereticorum, vii, 2–3 (ed. R. F. Refoule, Corpus Christianorum Series Latina [CC], Vol. I, 92.4–7).
11 De praescriptione haereticorum, vii, 12 (ed. cit., 193.37–39).
12 Epistula CXX,i,3. See my article ‘Faith Seeks…’(n. 8 above) for further discussion.
13 I defend this interpretation in ‘Faith Seeks …’.
14 XL Homilia in evangelia, II, hom. 26, n. 1: ‘Sed sciendum nobis est quod divina operatio si ratione comprehenditur, non est admirabilis; nec fides habet meritum, cui humana ratio praebet experimentum’ (PL 76.1197C).
15 Ep. ‘Ab Aegyptiis argentea’ ad theologos Paris., 7 Iul. 1228 (‘Denzinger’, ed. xxxvi (1976), 824).
16 III Sent., d. 24, a. 2, q. 2c, and ad 2 (edn. III, 521). See also Prooemium, q. 2, obj. 6, and ad 6 (edn. I, 10–11); and Quaestiones disputatae de mysterio trinitatis q. 1, a. 2, s.c. 3, and ad 3 (edn. V, 53, 57).
17 For Bonaventure's assessment of the relationship between faith and the sort of knowledge it is possible to have of such theological propositions as ‘God exists’ and ‘God is one’, see III Sent., d. 24, a. 2, q. 3 (edn. III, 521–524), where his conclusion is that while faith is not compatible with the knowledge characterized by free and open comprehension that is an aspect of the beatific vision (which of course involves comprehension of all truths about God and not just those theoretically accessible to natural theology), it is not only compatible with but dominant over the highest degree of knowledge available in this life, the sort obtained by the use of demonstrative reason, the sort especially associated with natural theology. On this last point Bonaventure clearly differs from Augustine (see ‘Faith Seeks …’, cited in n. 8 above) and Aquinas (see Summa theologiae [ST] IIaIIae q. 1, a. 5, and Ia q. 2, a. 2, ad 1, where he distinguishes as ‘preambles’ to faith the doctrinal propositions he takes to have been proved).
18 Cf. Prooemium, q. 2c.
19 Sententiae, IV, d. 11, c. 2, n. 2 (Editio Tertia; Grottaferrata (Romae): Editiones Collegii S. Bonaventurae ad Claras Aquas, 1981). Peter attributes the passage to Augustine ‘in libro Sententiarum Prosperi’, but the editors correct the reference to Lanfranc [1010–89], De corpore et sanguine Christi, c. 10 (PL 150.421D).
20 IV Sent., d. 11, p. 1, a. un., q. 6, dub. 1 (edn. IV, 252). For the allusion to Augustine here, see n. 19 above. Aquinas takes much the same tack with this objection. IV Sent., d. 11, q. 3, a. 4, expositio textus: ‘[A mystery] “cannot be investigated in a way conducive to salvation”—i.e. if someone is investigating in order to try to comprehend it. For it is presumptuous and dangerous when a person does not want to believe more than can be seen by reason. Investigating for purposes of defending the faith is useful, however.’ But Richard of Middleton, writing a few years later, shows more concern with the structure of philosophical theology than with its application in apologetics. IV Sent., d. 11, q. 6, circa litteram: ‘As for the passage “it cannot be investigated in a way conducive to salvation”, it is to be understood as alluding to a prying (curiosa) investigation that goes beyond appropriate limits, or to an investigation that is not founded on faith’. On the medieval attitude toward illegitimate curiositas see Aertsen, Jan A., Nature and Creature: Thomas Aquinas's Way of Thought (Leiden: E. J. Brill, 1988), 33–40.Google Scholar
21 De carne Christi, v, 4 (ed. E. Kroymann, CC Vol. II; 881.27–29).
22 Concilium Vaticanum I: sessio III: Constitutio de fide catholica, Cap. 4. De fide et ratione (‘Denzinger’, ed. cit., 3015, 3041).
23 I treat Aquinas's approach to trinity much more fully and somewhat differently in my article ‘Trinity and Transcendentals’, forthcoming in Feenstra, Ronald J. and Plantinga, Cornelius Jr (eds), Trinity, Incarnation, and Atonement (Notre Dame, Ind.: University of Notre Dame Press, 2000).Google Scholar
24 ST la q. 32, a. lc.
25 ST la q. 32, a. lc.
26 ST la q. 32, a. 1, ad 2. For some detailed applications of philosophical theology to trinity besides ST Ia qq. 27–43 see, e.g., Summa contra gentiles, IV, 2–26; Quaestiones disputatae de potentia, qq. 8–10; Compendium theologiae, Chs. 36–67.
