God, Powers, and Possibility in Kant's Beweisgrund Abstract: This paper proposes a novel reading of Kant's account of the dependence of possibility on God in the pre-Critical Beweisgrund. I argue that Kant has a broadly Aristotelian conception of possibility, according to which grounds of possibility are potential grounds of actuality. Since Kant also thinks that the order of the world requires an intelligent being as its originator, he holds that God grounds possibility by his understanding and will. Furthermore, I explore the significance of the distinction between internal and external possibility, the influence of Crusius, and the afterlife of Kant's view in his Critical philosophy. Kant is most famous for rejecting all attempts at proving the existence of God in the Critique of Pure Reason. Notwithstanding this, the younger Kant proposed such a proof himself in The Only Possible Ground of Proof (or Beweisgrund, for short) of 1762. This so-called "possibility proof" has recently received meticulous scrutiny and is, I think, quite well-understood now. In brief, Kant argues that all possibility must be grounded in an absolutely necessary being and then identifies this being with God. 1 However, the way God grounds possibility is controversial to an astonishing degree. Some scholars hold that God is the ground by instantiating possibilities 2 , others that he is the ground by thinking them in his understanding (call this "intellectualism") 3 , and Stang, on his former approach, that God is the ground by his power (Macht), which he calls the "power view" 4 . 5 Newlands rejects all this and argues that Kant does not have any account of God's grounding of possibility. 6 But, recently, Stang has argued that this alleged indeterminacy is on purpose because Kant denies that we can ever comprehend how God grounds possibility, albeit Stang claims that Kant's account is best understood in terms of the power view. 7 I think the main reason for this wide disparity of views is that the conception of a ground of possibility is not well-understood yet. Some readers would like to attribute an account of grounding to Kant that connects contemporary theories of metaphysical explanation with the principle of sufficient reason. While I do not attempt to argue against this view directly (and my account may even be consistent with it), I shall argue that Kant has a different conception of grounding in mind concerning the grounds of possibility. For he accepts a broadly Aristotelian account of possibility, according to which grounds of possibility are potential grounds of actuality. Consequently, God is the ground of possibility because he is the potential ground of the actuality of the world. As a result, Kant explicitly says that God must have an understanding and a will because these faculties are needed in order to be the "sufficient real ground" of possibility (OPGP 2:88). Thus, these are the faculties by which God grounds possibility. 2 I will begin by examining a widely neglected argument in Kant's Beweisgrund that aims to establish that God needs understanding and will in order to ground the order and harmony of the world. In section 2, I show that God needs understanding and will to ground internal possibility (the possibility in accordance with essences), as opposed to external possibility (the possibility in accordance with contingent causal conditions). Section 3 presents the strongest case for this reading: Kant apparently follows Crusius, who has a broadly Aristotelian account of possibility. Crusius holds that grounds of possibility are potential grounds of actuality and also that God grounds possibility by his understanding and will. The task of section 4 is to explore the connection of potentiality and possibility in Kant and how this relates to the distinction between internal and external possibility. Section 5 briefly shows that Kant does not fundamentally change his views on God's grounding of possibility in the Critical period, even though the important discussion of what can be learned from my account as regards the Critical conception of "real possibility" must be deferred to another occasion. 1. God as the Ground of Possibility by His Understanding and Will The first section of Beweisgrund is dedicated to what is known as the "possibility proof", which consists of two main steps. 8 At first, Kant argues that something can be possible only if an absolutely necessary being is the ground of possibility. Then he shows that this being has all the properties that are contained in the concept of God, so this being is God. One of these properties that the absolutely necessary being must have in order to be God is that it is a "spirit" (OPGP 2:88) – that is, a being with understanding and will, rather than a "blindly necessary ground" (OPGP 2:89). Kant briefly sketches three arguments to establish this conclusion. The first argument contends that the divine understanding and will are perfect realities and, as such, must belong to God, the second that God must have understanding and will because the effect cannot be greater than the cause. 9 But my thesis – that God grounds possibility by his understanding and will – turns on the third of these arguments. 10 I will refer to it as the 'Third Argument' and present it in full now: Third, order, beauty, perfection in everything which is possible presuppose a being by whose properties either these relations are grounded, or at least through whom as from a principal ground the things are possible according to these relations. Now the necessary being is the sufficient real ground of all that which is possible external to him; for this reason, even the property must be encountered in him through which, according to these relations, everything outside him can become 3 actual. But it appears that the ground of external possibility, of order, beauty, and perfection, is not sufficient unless a will that conforms to the understanding is presupposed. Thus, it will be necessary to attribute these properties to the Supreme Being. Everybody realizes that, irrespective of all the grounds of the generation of plants and trees, nonetheless regular flowerbeds, boulevards, and such like, are only possible through an understanding which conceives the plan and a will which executes it. In the absence of an understanding, all power [Macht] or generative power [Hervorbringungskraft], likewise all other data of possibility, are insufficient for making the possibility of such order complete. (OPGP 2:88) 11 The Third Argument is, in all its details, extremely difficult and we will unpack it in the subsequent sections. But let us begin with a broad outline of the argument: 1) The absolutely necessary being is the sufficient real ground of possibility.12 2) The empirically observable properties of the world reveal that possibility is grounded by an understanding. 13 3) Thus, the absolutely necessary being is the sufficient real ground of possibility by his understanding. (from 1) and 2)) 4) An understanding is the sufficient real ground of possibility only in conjunction with a will by which that which is thought by the understanding can be caused. 