Rethinking the Medieval Legacy for Contemporary Theology

Anselm K. Min, Anselm K. Min

• Editore: University of Notre Dame Press
• Anno: 2014
• ISBN:
  9780268158774
• Argomento: Theologie & Religion
• Categoria: Christliche Theologie

In Rethinking the Medieval Legacy for Contemporary Theology, six distinguished theologians bridge medieval and contemporary theologies by developing the theological significance of medieval insights in response to contemporary issues. Their nuanced readings of medieval texts, extended to major theological issues of our time, provide examples of the retrieval of the medieval tradition, an essential part of any contemporary theological reconstruction.

Barbara Newman extends the theology of perichoresis or mutual indwelling to illuminate the relationship between donor and recipient in the case of organ transplants; Marilyn McCord Adams applies insights about divine friendship to the perennial issue of horrendous evil; and Kevin Madigan brings principles of medieval exegesis to bear on the contemporary historical critical approach to biblical interpretation. Ingolf U. Dalferth applies insights from the doctrine of divine omnipotence and creation ex nihilo to deconstruct Heidegger's limitation of the possibilities of authentic existence to historical facticity. Pim Valkenberg explores the possibilities of a theological encounter between Christianity and Islam in the works of Aquinas and Nicholas of Cusa; and Anselm K. Min applies the analogical insights of Aquinas on the nature and limits of human knowledge of God to a critique of contemporary theologies that claim to know either too little or too much about God.

Chapter Four

POSSIBILE ABSOLUTUM

The Theological Discovery of the Ontological Priority of the Possible

INGOLF U. DALFERTH

FROM THE SCIENCE OF BEING TO THE SCIENCE OF THE POSSIBLE

“There is a science,” says Aristotle in Metaphysics IV 1003 a, 21, “which investigates being as being” (τό ὄν ᾗ ὂν). In contrast to special sciences such as physics or mathematics, which investigate the attributes of a part of being, first philosophy or metaphysics, as it came to be called in the Aristotelian tradition, is the science that studies what is insofar as it is (περὶ τοῦ ὄντος ᾗ ὂν).¹

Some two thousand years later and in sharp contrast to Aristotle, Christian Wolff defines philosophy in his Discursus praeliminaris de philosophia in genere (1731) as the science of the possible insofar as it can be: “Philosophia est scientia possibilium, quatenus esse possunt.”²

And in the twentieth century we hear from philosophers like Heidegger that “higher than actuality stands possibility,”³ and theologians like Jüngel propose an ontological “priority of possibility over actuality”⁴ because “God is to be conceived as the one who makes the possible to be possible and the impossible to be impossible. As the one who does this … God distinguishes himself from the world. And in that he distinguishes himself from the world, God lets the world be actual.”⁵

This change from the priority of the actual over the possible to the priority of the possible over the actual is significant. It is one thing to investigate what is insofar as it is, quite another to study what is possible insofar as it is possible. What is the significance of this change, and how did it come about? My answer is that it manifests an ontological revolution that took place between the twelfth and the fourteenth century and whose impact on our thinking and doing to this very day cannot be overestimated, and that this revolution would have been unthinkable without theology.⁶

POSSIBILITY IN ARISTOTLE

Since the time of Aristotle it has been clear that one cannot study being without reference to modality. Nothing is what it is without being it in a certain mode. This is true of beings (metaphysical and physical modalities) as much as it is of propositions (alethic modalities). But which modes of being have to be taken into account in the study of being as being? Merely possibility and necessity and their contraries and contradictories (impossibility, non-necessity, contingency), or also actuality (reality), truth and falsity (vera/falsa), bona/mala, scita/ignota, concepta, credita, opinata, dubitata, as William of Ockham proposed in the spirit of Aristotelianism in the fourteenth century?⁷ And even if we confine ourselves to the alethic modalities necessary, contingent, impossible, possible, how are they to be understood? Modal terms notoriously have many senses (pollachos legomena). Aristotle’s various and inconsistent attempts to systematize the (metaphysical or alethic) modalities have opened up different avenues of reflection.