27 See also the Prooemium of Aquinas's Commentary on Boethius's De trinitate: ‘Now the method of treating of the Trinity is two-fold, as Augustine says in De trinitate I (ii, 3–4)—viz. on the basis of authorities and on the basis of reasonings. Augustine combined these two methods, as he himself says [ibid.]. But some of the holy Fathers, Ambrose and Hilary, for example, used only the one based on authorities. Boethius, on the other hand, decided to pursue the other method, the one based on reasonings, presupposing what other men had tracked down on the basis of authorities.’ Notice that Aquinas's full description of Boethius's approach to trinity shows it to be, like Augustine's and Aquinas's, the approach of philosophical theology. Armand Maurer's translation of this passage is on pp. 5–6 of his Thomas Aquinas: Faith, Reason, and Theology (Toronto: Pontifical Institute of Mediaeval Studies, 1987)Google Scholar. I am grateful to Scott MacDonald for calling my attention to the passage.
28 ST Ia q. 32, a. 1, ad 3.
29 Clement of Alexandria seems to have gone much further—too far—in this direction. ‘His main concern is to meet the pagan critic who scorns faith as an unreasoning opinion formed without proper consideration … Clement replies, first, that all argument has to take something for granted, and faith in religious knowledge is analogous to those initial postulates which make subsequent discussion possible’ (Chadwick, Henry, Early Christian Thought and the Classical Tradition: Studies in Justin, Clement, and Origen (Oxford: Clarendon Press, 1966), 52)Google Scholar. Chadwick cites Clement's Strōmateis, ii, 13, 4; vii, 95; viii, 6–7; and Ek tōn prophētikōn eklogai, 4, 2.
30 For a classic presentation of this attitude, see Augustine, Epistula CXX, ii, 12: ‘And if … the human, rational, intellectual soul, which was made in God's image, does not elude our thought and understanding, if by mind and understanding we can grasp its excellence, … it may not be absurd for us to try to raise our soul to understanding its creator as well, with his help. But if it fails in this and falls back on itself, let it be content with devout faith as long as it is wandering, absent from the Lord.’
31 Retractationes I, ix, 1.
32 De ordine II, ix, 26.
33 De vera religione, xxiv, 45.
34 De utilitate credendi, xiv, 31.
35 Augustine's remonstrations with Consentius provide an illustration of this attitude: ‘you say that you have laid down a principle for yourself that truth must be perceived on the basis of faith rather than on the basis of reason. … See, then, whether in accordance with those words of yours you should not follow only the authority of the saints in this matter [the doctrine of the Trinity] on which our faith is chiefly founded, rather than asking me to make it understandable to you by reason. For when I begin to lead you into the understanding of so great a mystery in any way at all (something I will be able to do only if God helps from within), all I will be doing in discussing it is giving you such reasons as I can’ (Epistula CXX i, 2).
36 Quaestiones disputatae de mysterio trinitatis (Quaracchi edn. V, 45–115) was written probably around 1256, near Bonaventure's departure from the University of Paris to take up his duties as General of the Franciscan Order. It has been translated by Hayes, Zachary, OFM, Saint Bonaventure's Disputed Questions on the Mystery of the Trinity: An Introduction and Translation (St Bonaventure, NY: The Franciscan Institute, 1979)Google Scholar. For historical data, the place of this treatise in Bonaventure's work, and a good deal of valuable background information, see Hayes's detailed Introduction.
37 Here are the Theses of the other articles. Q. 3, a. 1: ‘The divine being (esse) is supremely simple’; a. 2: ‘The Trinity of the Persons does not do away with supreme simplicity, nor does supreme simplicity exclude trinity’; q. 4, a. 1: ‘Because the divine being and capability (posse) is supremely simple it is infinite (in so far as “infinite” rules out a limit to the quantity of power [virtus])’; a. 2: ‘In God supreme infinity is compatible with the Trinity of the Persons’; q. 5, a. 1: ‘The divine being is eternal because it is simple, all at once, and infinite’; a. 2: ‘Necessarily, the Trinity of the Persons is compatible with eternality’; q. 6, a. 1: ‘The divine being is altogether immutable’; a. 2: ‘The Trinity of the Persons is compatible with supreme immutability’; q. 7, a. 1: ‘The divine being is necessary with the absolutely perfect necessity of immutability’; a. 2: ‘The necessary and supremely free divine being is compatible with the Trinity of the Persons’.
38 Q. 1, a. 2, occupies pp. 51–58 of Vol. V of the Quaracchi edition. My references to short, numbered units of the article will be clear without further detail. In other cases I will attach page and line numbers to the quoted passages.
39 Arguments A1–A8, those in support of characterizing trinity as a proposition one is obliged to believe, are all based primarily on authoritive pronouncements on requirements for salvation, each of which is said to imply believing trinity. Perhaps the clearest example is Al, which combines the trinitarian formula of baptism in Matthew 28:19 with Mark 16:16, ‘He that believeth and is baptized shall be saved; but he that believeth not shall be damned’.