5) For this reason, the absolutely necessary being is the sufficient real ground of possibility by his understanding and will. 14 (from 3) and 4)) This valid argument turns on the premises 1), 2), and 4). Kant takes himself to have already established at this point that there must be an absolutely necessary being as the sufficient real ground of possibility, which is premise 1). 2) is the premise that leads to the conclusion that God must have an understanding; and Kant appeals to the then-popular analogy by human design to defend it: a human designer, craftsman, or architect can only be the sufficient ground of the possibility of gardens and the like if she has not only powers, but also an understanding by which she conceives a plan of regular flowerbeds or avenues. Likewise, so the argument goes, God can only be the ground of the world (with its order, perfection, and beauty) if he has an understanding. 15 Premise 4) argues that God's understanding would not be sufficient to ground possibility without a will by which he can create a world that he conceives in his mind. 16 So his will is needed to make the grounds of possibility complete: without God's will that actualizes the harmony in essences that his understanding makes up, the harmony would be impossible. 17 This does not 4 mean that God decrees by his will that something be possible (which would make Kant a voluntarist about possibility, a view he rejects 18 ), but rather that God can use his will so as to create a world. The reason why his understanding alone is not sufficient for possibility is that this faculty does not explain how something can be actual. This calls for an even closer relation between possibility and actuality than is usually assumed by Kant scholars. But first, we need to see what kind of possibility the Third Argument is about. 2. Internal and External Possibility Following a Leibniz-Wolffian tradition, Kant distinguishes between "internal" and "external" possibility. As we shall see in a minute, internal possibility is the possibility of something considered in itself and can be cognized according to the principle of contradiction. External possibility, by contrast, depends on contingent grounds. One of the confusing aspects of the Third Argument is that Kant speaks of the "ground of external possibility". What makes this so puzzling is that the expression 'external possibility' does not occur elsewhere in Beweisgrund. By contrast, Kant frequently speaks of God as the ground of "internal possibility". 19 What is more, he explicitly says that "there will be talked of no other possibility or impossibility than the socalled internal or absolute one" in Beweisgrund (OPGP 2:78). This clearly means that Kant does not intend to talk about external possibility. 20 The reason for his decision is that he considers external possibility to be unsuitable for the proof of God's existence. 21 One may raise the following objection against my reading of the Third Argument. When Kant says that God grounds possibility by his understanding and will, he only speaks about external possibility, which he needs in order to prove that the absolutely necessary being is a spirit; but Kant does not think that God grounds internal possibility by his understanding and will. In this section, I will argue against this interpretation. As I read Kant, God is the direct ground of internal possibility, but (in most cases) the indirect ground of external possibility. Contrary to the Leibniz-Wolffian tradition, God needs his power not only to ground external, but also to ground internal possibility. Kant's source for the terminology of 'internal' and 'external possibility' appears to be the following passage in Wolff's Cosmology: Internally possible is what is possible regarded in itself, that is, which, considered in itself, does not include any contradiction [...]. Externally possible is what has a determinate cause in the visible world, that is, which is able to exist in it [...]. (Wolff, Cosm 111) 5 As Wolff understands it, external possibility is that which is consistent with the actual causal conditions. Internal possibility, on the contrary, is what is consistent with the essence of the thing. 22 According to Wolff, all intrinsic properties of a thing (as opposed to relations) are either essential properties (essentialia) which constitute the essence of a thing, necessary non-essential properties that are grounded by the essence (attributa), or contingent properties that are merely consistent with the essence (modi). 23 For this reason, the internal possibility of a thing contains all combinations of co-existing and succeeding modes that are consistent with the essence of a thing. 24 In contrast to external possibility, internal possibility can be cognized by the principle of contradiction alone. But cognizing external possibility requires knowledge of the causal conditions of the actual world. For external possibility is the agreement with contingent actual conditions, and Wolff holds that something can only exist if there can be a cause for it. This becomes clear by the notion of a "potential being", which he defines as that which "can have its sufficient ground of existence" in an existing being (Ont 175). Since a substance can only be a ground of actuality by virtue of its powers 25 , a substance is a potential ground of actuality and hence an actual ground of external possibility. However, since everything that is externally possible necessarily exists at one point of time (which is a consequence of Wolff's determinism) 26 , external possibility is co-extensional with actuality 27 . 28 Wolff's distinction harks back to Leibniz, who distinguishes between possibility "in itself" (per se) and possibility per accidens. The former is the possibility of something "in its own nature", the latter the possibility insofar as it depends on external conditions – for example, something may be possible per se but not per accidens because God does not choose to make it actual. 29 Clearly, Leibniz's conception of possibility per se is closely related to Wolff's notion of internal possibility. And although they disagree insofar as Wolff rejects Leibniz's doctrine of preestablished harmony with regard to causality within the physical world, they agree that God predetermines the course of events in the actual world. 30 Therefore, like Leibniz's possibility per accidens, Wolff's external possibility is dependent on what God chooses to happen. It is hard to tell what meaning exactly the expressions 'internal' and 'external possibility' have in Kant, as he does not bother to define them. However, he appears to use 'essence' and 'internal possibility' interchangeably in Beweisgrund 31 ; so I take it that Kant agrees with Wolff at least insofar as internal possibility is derivable from essences. He also, at least in principle, adopts Wolff's conception of external possibility. Kant argues that "conditioned possibility" – which is 6 plainly the same as external possibility – would not be suitable for a proof of God's existence because "conditioned possibility merely makes one see that something can only exist in certain connections; and the existence of the cause is proved here only insofar as the consequence exists" (OPGP 2:157). 