In the Analytica priora I.2, 25a1, he distinguishes three modal terms which can be predicated of being: necessary, possible (= that which is not impossible), and actual or contingent (= that which is not necessary and not impossible); and this threefold division can still be found in Kant’s theory of modality which distinguishes between possibility, existence, and necessity as the three basic ways of a subject’s relation to the content of a judgment.

In De interpretatione 12, 21b26 ff., on the other hand, Aristotle accepts only necessity and possibility as modes, whereas actuality is that which is modified by the modal terms; and in this he is followed by most contemporary modal theories, which accept only two modalities, necessity and possibility, even though there is no difference in grammatical structure between “p is real” (“It is the case that p”) and “p is necessary” (“It is necessarily the case that p”). But the difference shows in negation. Whereas “It is not the case that p” is equivalent to “It is the case that not p,” “It is not necessary that p” is not equivalent to “It is necessary that not p.”

In De interpretatione 12–13 and the Analytica priora (I.3, 13) Aristotle distinguishes between necessity and possibility but defines possibility as contingency (in the broad sense), that is, as that which is not necessary and not impossible. But he also uses a more general notion of possibility defined as that which is not impossible. The latter notion merely excludes impossibility but includes necessity, that is, that which is impossible not to be. The former notion (contingency), on the other hand, does not include everything that is not impossible but excludes the necessary. Thus the first notion of possibility includes necessity whereas the second doesn’t.

However, the notion of possibility is even more ambiguous than Aristotle’s account as represented so far suggests. Subsequent discussions through the centuries up to Leibniz have brought out that there are at least two further notions of possibility besides the two outlined:

1. The possibile in the broadest sense (Mp), which is the contradictory of the impossibile (–Mp)

2. The possibile in the sense of Aristotle’s endechomenon (–Np & – (–Mp)), which is neither necessary nor impossible

3. The possibile in the sense of the contingens (p & M–p) in Leibniz’s sense, which is neither necessary nor impossible but exists even though it could not have existed

4. The possibile in the sense of the mere possibile (–p & Mp) or esse in potentia, which is neither necessary nor impossible and does not exist

The last two versions of possibility can only be distinguished by recourse to the difference between being (esse) and nonbeing (non-esse), and this is why actual or actuality is sometimes counted as a third modality of being. Aristotle’s account in De interpretatione 12 and Analytica priora I.2, 25A 1–3, gave rise to couching this difference in terms of modi recti et obliqui, that is, absolute and relational modalities. Relational modalities such as possible, necessary, impossible, nonnecessary always qualify a being or becoming, that is, an einai (esse) or a gignesthai (fieri); they cannot stand on their own but are relative to the absolute modalities (esse, fieri, non-esse; or: p, –p) which they modify. However, strictly speaking, absolute modalities are no modalities at all but that which is modified by modal terms. Modal terms are modifiers and cannot be used meaningfully in an absolute way. Modes are always modes of something: Only what is actual can be possible, and only what is can be necessary. Without actuality there is no possibility or necessity.

This is also true of the mere possibile which understands possibility (possibilitas) as a potency (potentia);⁸ for every potency is the potency of something or someone. Nothing can be mere possibile unless it is related to an actual reality. But then what is possible differs from what is actual only by being not yet or no more actual: Possibility is possible actuality, actuality takes place in time, and hence all possibility is the possibility of something past, present, or future. Thus no genuine possibility can remain forever unrealized, as the so-called Principle of Plenitude holds.⁹ Aristotelian possibility in all its various senses does not involve reference to simultaneous alternatives but is understood in a statistical or temporal frequency way: Whatever is possible, was, is, or will be actual.¹⁰

A DIALECTICIS LIBERA NOS, DOMINE

It is not surprising that this account of modality was hard to accept for Christian thinkers. Al-Farabi (872–951) reports that Christian bishops allowed the study of Aristotle’s Organon only to the end of the theory of categorical syllogism; the theory of modal syllogism was not permitted because this was considered to be detrimental to and dangerous for the Christian faith. This critical stance toward Aristotle’s theory of modality continued well into the eleventh century.¹¹ His view that actuality has priority over possibility was taken to be incompatible with divine omnipotence and to create aporias in the understanding of divine providence, foreknowledge, and freedom. In his De divina omnipotentia, Peter Damian (1007–72) narrates that he discussed with young monks in Montecassino the quaestio frivola: “Numquid potest Deus hoc agere ut, postquam semel aliquid factum est, factum non fuerit?”¹² The monks cited Hieronymus who had warned a young woman, “Audenter loquor, cum omnia possit Deus: suscitare virginem non potest post ruinam.”¹³ For if one follows Aristotle that “quidquid nunc est, quamdiu est, procul dubio esse necesse est,”¹⁴ then what is now the case is necessary and hence cannot be changed, not even by God.

