Fate and Contingency: Ammonius and Aquinas on Divine Foreknowledge in Aristotle’s De Interpretatione 9

Abstract

This article compares Ammonius’ and Aquinas’ answers to the conflict between divine determinate knowledge of the world and the contingency of future events. The first section analyzes the Proclean distinction of the three degrees of knowledge that Ammonius attributes to Iamblichus and accompanies this with a commentary on Aristotle’s De interpretatione 9. First, Ammonius stresses divine transcendence, according to which not even our ‘now’ is similar to the divine. Second, Ammonius applies the “Iamblichus’ principle” to the knowledge of future contingents. This is in order to reconcile both divine foreknowledge and natural contingency. From this, it is possible to conclude that the gods have a certain knowledge that is ontologically superior to the object known. In a second section, Aquinas’ solution will be presented. In Aquinas’ commentary, although not referring to the same distinction, he identifies a similar phenomenon in which the same principle applies: certain knowledge of a contingent present event does not alter its contingent nature. Aquinas applies this principle to God, who knows not only the present but also the past and future contingents, with one unique, transcendent vision. His emphasis on the transcendence of divine knowledge and will also connects him to Ammonius.

1. Introduction

Is there Fate in human affairs? Does God or the gods predestinate human lives? Does the universe work in a completely determined way? Or if that is not the case, if everything is not predetermined, does God know what will happen? Is there a divine foreknowledge of future events? When we read Aristotle’s treatises, these kinds of questions seem to be left aside—although it is a very interesting exercise to infer from physics and metaphysics what could be said about these subjects. Despite not addressing the reality of Fate, Aristotle offers a theology in Metaphysics XII, which is also enriched by several references to the divine throughout his entire work. According to this theology, it is reasonable to hold that God knows the world.1 Some Aristotelian scholars maintain that God only knows himself.2 However, a reason to distance oneself from these scholars’ position and sustain God’s knowledge of the world lies in Aristotle’s affirmation that God governs the world. This governance is not only by causing the world’s order but also by leading it as a general governs its army. This kind of government, proper to a military leader, requires knowledge of what is being led.3

This paper will show, in the context of a logical discussion regarding the truth or falsity of future singular propositions in which Aristotle defends the existence of the contingent, how two commentators, Ammonius and Aquinas, undertake this intellectual task: developing a divine gnoseology in order to solve the dilemma of defending either the contingency of events or divine foreknowledge. On the one hand, how can God’s knowledge be perfect if he does not know the future contingents? But on the other hand, how could there be real contingency when God already knows what will happen?

The problem of divine foreknowledge does not appear explicitly in Aristotle’s De interpretatione 9. However, his commentators seem to understand that this is what is at stake in the problem of the truth or falsity of the future contingent propositions. To resolve the dilemma, they will consider not only Aristotle’s words but also appeal to other sources, some earlier than and known to Aristotle, such as Homer, Parmenides, and Plato, and others posterior to him, as Proclus and Iamblichus.

Therefore, it is of interest to compare how two commentators of different backgrounds, one Greek and Pagan, Ammonius Hermiae, the other Latin and Christian, St. Thomas Aquinas, turn to a divine gnoseology to save the contingency of the natural world without taking perfection away from divine knowledge. Both commentaries are also connected by the fact that Aquinas seems to have in mind not only Boethius’ commentary but also Ammonius’ (Torrijos Castrillejo 2020, p. 152). As will be seen in the analysis of their commentaries, both Ammonius and Aquinas need to place the divine reality beyond the limits of natural beings.4 Ammonius will propose that not only are the gods in an eternal ‘now’, but also that their ‘now’ is different from our ‘now’, stressing in this way the transcendence of the divine substances. Aquinas’ solution does not reject Ammonius’ position. While Aquinas recurs to a spatial metaphor, his intention will be the same: to show that God’s transcendence of causation is a limit that shapes our understanding while, at the same time, making possible the harmony between his foreknowledge and the contingency of future events.

2. Aristotle and the Knowledge of the Future Contingent

In De interpretatione 9, after stating whether propositions about past or present facts are necessarily true or false, whether they be universal or singular (18^a28–33), Aristotle analyzes the situation of future singular propositions (18^a33–18^b5), in which the problem of saving contingency arises.