32 This means, I take it, that external possibility depends on causal conditions which are themselves contingent and hence do not require the existence of an absolutely necessary being. Thus, "such a proof can only be done from internal possibility" (OPGP 2:157). Nonetheless, there is a notable difference to Leibniz and Wolff. According to Wolff, "therefore something is possible because it is represented by the divine understanding" (VG-Met 975), and Newlands argues convincingly that Leibniz has this view, too. 33 Kant denies that God's understanding alone grounds internal possibility, in part because he has a basically Crusian conception of grounds of possibility. Before we can turn to that, however, we have to address a potential objection that is based on Kant's use of the term 'external possibility' in the Third Argument. As I read it, he wants to prove that God needs understanding and will in order to ground internal possibility. However, in this argument, Kant refers to God as "the ground of external possibility, of order, beauty, and perfection", without explicitly mentioning internal possibility (OPGP 2:88, emphasis mine). This gives rise to the following objection: Internal possibility is required only for the first step of the possibility proof, that is, to show that there is an absolutely necessary being. The task of the Third Argument, however, is to prove that the absolutely necessary being is a spirit, without which it cannot be shown that this being is God. The argument accomplishes this by holding that God grounds external possibility by creating the world, which includes the contingent worldly grounds of external possibility. But to decide that the world has to be this way rather than another, God needs understanding and will. Consequently, the Third Argument does not show that internal possibility depends on God's understanding and will. 34 As sophisticated as this reading is, it would be a mistake to accept it. To begin with, we have just seen that Kant rejects that external possibility is suitable for a proof of God because external possibility is contingent. In fact, this argument would be a backlash into a kind of physicotheology that considers the order and harmony of the world exclusively dependent on God's choice. Such an account would only establish the "moral dependency" of the world. But Kant claims that the world exhibits also "non-moral [unmoralische] dependency" – that is, the harmony of the essences themselves, which is not the result of a choice, is dependent on God. 35 7 The traditional method of physico-theology, which Kant criticizes, proves God's existence by taking only moral dependency into regard. 36 According to Kant, this is wrong – among others, because this can only prove the existence of an "architect and not the creator of the world, who has ordered and formed the material, but not produced and created it" (OPGP 2:123). Even if one takes oneself to have proved the existence of an absolutely necessary being, one cannot infer from the fact that something is externally possible that the absolutely necessary being is the ground of the moral order of the world, since some more mediocre deities could have done the job of giving the world a moral order that depends on their choice as well. 37 Aside from these systematic considerations, the Third Argument itself contains textual evidence against the objection. Kant routinely associates "order, beauty, perfection" (and the like) with internal possibility for the reason that these properties of the world belong to its non-moral dependency. 38 When he speaks about God as "a being by whose properties either these relations are grounded, or at least through whom as from a principal ground the things are possible according to these relations" (OPGP 2:88), I take this to mean that God is not only the ground of the perfect harmony of essences, but also of all essences individually, as they are the relata of the harmony relation. So the Third Argument talks about God as the ground of internal possibility. The question remains, though, why Kant writes that God is "the ground of external possibility, of order, beauty, and perfection" (OPGP 2:88). Two viable explanations come to mind. First, the use of 'external possibility' may just be a mistake or misprint. This explanation would not be ad hoc. The term 'external possibility' appears out of a sudden, and the mistake/misprint may have been induced by the occurrence of the phrase "possible external to him" just one sentence earlier. The term 'internal possibility', however, would seem more appropriate in this sentence because the twofold use of 'of' indicates that "order, beauty, and perfection" is appositive to "external possibility". Another explanation would be that, if God grounds all possibility, he must also ground external possibility. Since the creation of the world includes causal relations 39 , on which external possibility depends, God is indirectly also the ground of external possibility. 40 Therefore, God grounds external possibility indirectly by creating a world. Either way, the texts do not support the interpretation that God does not ground internal possibility by his understanding and will. 8 The strongest case for this reading, however, can be made by taking the similarities to Crusius into account, who likewise thinks that God grounds possibility by his understanding and will. So let us have a look at Crusius. 3. Crusius on God, Powers, and Possibility In this section, I want to show that Kant has a largely Crusian approach of God's grounding of possibility. While this section is mainly textual, I will spell out Kant's account in more detail in the next section. It is a crucial feature of Crusius's account of possibility that all possibility has a "sufficient cause" in something that exists: We call possible that which is thought, but does not yet exist, or from the existence of which we as yet abstract. However, if something that does not yet exist is to begin to exist: then this must be produced through an efficient cause [...]. Therefore, that which is real in the possibilities of such things that do not yet exist – that is, which can have an influence in the coexisting and succeeding things – consists in the existence of a cause for a represented thing. And the possibility of such things that do not yet exist is, according to its higher concept, nothing else but the relation of a thing that we do not yet think as existing to an existing thing, by virtue of which the latter is a sufficient cause for the production of the former, which, as of yet, is only thought. (Crusius, E 56) If someone should find this passage difficult to parse, it would be hard to disagree. But the idea is a classical Aristotelian one: possibility is grounded in actuality. More precisely, existing things ground possibility through their powers. If something is possible, there is a "sufficient cause" for it. But this cause is not yet active. I take it that the meaning of "sufficient" is that the cause, once made active, produces the object that is grounded in the powers and, as it were, exists only in thought. 