However, the argument confuses the necessitas consequentiae (N(p–>p)) with the necessitas consequentis (p=>Np). The inference p=>Np is a modal shift fallacy and to be rejected for logical reasons. But such arguments are also unacceptable for theological reasons, as Peter points out, because they unduly constrain God’s omnipotence and, as he puts it, “eum penitus impotentem reddant.”¹⁵ If modal arguments interfere with divine omnipotence, so much the worse for them.

DEO NIHIL EST IMPOSSIBILE

Here is the linchpin of the entire debate. Since the days of Homer it was accepted that θεοί δέ τε πάντα δύνανται (Odyssey X, 306). “Nihil est,” as Cicero puts it, “quod deus efficere non posit.”¹⁶ Jesus was taken to say the same when he replied to the Pharisees that what is impossible with men is possible with God (Luke 18:27). But if everything is possible for God, what exactly is the reference range or distribution of this “everything”: Does it mean all that is impossible with men? Or all that is possible? Or all that is either possible or impossible? Tertullian saw the problem and stated more precisely: “Deo nihil est impossibile, nisi quod non vult.”¹⁷ It is God’s will that determines what for God is possible or impossible, and God’s will is absolutely free and not constrained by any necessity or impossibility. Anselm put it as usual in a precise way in Cur Deus homo? II,17: “Omnis quippe necessitas et impossibilitas ejus subjacet voluntati: illius autem voluntas nulli subditur necessitati aut impossibilitati.”

However, this still leaves open the question whether what is possible is so because God wills it or whether God wills it because it is possible? Thomas Aquinas answered, “Deus dicitur omnipotens, quia potest omnia possibilia absolute, quod est alter modus dicendi possible” (ST I, q. 25, a. 3 resp.).

POSSIBILITAS AND POTENTIA

This argument deserves to be examined in more detail. It belongs in the context of the debate about the creation of the world that led to a new theological interest in the modalities in the twelfth century. Contrary to the antidialectical attitude of the eleventh century (A dialecticis libera nos, Domine), John of Salisbury (1120–80) points out in his Metalogicon (IV.4) that the ratio modorum (knowledge of the modalities) is of great importance (pernecessarium) for the study of Holy Scripture. And a similar interest can be seen in Abelard, who introduced the distinction between de re and de dicto in the logic of modalities.

However, Aristotle’s Metaphysics and Physics became available in the West only in the thirteenth century, and hence also his metaphysical theory of modality outlined in Metaphysics IX (theta) that distinguishes between energeia (actualitas) and dynamei on (potentia).¹⁸ Possibility is the potentia to be actual or to do something actually. Thus every change in the actual involves a change from the possible to the actual, and what cannot become actual, cannot be possible. Already Avicenna (980–1037) distinguished between possibilitas and potentia, between the possibility of something or someone (“It is possible to ϕ”) and the potency or competence of something or someone to be or to do something (“It is possible for a to ϕ”). In either case the possibility or potency was understood to be relative to some actuality: Possibility is always the possibility of something actual, and the same is true of potency.

POSSIBILE ABSOLUTUM

In Metaphysics IX (theta) Aristotle had introduced these modal distinctions in order to be able to describe and analyze the manifold changes in the kosmos. This helped Christian thinkers to understand becoming in the world, but it was of no help in understanding the becoming of the world, that is, the creatio ex nihilo. In Aristotelian terms this required postulating an actual potency that actualizes the possibility of the world. But this possibility of the world could no longer be understood as the possibility of the actual world but had to be presupposed as possibility: It was no longer a relative possibility but an absolute possibility, a possibile absolutum.

This led to a completely new paradigm of modal thinking. The...