To discuss the situation of future singular propositions, Aristotle follows the following steps. First, he addresses the question of whether everything happens by necessity or by chance (18^b5–19^a6). Second, he admits the evidence of human deliberation and action (19^a7–11).5 Third, he distinguishes between necessary occurrences or omissions and the contingent. The contingent is that which would either happen most of the time (ἐπὶ τὸ πολὺ θάτερον) or that which has a similar probability of occurrence or not (τὰ μὲν ὁπότερ’ ἔτυχε) (19^a11–22). Fourth, he also needs to distinguish between the actual and potential being of the facts expressed by the future contingent propositions (19^a23–29). Fifth, he affirms what we could call ‘the necessity of the contingence’.6 By this, Aristotle means that it is necessary that some future event occur or not occur, such as a naval battle (19^a29–32). Sixth, he acknowledges the relation of precedence of reality before the propositions whose truth depends on the actual realization of facts (19^a32–39).7 Lastly, Aristotle complements the affirmation of the ‘necessity of the contingent’ by clarifying that neither of the members of the disjunction is necessary (19^a39–^b4), leaving the only possible inference that what is necessary is only the possibility of one of the options happening or not. As it shows, Aristotle does not address the problem of divine foreknowledge when he discusses the nature of future contingent propositions in this brief chapter (less than three columns in Bekker’s edition).

If we ask ourselves why from these lines a discussion on divine foreknowledge will arise among their commentators, we should consider that Aristotle provides throughout his works the elements that are needed to face this problem: his Physics gives us a profound analysis of contingent and necessary natural events (cfr. Oliva 2024, p. 7); his Metaphysics settles the base to understand divine nature and its knowledge; his Organon, to which De interpretatione belongs, produces the distinctions needed to analyze contingent and necessary propositions. Although Aristotle does not directly address this subject, his philosophy provides a suitable framework for exploring the problem of divine foreknowledge and developing a response.

3. Iamblichus’ Principle in Ammonius’ Commentary to De Interpretatione 9

Ammonius Hermiae, a Neoplatonist commentator of Aristotle, educated in Athens under Proclus and later on head of the Philosophy School of Alexandria in VI a. D, writes the first extant commentary to Aristotle’s De interpretation (cfr. Griffin 2016, pp. 394–400; Rego 2025, pp. 13–17). He might be the first to connect Chapter 9 with divine foreknowledge, inaugurating a tradition in which Boethius and Aquinas will follow. The Neoplatonists attempt to save both divine foreknowledge and contingency in the sublunary world, as Torrijos Castrillejo (2020, p. 154) points out. Ammonius is a pagan Neoplatonist who seeks to harmonize Plato and Aristotle in his interpretations (cfr. Torrijos Castrillejo 2020, p. 154).

Ammonius’ commentary reflects De interpretatione 9’s structure, as the following list will show

• Truth or falsity in future contingent propositions (Ammonius, In de interp. 9, pp. 129,5–130,26).
• Relevance of the subject for science and human life (130,27–131,19).
• Arguments against contingency.

  iii.a

  The reaper (131,20–132,7).

  iii.b

  The gods’ knowledge of the world (132,8–135,11).

• The degrees of knowledge and the refutation of the argument based on divine knowledge (135,12–137,11).
• Counter-argument against necessity in human discourses (137,12–138,10).
• Convertibility of propositions and events and a new argument.

  vi.a

  Convertibility of propositions and events (138,11–141,30).

  vi.b

  Three senses of the contingent (141,31–145,19).

• Final counter-argument against determinism.

  vii.a

  Nature does nothing in vain and human deliberation (145,29–151,8).

  vii.b

  Contingency and being in potency (151,10–152,11).

• Two kinds of necessity in propositions (152,33–154,20).

After presenting the argument of the reaper, Ammonius introduces a brief theological section into this analysis, absent in Aristotle’s arguments for contingency. These are sections in which Ammonius presents, on the one hand, the divine knowledge of the world as the perfect and unique knowledge of the multiple and imperfect, and, on the other hand, the theory of the diverse degrees of knowledge applied to divine knowledge, the so-called ‘Iamblichus’ principle’ (cfr. Torrijos Castrillejo 2020, pp. 154–55). This is an occasion on which we can see how an interpreter of Aristotle considers it to be legitimate to go beyond Aristotle’s words, and to make use of other doctrines—both those known to Aristotle, such as those of his predecessors and others which he did not know– in order to explain the compatibility between divine foreknowledge and the existence of the contingent events.8