41 Therefore, according to Crusius, something is possible if there is a sufficient but not yet active cause for it. Using Scholastic terminology 42 , he distinguishes between powers that are present but not active and powers that are present and active: One says of that which is to be possible through a power in the first place, when it acts, that it is now present actu secundo, whereas it has formerly only been present actu primo. For this reason, to be present actu secundo means as much as to actually exist, insofar as one considers this existence as something to which one ascribes the actuality of a power. On the contrary, to be present actu primo means as much as to be possible through the already actually [wircklich] present power of a thing that merely does not act yet. (Crusius, E 64) 9 I take it that the only difference between powers that are present actu primo and those that are also present actu secundo is that the latter has been forced to act by a stimulus, whereas the former would act if being forced to act. Crusius holds that "real possibility" – the "possibility outside of thoughts", as opposed to "ideal possibility", or the "mere possibility in thoughts" (E 56) – obtains if something is grounded in powers that are present actu primo. For, in this case, "sufficient causes for the thing are really present [wirklich vorhanden], which only need to come into the state of action [in dem Stand der Action kommen dürfen]" (Crusius, E 56). 43 Crusius's account of possibility in general also applies to God as the ground of possibility. 44 Although Crusius primarily thinks of grounds and possibility in the world, he holds that God is the ground of the possibility of the world because he has the requisite powers to create the world: The ideal possibility of not existing things would not be useful for anything unless ideal possibility did not contain at least as much reality in itself that, for everything that contradicts neither itself nor other given truths, God at least is a sufficient cause if he were to make use of his omnipotence. (Crusius, E 56) This is what Crusius calls "absolutely possibility", which clearly resembles internal possibility. However, Crusius adds to the logical condition that there is no contradiction the condition that God must be the sufficient cause of possibility. 45 Furthermore, he holds that God needs his understanding to create the world: We encounter in the world an orderly and regular connection and sequence of things that obviously leads us to the fact that the world has been formed according to ideas and has an intelligent [verständige] cause. (Crusius, E 221, see also E 268) Since God creates the world by his will 46 , but "[e]very activity of the will already presupposes the understanding", which is "an indispensable ground of the possibility of any willing" (Crusius, E 445), God grounds the possibility of the world by his understanding and will. Seen in this light, the parallels to Kant are striking. Like Crusius, Kant holds that God grounds possibility by his understanding and will. The term Kant uses to indicate that God has the potentiality to act is "power" (Macht) – for example, Kant says that God has "a will accompanied by great wisdom and power" (OPGP 2:116). 47 Furthermore, Kant holds that God is a "sufficient real ground" because God must have the properties "through which [...] everything outside him can become actual" (OPGP 2:88). This suggests that "sufficient real ground" has the same 10 meaning as the Crusian term "sufficient cause", which means a potential ground of actuality. Hence, it is not an exaggeration to deem Kant a Crusian about God's grounding of possibility. 4. Potentiality and Possibility Newlands helpfully distinguishes between two questions that must be settled for any account of how God grounds possibility: Question 1 (Q1): On what in God do modal truths and modal truthmakers depend? Question 2 (Q2): What is the manner(s) of dependence by which modal truths and modal truth makers depend on God? (Newlands 2009: 158) As we have seen, Kant's answer for Q1 is: internal possibility depends on God's will and understanding. With regard to Q2, the answer is: God grounds internal possibility by being the potential ground of the actuality of everything that is internally possible. But we yet have to understand why Kant answers the questions the way he does. This shall be the task of the present section. With respect to Q1, it is clear that this question cannot be answered independently of Q2. If the answer to the latter were: 'God grounds possibilities by instantiating them', then he would ground them by the possibilities themselves. As Yong (2014: 36–8) has pointed out, this would be a circular explanation of the grounding of possibility. But it is also clear that the instantiation account is incompatible with Kant's claim that God does not instantiate worldly properties that would contradict his divine attributes. 48 Rather, God contains the "ultimate real ground of all other possibility" (OPGP 2:83) 49 , and my potentialist reading can explain how God can ground properties that he does not instantiate himself. As a result, God needs to possess capacities that allow him to be the cause of worldly things which instantiate possibilities. Now the question is: is God a "blindly necessary ground" (OPGP 2:89), or is he a "spirit" who, as such, possesses understanding and will (OPGP 2:87)? If God were the former, the "power view" would be true – God would still be the potential ground of actuality by his power, but not by his understanding and will. For Kant, this would not only be a defective account of God, but also render the great harmony of essences impossible. And as regards intellectualism, it is clear that God's understanding alone cannot be the sufficient potential ground of actuality – understanding just is 11 not a capacity that makes things actual. This shows why Kant answers Q1 by identifying the properties by which God grounds possibility with his understanding and will. As for Q2, we need to consider Kant's discussion of (internal) possibility within the possibility proof in some detail. To my mind, it does not get enough attention that Kant does not bother to argue that possibility, and internal possibility in particular, needs to be grounded. Rather, he uses the proposition that possibility needs grounds as an uncontested premise to argue that some being exists that grounds possibility. Kant introduces the concept of possibility by distinguishing between a formal and a material aspect of possibility. 50 The formal aspect concerns whether some predicates are consistent or contradict each other. But the relations of consistency and contradiction presuppose that there are relata that constitute the material aspect of possibility (Kant calls them the "real" or the "data" of possibility 51 ). Therefore, something is impossible either if there is a contradiction or if the data of possibility are not given. 