40 It is worth noting that in A9, as occasionally elsewhere in q. 1, a. 2, the proposition explicitly at issue is not merely ‘God is three’, but ‘God is three and one’.
41 The only evidence of trinity's credibility offered in these arguments besides the claim that belief in trinity is a necessary condition for salvation is added in A3, which also points out ‘the danger in going wrong’ in an inquiry into trinity. That could look like an argument for remaining content with mere belief if it were not tied to a quotation from Augustine's De trinitate I, iii, 5: ‘When one inquires into the unity of the Trinity—of the Father, the Son, and the Holy Spirit—nowhere is it more dangerous to go wrong, more difficult to inquire, or more rewarding to discover something’.
42 Briefly, the extrinsic considerations cited are these. A9 and A10 point out that trinity is the fundamental proposition put forward for belief (a status that will become clear later); A11 and A12 claim that trinity is believed by the wise and by an innumerable multitude; A13 cites the authority of Scripture along with trans-authoritative considerations of its antiquity, miracles, and prophecies. A14, the most interesting of the lot, cites Augustine's threefold classification of credible things (De diversis quaestionibus LXXXIII, q. 48), in which historical propositions are described as merely credible but never understandable, and theological propositions are described as understandable if they are first believed. Bonaventure's line is that propositions of the latter sort, the eventually understandable ones, are ‘more credible’ than the former, and so trinity is even more credible than ‘Abraham begot Isaac’, which is ‘very credible indeed’.
43 Beyond such simple claims as ‘all reason dictates the contrary of the proposition that one is really three’ (N1), there is no attention in these arguments to the content of trinity except this in N2: ‘All created nature displays the contrary of the [trinitarian] proposition that what is one in a form that is not made many is made many in entities that have that form, since in connection with every created nature, when the entities that have the form are made many, the form is made many’ (contrarium huius quod est, unum in forma non multiplicata multiplicari in suppositis, praetendit omnis natura creata; in qualibet enim natura creata, supposito multiplicato, multiplicatur forma). And even in N2 the main thrust of the argument is extrinsic to trinity: ‘Everything whose contrary is displayed by created nature is incredible to reason’. Arguments N1–N4 deny that trinity is rationally suitable to be believed, N5–N7 deny that it is religiously suitable, and N8 denies that it is in any way suitable to be believed.
44 I have translated Bonaventure's active infinitive here as if it were passive in order to accommodate ‘worthy’.
45 Perhaps the noteworthy differences between the opening arguments and the Reply reflect the practice common among thirteenth-century masters of assigning the development of those arguments to one's students.
46 Bonaventure's use of ‘testitnonium’ here is an unmistakable allusion to I John 5:7, ‘Tres sunt, qui testitnonium dant in caelo, Pater, Verbum, et Spiritus sanctus, et hi tres unum sunt’, a passage he discusses later in his Reply (55b22–30). Although ‘testimony’ (as KJV has it) is clearly preferable to ‘evidence’ as a translation of ‘testitnonium’ in I John, the line Bonaventure develops in the remainder of his Reply seems to call for ‘evidence’; here.
47 Strictly speaking, the evidence presented in Bonaventure's Book of Nature constituted a basis for natural theology only before the Fall. The evidence is still there, but post-Fall human beings can make only diminished use of it, and only after they have found out otherwise what to look for.
48 Bonaventure pretty clearly derives the designation from John 1:4, ‘In him was life; and the life was the light of men’, which he cites in this connection (55b39–40). Still, in his own terminology it is light, not life, with which the evidence in this Book is directly associated. For a thorough presentation of thirteenth-century considerations of the concept of the Book of Life and its association with the second Person of the Trinity, see Aquinas's disputed question De libro vitae (Quaestiones disputatae de veritate, q. 7).
49 Bonaventure also characterizes the cognitive aspect of the beatific vision as the Book of Life (55b34–37), but what this Book provides after this life is not really evidence, as Bonaventure suggests by the adverbs he uses in his characterization of the celestial version: per se, in se, explicite, expresse. I confine my attention to the Book of Life in this life.
50 ‘… ex quorum luminum concursu habitus fidei tanquam argumentum elicitur ad credendum, Deum esse trinum, et consequenter omne verum, quod pertinet ad christianae religionis cultum.’ The crucial phrase ‘the habit of faith is elicited [in a person] as evidence for believing’ strikes me as particularly difficult. (I feel warranted in translating ‘argumentum’ as ‘evidence’ largely because the Vulgate has ‘argumentum’ where KJV has ‘evidence’ in Hebrews 11:1—‘Faith is … the evidence of things not seen’.) Scott MacDonald has called my attention to a remarkable passage in Aquinas that can be read almost as if written in an attempt to explain this difficult passage in Bonaventure—i.e. In librum Boethii De trinitate q. 3, a. 1, ad 4.)
51 I am grateful to Scott MacDonald and to Eleonore Stump, each of whom prepared detailed, helpful comments on an earlier draft of this paper.