3.1. Ammonius and the Divine Foreknowledge of the Contingent

After presenting Aristotle’s doctrine on the truth or falsity of future contingent propositions [cfr. Ammonius, In de interp. 9, pp. 129,5–130,26] and having stressed the importance that this matter has for the whole human life (for without contingency, without freedom, any human effort would be senseless) [cfr. pp. 130,27–131,19], Ammonius addresses two arguments against contingency. The first, a logical argument, is that of the reaper. Ammonius solves it by focusing on the adverb ‘maybe’ (τάχα) and how it modifies the verb. If the verb expresses the action with determinacy, the supporters of this argument are committing the fallacy of ‘begging the question’. If, however, the verb means the future contingent action, then contingency is affirmed (cfr. pp. 131,31–132,7).

While the first argument is logical, the second is more grounded in reality (πραγματειώδης).9 It is constructed on the perfection of the gods and the necessary perfection of their knowledge. In this sense, we consider that for Ammonius, the problem of divine foreknowledge of contingent future events is not only epistemological but also of an ontological nature.10 As we have seen, Aristotle does not address this topic; yet, Ammonius is moved to do so because those who misunderstood divine providence went so far as to think that divine Fate determines the generation of the world’s beings, making the gods responsible for our misdeeds [cfr. Ammonius, In de interp. 9, pp. 131,10–19].

The first thing Ammonius does, then, is to establish the epistemic ground on which this matter is defined: it is a matter for theology or first philosophy11 (in reference to Aristotle’s terminology when referring to metaphysics [cfr. Aristotle, Metaphys. VI 1: 1026^a10–22]). The theological question that needs to be addressed is if everything is governed in a determinate way by the gods, or if there is room for contingency:

“In fact, the theologian inquires in which manner do the gods through providence direct all things that are in the world, whether all the things that generate, generate in a determinate manner and by necessity […] or whether there are certain things that occur contingently […].”12

Curiously enough, the rest of the discussion in this section will center on the divine governance and direction of the world, rather than on the gods’ knowledge of those events. While of course these governance and knowledge are interrelated aspects of the relation between the divine and the world, Ammonius seems more concerned with the compatibility of divine foreknowledge and contingency than with divine government and necessity (at least in this section). The reason may reside in the fact that Ammonius presupposes all along a final counter-argument against necessity, which he presents at the end of the chapter (cfr. Ammonius, In de interp. 9, pp. 145,29–151,8). In effect, the evidence of human deliberation and the fact that nature does nothing in vain are sufficient to shift the initial question from whether the gods govern the world in a determinate manner to whether the gods know the future events determinately.

Consequently, Ammonius first presents three options regarding divine knowledge of the future contingent events: (1) the gods have a determinate knowledge (ὡρισμένως ἴσασι), or (2) they have absolutely no notion, or (3) they have indeterminate knowledge (ἀόριστον γνῶσιν), just like us.13 The second option is quickly abandoned because it is impossible that the gods, immaterial intelligences,14 could ignore anything about the beings they guide and regulate (cfr. Ammonius, In de interp. 9, p. 132,13–19). Additionally, Ammonius affirms that, on one hand, the nature and order of the world are not spontaneously generated and, on the other hand, that the leisure of the gods is not affected by the government of the world, because the gods are not like us. Rather, the gods are like the king sun, who effortlessly illuminates the entire visible world, with its rays reaching all bodies. In effect, the gods benefit every single being except those who, due to their malice, voluntarily reject their beneficent action, such as the ones who hide from or close their eyes to the sun. These, nevertheless, are still subject to the divine punishment and correction (cfr. pp. 132,19–133,12). To support this argument, he cites Plato’s Athenian Stranger, who says that there is no place where the wrongdoer may hide to avoid the punishment of the gods.15

After resorting to the sun as a model of how the divine can relate to the world of generations, Ammonius rejects options (2) and (3):

“[…] it is not possible either that the gods ignore our affairs nor that they have an indefinite (ἀόριστον) knowledge about them, as if they were making conjectures (εἰκάζοντας) about their outcomes.”16

He not only cites several important authorities to support this rejection but also appeals to common, incontrovertible notions about the soul. The authorities cited are important because they demonstrate agreement across three stages of Greek philosophy: first, one of the most important Presocratics, Parmenides; then Plato; and finally, Aristotle himself (cfr. Ammonius, In de interp. 9, p. 133,16–24).17 But what is the common doctrine in these authors that enables Ammonius to affirm the determinate manner of divine knowledge? These authors commonly hold that, among gods, there is neither past nor future since they are eternal.