52 Since Kant apparently thinks we can know a priori that something is possible 53 , he infers that something must exist that grounds possibility. 54 But why does Kant think that possibility must have grounds? Some interpretations vaguely understand the grounding relation in terms of contemporary "metaphysical explanation" and hold that possibility must be grounded in this manner in order to minimize "bruteness", that is, to leave only God (and maybe his properties) unexplained. On this reading, the principle of sufficient reason (PSR) demands that possibility be metaphysically explained. 55 However, at this general level it is unclear why we should ascribe such a view to Kant. Presumably, these interpreters base their reading on Kant's proof of the PSR in Nova Dilucidatio, a writing that appeared in print some years before Beweisgrund. Kant accepts two versions of the PSR in this writing, namely "Nothing is true without a determining 56 ground" (ND 1:393), and "No contingent thing can lack a ground that antecedently determines its existence" (ND 1:395). In Beweisgrund, however, he does not endorse the PSR in either form: in his refutation of what he shall later call the "cosmological proof", which attempts to prove God's existence from the fact that there must be an absolutely necessary ground for contingent existents, Kant objects that the proof rests on the PSR: Now the second step to the proposition that this independent thing is absolutely necessary is already much less reliable, as it must be made by means of the principle of sufficient reason, which is still challenged; however, I have no qualms about subscribing to everything so far. (OPGP 2:157) 12 Admittedly, it is not really clear whether Kant has doubts about the PSR himself or whether he just thinks that we should not appeal to the PSR because it would be a controversial premise. 57 But given that he criticizes the cosmological proof for its appeal to the PSR, it would be surprising if he assigned a role to the PSR in the possibility proof. This casts doubt on reading the grounds of possibility in terms of metaphysical explanation. 58 But if the PSR does not do the work, what then? The answer is that Kant has a potentialist account of possibility. On this view, grounds are an essential aspect of possibility – with the exception of God (who and whose properties are not in need of being grounded 59 ), being possible just is to have grounds of possibility. And since the potentialist view identifies grounds of possibility with potential grounds of actuality, being possible just is to have potential grounds of actuality. 60 This can not only explain the parallels to Crusius, but also why Kant gives no argument that possibility needs grounds. For it is just a conceptual truth that possibility has grounds. In the absence of competing explanations, these are strong reasons to ascribe a broadly Aristotelian potentialist analysis of possibility to Kant. With regard to God's grounding of possibility, the question then cannot be why possibility has grounds, but only why God is this ground. Answering this question is, of course, an important aspect of the possibility proof, and I do not further discuss the proof here. Yet, Kant's potentialist account of the grounds of internal possibility may seem to blur the distinction between internal and external possibility. Recall that, for Wolff and Leibniz, internal possibility consists in the consistency with a given essence, whereas external possibility also requires the agreement with actual causal conditions. According to this view, it is sufficient for internal possibility that God conceives the essences in his mind; only external possibility requires that there be a possible causal action that makes an object actual. But if we adhere to Kant's theory, the grounds of internal and external possibility are seemingly the same: they consist in powers that can make something actual. To be sure, this problem does not occur in the case of worldly substances, as their powers can only change the accidents (or modes) of substances, but not their essences and are hence not grounds of internal possibility. 61 But God is not only the direct ground of internal possibility, but in some cases – by the act of the creation of the world (as regards the immediate effect of God's action) or by miracles 62 – also the direct ground of external possibility. Therefore, an explanation is needed as to what distinguishes grounds of internal from those of external possibility. 13 I think this problem can be solved by considering that every actual thing, or state of things, is produced through an action that is itself dependent on contingent causal conditions. But potentiality is not sufficient to make an action possible. Consider first the example of a ball that is at rest, but has the power to roll. Despite of its power, it does not follow that it is externally possible that the ball rolls. For the ball might be located in a universe in which there is no motion at all, so there would not be another object that sets the ball into motion. By analogy, God's understanding and power are sufficient for internal, but not for external possibility because the mere possession of these faculties does not guarantee that an action is possible by which God can make something actual. Leibniz famously holds that God necessarily (qua his omnibenevolence) chooses the best possible world to exist 63 , and Kant defends him. 64 Thus, even though God has the power and understanding to create other worlds, the only world he can will to create is the actual world because this is the best possible world. Therefore, there can be no action that makes other worlds actual, which are hence not externally possible. Thus, the difference between grounds of internal and of external possibility is that the grounds of internal possibility only require potentiality, whereas the grounds of external possibility also need the possibility of an action. I am not suggesting that Kant in fact has this view (he says nothing about the problem), and some people may doubt that this is a particularly good solution. For example, one might object that Kant's model of grounding is inadequate, that it already presupposes the possibility of what God is supposed to ground, or that internal possibility is not in need of being grounded at all (which would undermine the "only possible ground of proof"). This would be criticism of Kant and not of my interpretation. Nonetheless, it is worth pointing out that his account does full justice to his central assumptions concerning possibility. First, it satisfies Kant's view that all possibility is grounded in causal powers (again with the exception of God). Second, the suggested account coheres with the assumption that internal possibility depends on God's essence and not on his choice. 65 It is crucial that internal possibility can be cognized according to the principle of contradiction because internal possibility is derivable from essences. Since internal possibility is the same in all possible worlds, there must be grounds of internal possibility in all these worlds, which is best achieved by an absolutely necessary being. And third, Kant can account for the fact that external possibility is not directly dependent on God's essence. For the grounds of external possibility are either contingent worldly grounds or God's decrees. 14 5. God's Grounding of Possibility in the Critical Period I have argued in this paper that Kant has a broadly Aristotelian account of possibility in Beweisgrund, according to which grounds of possibility are potential grounds of actuality. By way of concluding, I would like to have a brief look at the Critical period. Although Kant does not address the question of how God grounds possibility in his Critical writings, there are at least two passages in his lectures that, taken together, suggest that Kant still thinks that God grounds possibility by his understanding and will. Firstly, we read: For one can think the causality of God, or his capacity to make other things outside him actual, in no other way than in his understanding, or in other words: a being that is self-sufficient can only become the cause of other things outside him by his understanding; and this very causality of the understanding of making the objects of its representations actual is called will. (RT-Pölitz 28:1061) Kant is reported to be drawing a particularly close connection between God's understanding and his will: the understanding is not only a presupposition for his will; rather, the will is the causality of the understanding. This alone does not reveal that Kant holds that God grounds possibility by these capacities or that grounds of possibility are potential grounds of actuality, of course. But we read in another transcript: We represent the real possibility of things as derived from God because everything exists according to God's decree (as ens entium). (M-Dohna 28:698) This does not have to mean that Kant now accepts voluntarism about possibility. Rather, if we combine this passage with the passage from the Pölitz notes, we can adopt a reading that is compatible with the view from Beweisgrund. For God, who is the cause of the world by his decrees, must therefore also have the capacities of understanding and will, by which he is the potential cause of the world, and hence the ground of real possibility. However, I do not intend to make hasty conclusions from transcripts alone, but only want to point out the continuity that can be found here. And we must not overlook that there are also important differences to Kant's account in Beweisgrund. First, it goes without saying that the Critical Kant denies that we can prove God's existence. Second, Kant now thinks that God's understanding and will are, like all divine realities, properties of which we can have no determinate concept, but which we can only describe by analogy with human faculties. That is, we cannot attribute to God the faculties of understanding and will (which would be anthropomorphist), but only faculties 15 analogous to human understanding and will. 66 Third, the Critical Kant says that God is the ground not of internal (or external) possibility, but of "real possibility". But I must defer a reading of Kant's Critical conception of real possibility and what it means for the relation of God to the world to another occasion. This enterprise shall be as difficult as it is crucial. 67 References Abaci, Uygar (2017): "Kant, The Actualist Principle, and The Fate of the Only Possible Proof". Journal of the History of Philosophy 55/2, 261–291. Abaci, Uygar (2019): Kant's Revolutionary Theory of Modality. Oxford. Adams, Robert M. (1994): Leibniz: Determinist, Theist, Idealist. Oxford. Adams, Robert M. (2000): "God, Possibility, and Kant". Faith and Philosophy 17/4, 425–440. Aristotle. De Anima. Translated by Robert Hicks. Cambridge: Cambridge University Press, 1907. Baumgarten, Alexander G. (M): Metaphysica. Reprinted in vol. 17 of the Akademie-Ausgabe. Boehm, Omri (2014): Kant's Critique of Spinoza. Oxford. Borghini, Andrea and Williams, Neil E. (2008): "A Dispositional Theory of Possibility". Dialectica 62, 21–41. Chignell, Andrew (2009): "Kant, Modality, and the Most Real Being". Archiv für Geschichte der Philosophie 91, 157–192. Chignell, Andrew (2012): "Kant, Real Possibility, and the Threat of Spinoza". Mind 121/483, 635–675. Chignell, Andrew (2014a): "Kant and the 'Monstrous' Ground of Possibility: a Reply to Abaci and Yong". Kantian Review 19/1, 53–69. Chignell, Andrew (2014b): "Can Kantian Laws be Broken?" Res Philosophica 91/1, 103–121. Crusius, Christian August (E): Entwurf der nothwendigen Vernunft-Wahrheiten, wiefern sie den zufälligen entgegen gesetzet werden. Reprint of the edition Leipzig 1745. Hildesheim: 1964. Dunlop, Katherine (2018): "The origins and 'possibility' of concepts in Wolff and Kant: Comments on Nicholas Stang, Kant's Modal Metaphysics". European Journal of Philosophy 26, 1134–1140. Fisher, Mark, and Eric Watkins (1998): "Kant on the Material Ground of Possibility: From "The Only Possible Argument" to the "Critique of Pure Reason"". The Review of Metaphysics 52/2, 369–395. Hoffer, Noam (2016): "The Relation between God and the World in the Pre-Critical Kant: Was Kant a Spinozist?" Kantian Review 21/2, 185–210. 16 Insole, Christopher (2011): "Intellectualism, Relational Properties, and the Divine Mind in Kant's Pre-Critical Philosophy". Kantian Review 16/3, 399–427. Jacobs, Jonathan D. (2010): "A Powers Theory of Modality: or, How I Learned to Stop Worrying and Reject Possible Worlds". Philosophical Studies 151, 227–248. Kanterian, Edward (2018): Kant, God and Metaphysics: The Secret Thorn. London. Leibniz, G.W. (Con): Confessio Philosophi: Papers Concerning the Problem of Evil 1671–1678. Transl. and ed. by R. Sleigh. New Haven, 2005. Leibniz, G.W. (Con): "Mondadology". In Leibniz: Monadology and Other Philosophical Essays. Transl. and ed. by P. Schrecker and A. Martin Schrecker. Indianapolis, 1965. Lin, Martin (2012): "Rationalism and Necessitarianism". NOÛS 46/3, 418–448. Nachtomy, Ohad (2012): "Leibniz and Kant on Possibility and Existence". British Journal for the History of Philosophy 20/5, 953–972. Newlands, Samuel (2010): "The Harmony of Spinoza and Leibniz". Philosophy and Phenomenological Research 81/1, 64–104. Newlands, Samuel (2013): "Leibniz and the Ground of Possibility". Philosophical Review 122/2, 155–187. Pasnau, Robert (2011): Metaphysical Themes: 1274–1671. Oxford. Stang, Nicholas F. (2010): "Kant's Possibility Proof". History of Philosophy Quarterly 27/3, 275–299. Stang, Nicholas F. (2016): Kant's Modal Metaphysics. Oxford. Theis, Robert (1994): Gott: Untersuchung der Entwicklung des theologischen Diskurses in Kants Schriften zur theoretischen Philosophie bis hin zum Erscheinen der Kritik der reinen Vernunft. Stuttgart. Vetter, Barbara (2015): Potentiality: From Dispositions to Modality. Oxford. Watkins, Eric (2005): Kant and the Metaphysics of Causality. New York. Wolff, Christian (GM): Vernünfftige Gedancken von Gott, der Welt und der Seele des Menschen, auch allen Dingen überhaupt ("German Metaphysics"). Reprint of the 11th edition, 1751. Ed. by C.A. Corr. Hildesheim: 1983. Wolff, Christian (Ont): Philosophia Prima sive Ontologia ("Ontology"). Reprint of the second edition, Frankfurt and Leipzig 1736. Ed. by Jean École. Hildesheim: Olms, 1962. Wolff, Christian (Cosm): Cosmologia Generalis. Reprint of the 2 nd edition, 1737. Ed. by J. École. Hildesheim: 1964. Wolff, Christian (TN): Theologia Naturalis ("Natural Theology"), Part 1.1. Reprint of the second edition, Frankfurt and Leipzig 1739. Ed. by Jean École. Hildesheim: Olms, 1978. 