Regarding Parmenides, Ammonius says that this doctrine is to be found not only in Plato’s works but also directly in Parmenides’ words. Blank (Blank 2013, p. 123 nn. 31–32) identifies some of these passages: In Plato’s Parmenides, the One has no age, since it is neither older (πρεσβύτερον) nor younger (νεώτερον) nor of the same age as anything (τὴν αὐτὴν ἡλικίαν) [cfr. Plato, Parm. 140 e ff]. In Parmenides’ fragment number 8, there is no “was” nor “will be”, but only “is now”.18 In respect to Ammonius’ reference to Plato, Ammonius refers to Timaeus (ὡς ὁ Τίμαιος ἡμᾶς ἐδίδαξε). Again, Blank (2013, p. 123 n. 29), identifies this passage where Plato distinguishes the “was” and the “will be” as forms of time. These forms of time would be mistakenly applied to the eternal substance. Therefore, having rejected past and future forms, only “is” (τὸ ἔστιν) can be properly predicated of the One.19 Lastly, Blank (2013, p. 123 n. 30), connects this with Aristotle’s Metaphys. XII 1072^a24–27, where the first sphere is said to be eternal. Setting aside the possibility that Aristotle may also be referring to something that moves the first sphere,20 Aristotle affirms God’s eternity when he states that the divine life is eternal (cfr. Metaphys. XII 7: 1072^b26–30).

With this, Ammonius stresses the fact that the gods are the principle of all beings (θεῶν ἀρχῆς ἐχόντων πρὸς τὰ ὄντα λόγον [cfr. Ammonius, In de interp. 9, p. 133,25]) and that in them, there is neither past nor future. Rather, they dwell in a “unique eternal now” (ἐν ἑνὶ τῷ νῦν ἐστι τῷ αἰωνίῳ ἱδρυμένα [cfr. p. 133,26–27]) that remains so that everything else may change.21 And so, any conjectural knowledge (εἰκαστικὴν γνῶσιν) is far from the gods and from the perfection of rational life (cfr. p. 133,29–30). In addition, Ammonius affirms, on the one hand, the preeminence of the divine knowledge above our human knowledge, and, on the other hand, the fact that the gods must know their effects and whatever their effects may do. The latter is known only with certain knowledge (cfr. pp. 133,13–134,7).

Indeed, this world is caused by them, since the gods are causes of all things, and they must exert their providence in a manner according to their immutable nature, just as the sun illuminates just by existing, and without any deliberation. Prayer (τὸ εὔχεσθαι), in a sense, as seen in piety and everyday experience, makes manifest the fact that gods order (διατάττεσθαι) the contingent events (τὰ ἐνδεχόμενα) and that they have a definite knowledge (ὡρισμένως γινώσκεσθαι) of their development:

“[…] it is evident that we must say that all contingent things are established by the gods and that their outcomes are determinately known to them”.22

This leads us to recognize that, more so among flowing things than among eternal things, it is necessary to have “a great demiurgic and provident cause that always exists in the same way”,23 without which the world of generation and corruption can neither exist, be preserved, nor be ordered.

This strong affirmation of divine providence, however, sets out the basis for the argument against contingency that Ammonius presupposed all along, because it could end up simplifying the options into only two: either (1) the gods have a determinate knowledge of things, which the gods foreknow, and, therefore, the contingent does not exist, or the gods (2) do not know things, or, at most, returning to option (3), they know them without being sufficiently concerned with them. But (2) and (3) have already been ruled out. Therefore, it would appear that the only remaining option is (1) foreknowledge, and thus the contingent (τὸ ἐνδεχόμενον) would disappear (cfr. Ammonius, In de interp. 9, pp. 134,8–135,11).