17 Wood, Allen (1978): Kant's Rational Theology. Ithaca. Yong, Peter (2014): "God, Totality and Possibility in Kant's Only Possible Argument". Kantian Review 19/1, 27–51. Yong, Peter (2017): "The Grounds of Determinate Thought: Kant's Possibility Proof and the Development of German Idealism". History of Philosophy Quarterly 23/4, 251–269. 1 See OPGP 2:79f., 2:83. – I quote Kant according to volume and page numbers of the Akademie edition. Translations are usually mine, although I considered standard translations. The following abbreviations for titles are used: CPJ = Critique of the Power of Judgment, M-x = Metaphysics x (lecture), OPGP = The Only Possible Ground of Proof, Opt = Essay on Some Considerations on Optimism, Rel = Religion within the Boundaries of Reason Alone, RT-x = Rational Theology x (lecture), VT = On a Recently Raised Tone of Superiority. Wolff and Crusius are quoted according to paragraphs. 2 See Chignell 2009, 2012, 2014a, Boehm 2014. Adams (2000) defends a modest form of Spinozism. 3 See Insole 2011 and Hoffer 2016, who also point out that this view conforms to the views of Leibniz, Wolff and Baumgarten (see Insole 2011: 419f. and Hoffer 2016: 193–5 in particular). 4 See Stang 2010: 280f. 5 For an overview of the grounding of possibility in Descartes, Spinoza, and Leibniz, see Newlands 2013. 6 See Newlands 2013: 177. 7 See Stang 2016: 118, similarly Abaci 2019: 130f. According to Stang (2016: 117f.), we cannot know how God grounds possibility because Kant says that "this thought rises far higher than a created being can reach" (OPGP 2:152f.). However, as Yong points out, this does not mean that it is "strictly unthinkable for us" how God grounds possibility, but only that we have no "causal concept" of it (Yong 2017: 259). 8 For detailed discussion of the possibility proof, see Wood 1978: 64–71, Fisher and Watkins 1998: 369– 80, Chignell 2009, Stang 2010, 2016: ch. 4–5, Boehm 2014: 20–43, Abaci: 2017: 264–70, 2019: 104–31, Kanterian 2018: 207–41. 9 See OPGP 2:87f. 10 This argument is usually neglected. Stang, however, admits that, on a "very natural reading" of the argument, God grounds possibility by his power and understanding (2016: 112). Unfortunately, he rejects 18 this reading without explaining why he considers it mistaken or how the argument should be read instead. Hoffer (2016: 196) uses the argument as evidence that God has an understanding, but ignores the role of God's will. – The location of the argument within the context of the possibility proof, however, is initially puzzling. For the Third Argument seems to appeal to empirical considerations about the order of nature, as Kant does in the second part of Beweisgrund. But since the possibility proof is a priori, it would be problematic to invoke an argument that draws on empirical assumptions. One way to avoid this problem could be that the Third Argument only establishes that the absolutely necessary being must have the capacities to ground the order of nature, but not that this being exists (which already has been established by an a priori argument at this point). However, I am not interested in the role of the Third Argument within the possibility proof here, but only in what it tells us about grounds of possibility. 11 See also OPGP 2:123. 12 Crucially, the absolutely necessary being does not ground his own possibility or the possibility of his own properties. For "his own possibility is originally given", and the absolutely necessary being does not contain the real ground of "the possibility of the most real being himself" (OPGP 2:86). When Kant writes that some possibilities are given in the absolutely necessary being "as a determination" and not as a consequence through him (OPGP 2:79), Kant means that God's determinations are possible because God himself is the absolutely necessary being. Hence, I agree with Stang (2016: 104, 118) against Adams (2000: 438) and Chignell (2009: 181). 13 Because of the perfect harmony that all possibilities must exhibit, I take it that God can only ground them as a whole (see Yong 2014: 39–41). Therefore, it is not possible to single out possibilities that are not dependent on God's understanding. See also section 2. 14 One may wonder whether Kant thinks that there are other necessary conditions for God's will, in addition to his understanding, to cause something. Arguably, this question cannot be answered conclusively. But since all powers necessarily conform to God's will (or else he would not be 19 omnipotent), his will is always sufficient to cause something. Hence, nothing that is relevant for my account depends on this. 15 Metaphysics Herder, which is from about the same time as Beweisgrund, makes basically the same point when it reports Kant to have said that "possibility cannot be the consequence of a choice, but must precede in the representation of the understanding" (28:134). 16 Conversely, the will presupposes the understanding, without which the will could not have a thought of something that it wants to be actualized. This distinguishes a blindly necessary ground – which also could ground possibility – from a spirit. 17 Aside from the quote, this is made clear, e.g., in OPGP 2:91f. 18 See Stang 2016: 113. As Stang points out, Kant argues that "the will makes nothing possible, but only decrees what is already presupposed as possible" (OPGP 2:100, see also OPGP 2:91, M-Herder 28:134). Since Kant talks specifically about decrees, it is clear that he is not denying here that God's will is the ground of internal possibility by its capacity. – I will show later that the Third Argument only concerns "internal possibility"; "external possibility", by contrast, is dependent on God's decrees. 19 See OPGP 2:78, 2:84, and elsewhere. 20 See also Abaci 2019: 108f. 21 See OPGP 2:157, also Chignell 2009: 181, Kanterian 2018: 265. 22 In Theologia Naturalis, Wolff calls internal possibility "possibility considered absolutely", and external possibility is called possibility "considered as it is restricted by the context [in systemata redacta]" (TN 142, see also GM 574). See also Dunlop 2018: 1135, Abaci 2019: 71f. 23 See Wolff, Ont 143, 146, 148, also Abaci 2019: 67f. 24 See TN 144. So it is not true that, as Hoffer (2016: 194) suggests, for Wolff or the Wolffians internal possibility is the same as essence. Rather, internally possible is whatever is compatible with an essence. 25 See Wolff, Ont 881. 20 26 See Wolff, Cosm 112, 114. Determinism means that everything that happens is hypothetically necessary, which rules out free choice and uncaused events. Thus, everything that is externally possible is hypothetically necessary and actual. 27 See Cosm 112, also Abaci 2019: 73. 