3.2. The Degrees of Knowledge and the Refutation of the Argument Based on Divine Knowledge (135,12–137,11)

Ammonius refutes this last argument against the contingent due to divine knowledge of the world by employing the degrees of knowledge. Ammonius attributes these degrees to Iamblichus, but Blank (2013, p. 123 n. 33), identifies a precedent for this distinction in a text by Proclus: De providentia et fato 64 (cfr. also, Mignucci 2013, p. 75; Baltzly 2019, p. 42). Indeed, if we look into this passage, Proclus affirms that even if what is known is indeterminate, a determinate knower will know with determinacy:

“If the knowable is indeterminate and the knower determinate, the knowledge is not made indeterminate by the knowable, but rather it is determined by the knower.”

τοῦ οὖν γνωστοῦ ὄντος ἀορίστου, τοῦ δὲ γινώσκοντος ὡρισμένου, οὐ διὰ τὸ γνωστὸν ἀορισταίνει καὶ ἡ γνῶσις, ἀλλὰ διὰ τὸ γινῶσκον ὁρίζεται.

(Proclus, De prov. et fato, ed. Boese, 64,4–6, p. 169)

And this applies even more to divine knowledge because they know “determinately what is indeterminate” (ὡρισμένως τὰ ἀόριστα [ibidem, 64,10, p. 169]).

Relying on Timaeus’ and Parmenides’ understanding of divine knowledge, Ammonius stresses divine transcendence and omniscience. The gods know the temporal, eternally; the divisible, indivisibly; the manifold, unitedly; and the generated, ingenerately (cfr. supra notes 15 and 16).24 Such is the distance between the temporality of the world and the eternity of the divine that the gods are not only unaffected by the “was” and “will be” of the universe but also, neither is their “is” like the temporal “is”. This reinforces the possibility that their divine essence is not constrained by the “was”, “is” and “will” that structure the knowledge of the past, present, and future of things in the world of generation and corruption.25

Let us consider the divine present referred to by the verb “is”. At this point, we notice that Ammonius has taken a further step to Parmenides, Plato, and Aristotle. Indeed, although all of them deny that the “was” and the “will be” can be predicated of the divine, Parmenides and Timaeus (or Plato) nevertheless still recognize the possibility of predicating the “is”. Ammonius goes further and denies the possibility of predicating the temporal “is” of the gods. Their “is” is different: it is related to the eternal.26 By affirming this, Ammonius considers that he is explaining the true meaning of Parmenides’ words.

Therefore, it is only natural that Ammonius makes use of this Iamblichus’ distinction. How can the determinacy of the divine knowledge coexist with the indeterminacy of the future contingent events? It is by knowing as to which kind of knowledge this relation of knower and knowable belongs. The solution that Ammonius proposes is, as per Iamblichus, that there are three different degrees of knowledge. These degrees refer to the relationship that the subject of the action of knowing has regarding its object of knowing.

The criterion for the degrees of this relationship is the level of perfection. The ontological dignity of the knower may be superior, identical, or inferior to the ontological dignity of the known. In the first case, the ontological dignity and intelligibility of the act of knowing will be superior to those of the object known, as is the case when the human mind knows singular realities, elevating them to a universal state: the knowledge is superior to the object known. In the second case, the ontological dignities of the knower and of the object known are identical or congruent, as when we humans examine ourselves introspectively, knowing our own essence. In the third case, the cognitive potency is inferior to the object known, as when we humans contemplate the divine and the way the gods govern the world (cfr. Ammonius, In de interp. 9, p. 135,12–32).

When we apply these degrees of knowledge to a divine and transcendent knower, such as the gods, we find a way to refute the dilemma posed by the second argument that forced us to choose between providence and contingency. This dilemma only holds as long as the determinate knowledge of the gods transfers its determinacy to its object of knowledge, reducing contingency to a mere illusion. But Iamblichus’ distinction permits us to understand option (1) in a different way: the known is not transformed by the cognitive power. Here, indeed, we are working with the first degree presented by Ammonius: the relation between the contingent and the divine knowledge is similar to the one between human knowledge and singular things. It is a superior power, an excelling one, in this case, which knows a clearly inferior object. The known, which is indeterminate, is inferior to the knowledge, which is determinate:

“Yet they know the contingent in a manner superior to the nature of those [contingent things]. For that reason, having an indeterminate nature and being possible either that they happen or not, we must say that those [the gods], since they anticipate the knowledge of them in a superior manner than their [of the contingent] nature, know them determinately.”