28 Also see Dunlop's and Abaci's discussion of Wolff's views on possibility (see Dunlop 2018: 1134f., Abaci 2019: 59–74), although I disagree with Dunlop on "possibility in potentia remota", which she reads in a way that seems close to Crusian real possibility. 29 See, e.g., Leibniz, Con 57, also Chignell 2009: 167 n. 20, Stang 2016: 15 n. 11, and the references mentioned there. My views on Leibniz's distinction of the different kinds of possibility have been informed by Adams 1994: ch. 2, Newlands 2010, Lin 2012, and Abaci 2019: 35–54. 30 That Wolff thinks that God predetermines what happens in the world follows from determinism together with the fact that God creates the world. 31 See OPGP 2:92, 2:100, 2:162. 32 I take it that Kant speaks of a "cause" (and not of a ground of external possibility) because he agrees with Wolff that external possibility is co-extensional with actuality. 33 See Newlands 2013: 164–6. 34 I would like to thank xxx for discussion on this kind of objection. 35 See OPGP 2:100. 36 See OPGP 2:117. 37 For helpful discussion of Kant's treatment of physico-theology and the difference between moral and non-moral dependency, see Theis 1994: 127–32, Kanterian 2018: 248–59. 38 See OPGP 2:92, 2:95f., 2:98, 2:99, 2:101, 2:124. 39 See Hoffer 2016: 199–202. 40 We will see in section 4 that God is also the direct ground of external possibility in the case of creation or miracles. 21 41 See Crusius, E 56, 64, 66, 69, 83(a), 83(b), 405. 42 See Robert Pasnau, Metaphysical Themes, 536. The distinction goes back to Aristotle's distinction of two senses of actuality. In De Anima, he argues that "soul is the first actuality of a natural body having in it the capacity of life", whereas the second actuality consists in the specific acts of the soul (De Anima ii 1, 412b5–6). 43 See also Crusius, E 63, 64, 69. 44 This has been pointed out by Stang (2016: 113), who nonetheless does not mention that, according to Crusius, God's understanding and will are needed for his omnipotence. Consequently, it is not true that Crusius is a voluntarist about God's grounding of possibility, as Chignell (2009: 181 n. 41) holds. 45 See Crusius, E 58. 46 See Crusius, E 278. 47 See also OPGP 2:117, 2:126, 2:132, 2:151, 2:159. 48 See OPGP 2:85f. 49 See also OPGP 2:79, 85, 87, and Stang 2016: 107–12. 50 See OPGP 2:77f. 51 See OPGP 2:77f. 52 See OPGP 2:78, 2:79. 53 See Chignell 2009: 164. 54 Some scholars believe that Kant identifies possibility with "thinkability" (see Wood 1978: 66, 68, Fisher and Watkins 1998: 371, Yong 2017: 253f.). But this is wrong. To be sure, Kant makes a strong connection between possibility and thinkability in Beweisgrund, arguing that "everything possible is something that can be thought" (OPGP 2:78). Notwithstanding this, he stops short of identifying possibility with thinkability and even claims that some concepts, which as such are thinkable, may be "deception" (OPGP 2:80) or "empty words" that do not signify possible things (OPGP 2:81). What Kant seems to mean instead is that possible is whatever is legitimately thinkable. And legitimately thinkable is 22 what is given, that is, what is grounded in something actual. For similar views to mine, see Chignell 2009: 168, Stang 2016: 118–20, Abaci 2017: 268f., 2019: 127–9. 55 See Fisher and Watkins 1998: 375 n. 15, Chignell 2009: 157f., Yong 2014: 28. 56 Following Crusius, Kant speaks of "determining" instead of "sufficient" grounds in this context (see ND 1:393). I stick by the usual terminology to avoid confusion. Furthermore, I use 'ground' and 'reason' interchangeably here. 57 When Kant says that he is willing to subscribe to the PSR, this is apparently not much more than a rhetorical move to put this worry aside and proceed to his main objection. Kanterian (2018: 267) argues that Kant in fact takes the PSR to be "unreliable" and already did so in Nova Dilucidatio. But the textual evidence is not straightforward as regards Beweisgrund; and as Kanterian himself notes earlier in his book, Kant accepts and proves the PSR in Nova Dilucidatio (see Kanterian 2018: 133). 58 Another problem about appealing to the PSR is that "the requirement that there be an explanation for real possibility does not dictate what counts as such an explanation" (Abaci 2019: 127). I agree with this. Potentialism about grounds of possibility may well be compatible with the PSR, but it would be only due to the fact that possibility is such that it requires grounds that we need to explain possibility. 59 See OPGP 2:79. Notably, Kant does not say whether his account is disjunctive or whether there is an overarching genus of possibility that applies both to God and the world. Nachtomy (2012: 957–62) argues that Leibniz has a disjunctivist account of existence that is quite analogous to the disjunctivist account of possibility Kant might accept (see Abaci 2019: 58 for a different reading). However, Nachtomy is unable to provide textual evidence that Leibniz consciously embraces disjunctivism, so we should be a bit cautious about this idea, in my view. The same problem applies to Kant – he might be a disjunctivist about possibility, or he might think that there is an overarching genus of possibility. Even so, Kant does not explicitly provide such an account. 60 Providing a compelling account of potentiality is tricky and beyond the scope of this paper; for recent systematic work, see Borghini and Williams 2008, Jacobs 2010, and Vetter 2015. Roughly, potentiality 23 means that, given the right circumstances, something has the intrinsic properties to be a ground of actuality. In the case of God, the right circumstances would be that he decrees to create a world, which would make his understanding and will grounds of the world's actuality; without God's decrees, his faculties are only potential grounds of the world's actuality. 61 Kant appears to endorse Baumgarten's (M 106) claim that essences are necessary and unchangeable (see M-Herder 28: 18). This view is very traditional and has also been championed by Wolff (GM 42, Ont 300). 62 Since the whole world owes its existence to God's creation, but substances cannot be created by worldly substances (maybe with the exception of living beings), worldly substances must be created directly by God. Miracles, on the contrary, "interrupt the order of nature" (OPGP 2:116); they are direct causal interventions by God and Kant clearly does not rule out their possibility. See Chignell 2014b for a helpful discussion of Kant's account of miracles. 63 See, for instance, Leibniz Mon 53–5. 64 See OPGP 2:153f., also his essay on optimism from 1758 (Opt 2:27–35). 65 This helps to refute an objection from Chignell (2009: 181), who argues that powers cannot ground internal possibility because they can only be grounds of external possibility. However, while it is true that worldly powers are only grounds of external possibility (because the existence of substances with these powers is contingent), God exists absolutely necessarily, so his powers can be grounds of internal possibility. 66 See CPJ 5:464n, Rel 6:65n, VT 8:400f.n, also A696f./B724f. Wood's discussion on this matter is most helpful (see Wood 1978: 86–93). 67 [acknowledgments]