γινώσκειν μέντοι τὰ ἐνδεχόμενα κρειττόνως τῆς αὐτῶν ἐκείνων φύσεως, διόπερ ταῦτα μὲν ἀόριστον ἔχειν τὴν φύσιν δύνασθαί τε καὶ ἐκβαίνειν καὶ μὴ ἐκβαίνειν, ἐκείνους δὲ ἅτε κρειττόνως τῆς φύσεως αὐτῶν τὴν γνῶσιν αὐτῶν προειληφότας ὡρισμένως καὶ ταῦτα εἰδέναι.

(Ammonius, In de interp. 9, p. 136,11–15)

Iamblichus’ distinction was applied to human knowledge. Yet, magisterially, Ammonius applies it to divine knowledge. If we are capable of universally knowing something that has an individual nature, without affecting its nature, how much more will the divine be able to know the contingent, indetermined things that may occur or not, in a determinate way, without affecting their indeterminacy? If we, imperfect knowers as we are, may know universally what is particular, why would the gods not know determinately what is indeterminate in itself? If we can achieve this intellectual operation, and we can, how much more will the gods be able to know in a godly manner, that is, determinately, the contingent, without altering the nature of the contingent?

Ammonius recognizes that to understand these distinctions, we need metaphysical instruction, as the references to Parmenides and Plato had shown. For that reason, he presents another argument based on a common human experience. In medical affairs, the results are always contingent; we cannot guarantee the outcome of a particular medical treatment. However, when death or healing follow necessarily from certain causes, physicians dare to anticipate the outcome of the process, whether it be death or health. If, in some cases, human science may predict certain contingent outcomes, how much more should the absolutely transcendent divine intelligences know the contingent (cfr. pp. 136,1–137,11)?

Lastly, Ammonius addresses an objection. If the gods do know the future in a determinate way, why do the oracles fail, or, at least, are imprecise and ambiguous? To answer this objection, Ammonius offers two reasons. The first one, relying on Syrianus, is that we must not confuse the prophetess’s knowledge with the gods’ knowledge. That is why he says that “in effect, what is illuminated is not as what illuminates”.27 And in the second place, the ambiguity of the oracles might be willed by the gods themselves, because they want us to use our intelligence to interpret them (cfr. pp. 137,12–138,10).

At this point, we can address a question raised by Sorabji (2013, pp. 5–7), according to whom there is a problem with foreknowledge, of which Ammonius does not seem to be very conscious. If the gods can know nothing as past or future, because in them there is no past or future, and their knowledge of future contingent events is both “infallible” and “irrevocable”, then the future is “inevitable”, and the deterministic position wins. By setting divine knowledge outside of the temporal past and future, Ammonius avoids foreknowledge (a term which implies being inside time) and thus also avoids ‘irrevocability’ of divine ‘knowledge’, while preserving its ‘infallibility’. However, Sorabji affirms that this thesis is incompatible with sustaining divine omniscience, and Ammonius would not have seen the problem. Sorabji makes a fine point showing the inadequacy of the term “foreknowledge” to describe a knowledge that is not restricted to the temporal succession of human knowledge. Notwithstanding that, we have to bear in mind that all along this section, Ammonius is presupposing the transcendence of divine knowledge, as it shows in the manner in which he differentiates this human and natural “now” from that divine “now”. In this sense, it might be necessary to presuppose that all vocabulary predicated by Ammonius of the gods needs to be considered as a human way of expressing something transcendent. In consequence, the use of the term “foreknowledge” would be a kind of metaphor to express “temporally” an atemporal and determinate knowledge of future contingent events.

4. Aquinas’ Commentary on De Interpretatione 9

Thomas Aquinas, as does Ammonius, dedicates a section of his commentary to the relation between the divine and the contingent. Indeed, since God is his knowing and willing (“nam intelligere Dei et uelle eius est ipsum esse ipsius” [Thomas Aquinas, In Periherm. I lect. 14, p. 77 l. 341–342]), with his knowing, he knows every knowable object (“suum intelligere et suum intelligibile comprehendit omnem cognitionem et omnem cognoscibile” [cfr. p. 77 l. 345–347]), including the contingent, and with his willing he wills every good (cfr. p. 77 l. 341–355). However, if put this way, everything may seem to occur by necessity due to divine providence (cfr. p. 77 l. 356–364). However, making this assumption depends on treating divine knowledge and will as if they were like ours, when in fact they are very different (cfr. p. 77 l. 365–368).

As Ammonius did, Aquinas sees the need to place the divinity in a transcendental realm.28 To show the degree of difference between human and divine knowledge of the events that develop in time, Aquinas makes use of an example based not in the category of time, but in the category of place. If we want to understand how God relates to past, present, and future events, we must not view these events within the limits of time, but rather step out of time, since God transcends time.29 If we think spatially, we might compare temporal events to different people walking on a road. If we are inside the place, walking on the road, some men will precede us, and others will follow. We might see those who are beside us and some who precede us yet not see those who are behind us. God’s knowledge, instead, could be compared to the vision of a man in a high tower with a view of the entire road, seeing every traveller at once. To him, there would not be a difference between the first and the last of the travellers.30 We, humans, know present things when they are existent in act and somehow perceptible by sense; we know past things when we know things as remembered; and we do not know future things in themselves because they do not yet exist. However, we may know future things in their causes: with certainty, if they are completely determined; with conjecture, if the most probable outcome is their occurrence. If they are of those things that equally may or may not occur, however, we do not know them at all, because we can only know something as long as it is in act, says Aquinas, basing his statement on Aristotle’s Metaphysics IX (cfr. Thomas Aquinas, In Periherm. I lect. 14, pp. 77–78 l. 369–414).

But God is not limited by the perspective of the road. Rather, from the point of view of the tower, as if from the summit of eternity (“quasi in arce aeternitatis constitutus”), his gaze sees all, and what is future, he sees not in its cause, but in itself. He is absolutely outside the order of time, seeing everything eternally, although it occurs within time.31 As we can see, the doctrine of the absolute transcendence of the divine in relation to this world, on which Ammonius’ argument rested, is also present in Aquinas.

We have to bear in mind that the shift from a temporal to a spatial explanation implies a different kind of explanation. When Ammonius affirms that the divine substances’ “now” is different from our “now”, he is not making a metaphor; he is affirming a metaphysical thesis, according to which the gods are not limited beings as the beings of the sublunary world. On the other hand, when Aquinas proposes the image of the tower and the road, he is making a metaphor to describe the connection between eternity (the gaze from the tower) and time (the past, present, and future). It is important to understand that the vision from the tower represents a reality that is not temporal, as the travellers on the road, and, therefore, it is not only “out of time”, but also “out of space”, so to speak. In consequence, this metaphor does not challenge Ammonius’ interpretation, but rather complements it, as an example or metaphor that tries to represent in an image what the metaphysical thesis of divine transcendence means. Similar is the role of the metaphor of the king sun, which Ammonius provides in his commentary, with which he also seeks to express the causal relation between the gods and the creatures from our world.

Although Aquinas does not reproduce Ammonius’ distinction of the three degrees of knowledge, some aspects of this doctrine are recognizable in the following comparison that he makes. Indeed, as Ammonius told us that the act of knowing did not affect the nature of the object known—such as when we know universally the singular thing, we do not alter the nature of the individual thing—similarly, Aquinas says the following: we know the present contingent in a completely certain and infallible manner, as when we see Socrates having a seat. Our knowledge of the present contingent is certain and infallible. God, being in the tower of eternity, sees the entire temporal world as we see the present. And for that reason, it is possible that he also sees the contingent in a completely certain and infallible manner, not only the present contingent, but also the past and future contingent, as he does:

“And, thus, it remains that God knows with complete certainty and infallibility everything that develops in time, and, nevertheless, those things that happen in time are not or develop not by necessity, but contingently.”

“Sic igitur relinquitur quod Deus certissime et infallibiliter cognoscat omnia que fiunt in tempore, et tamen ea que in tempore eueniunt non sunt uel fiunt ex necessitate, sed contingenter.”.

(Thomas Aquinas, In Periherm. I lect. 14, p. 78 l. 432–436)

For Aquinas, the certainty and infallibility of our knowledge of the present do not affect the contingency of the object known. In the same way, God’s completely certain and infallible knowledge of all temporal events does not affect their contingent nature, not even in the case of the future contingents.

Finally, attending to the divine will, Aquinas shows that it is a certain cause of the entire being, in all its differences, whether it be the necessary being or the possible being. Thus, from the same divine will derive necessity and contingency in things, putting some necessary causes for what it wanted to be necessary, and contingent causes for what it wanted to be contingent (cfr. pp. 78–79 l. 437–461).

5. Conclusions

This article presented two commentators of Aristotle who, when faced with the determinacy of the truth and falsity of future contingent propositions in Aristotle’s On Interpretation 9, do not hesitate to turn this logical problem into a strong debate about the compatibility between contingency and God’s foreknowledge. One is Greek and pagan; the other is Latin and Christian. They are Ammonius, head of the Philosophy School of Alexandria, and Saint Thomas Aquinas, friar of the Order of the Preachers, respectively. They face different arguments against contingency in the natural world and argue against them. This article focused on the arguments based on the perfection of divine knowledge, which seems to exclude any possibility of a real contingency in the world. In effect, we have three options. First, that the gods have a determinate knowledge of the future, and there is no room for contingency. Second, that they have absolutely no knowledge of the temporal things. Third, that they have an indeterminate knowledge, like us. Options two and three are compatible with contingency, but they suppose a weak version of divine knowledge. Only the first option supposes divine perfection, but it eliminates contingency. This was the dilemma that Ammonius and Aquinas encountered.

Both commentators sustain a strong notion of divine perfection. Moreover, the complete transcendence of the gods (Ammonius) or God (Aquinas) in relation to the finite and changing world is firmly established by both philosophers, following a philosophical tradition that Ammonius connects with Plato and even with Parmenides. Ammonius goes further: while for Plato, only “is” can be predicated of the divine, Ammonius stresses the difference between the divine and nature, saying that the divine “is” is of an entirely different nature than the temporal “is”.

Since divine knowledge is so powerful, Ammonius makes use of a Proclean distinction that he attributes to Iamblichus (‘Iamblichus’ principle’), in order to save the contingent. As humans, we may relate to our objects of knowledge in three different degrees of perfection. We may know something inferior to us, as when we know the singular things and our knowledge has an intellectual and universal dimension, which is superior to the sensible and singular nature that is known. We may also know something equally intelligible to our knowledge, as when we contemplate our own essence. And we may also have a knowledge that is inferior to the object known, as when we consider the divine providence of the world. In none of those cases, the nature of the knowledge affects or alters the nature of the object known. If we apply this distinction to the problem of divine perfect knowledge and the contingent future events, we can see that we can save both. Here, we have the first degree of knowledge, where the knower is more perfect than the object known. The gods have a determinate (superior) knowledge of the indeterminate future contingent events, without altering their indeterminate nature. Thus, both divine perfect knowledge and imperfect contingent events are saved.

Aquinas also stresses the difference between the divine transcendence of knowledge and will in relation to human knowledge and will. Everything is known to God and willed by Him. However, to avoid the impression that everything happens by necessity, Aquinas likens the temporal “before” and “after” of the succession of events to the “before” and “after” related to place. Thus, he compares our knowledge of the past, present, and future contingent events to the knowledge that a man on a road has of the fellow travellers who walk past him, those who are ahead of him, and those who are behind him. God’s knowledge is not like ours. It is similar to the vision that a man in a high tower could have of the whole road, to whom the first and the last traveller would be seen in a single view of the road. God sees everything, past, present, and future, in a unique act of knowledge. Aquinas states that this knowledge is not like our knowledge, which is by perception, memory, or conjecture, but is in one single vision, seeing each thing in itself, not in its causes, and with complete certainty and infallibility.

Although Aquinas does not recur to Iamblichus’ distinction of the three degrees of knowledge, we still can recognize in his argumentation a similar procedure. He applies Iamblichus’ principle when he compares divine foreknowledge of future contingent events to human knowledge of present contingent events. Just as we know determinately present contingent events, which remain contingent even though we know them determinately, God knows future contingent events determinately, without altering their contingent nature. This is the first degree of Iamblichus’ principle, where the knowledge is superior to the nature of the known. Indeed, whereas our knowledge of the future contingent may not be determinate, our knowledge of the present contingent events is certain and infallible. And this does not affect the contingent nature of the event. If there is no difference between the present, the past, and the future for God, and we can certainly know the present contingent, how much more so can God know not only the present contingent but also the future contingent without destroying the contingent nature of future events? Therefore, God’s knowledge, being of a superior quality than its object, can determinately know the contingent events without destroying their contingency. This subtle use of Iamblichus’ principle further links Aquinas’s commentary to Ammonius’.