Aquinas on Free Will and Intellectual Determinism

Hoffmann, Tobias; Michon, Cyrille

Abstract

From the early reception of Thomas Aquinas up to the present, many have interpreted his theory of liberum arbitrium (which for Aquinas is free will specifically as the power to choose among alternatives) to imply intellectual determinism: we do not control our choices, because we do not control the practical judgments that cause our choices. In this paper we argue instead that he rejects determinism in general and intellectual determinism in particular, which would effectively destroy liberum arbitrium as he conceives of it. We clarify that for Aquinas moral responsibility presupposes liberum arbitrium and thus the ability to do otherwise, although the ability to do otherwise applies differently to praise and blame. His argument against intellectual determinism is not straightforward, but we construct it by analogy to his arguments against other deterministic threats (e.g., the one posed by divine foreknowledge). The non-determinism of the intellect’s causality with respect to the will results from his claims that practical reasoning is defeasible and that the reasons for actions are not contrastive reasons.

We argue, however, that Aquinas is most plausibly seen as (1) an indeterminist in general and (2) an intellectual indeterminist in particular — in other words, that he has an indeterminist conception of liberum arbitrium. We offer separate and original evidence for both theses, while at the same time arguing that his general indeterminism enhances the plausibility of his intellectual indeterminism. In order to show the significance of indeterminism for his action theory, we will also clarify the ways in which he speaks of freedom and analyze the role he attributes to liberum arbitrium in moral responsibility.In section 1, we will explain Aquinas’s concept of the will and two senses in which it is free. For Aquinas, free will in the broad sense does not require alternative possibilities, while free will in the narrow sense, which is liberum arbitrium, is precisely the power to make choices between alternative possibilities. In section 2, we will investigate whether for Aquinas moral responsibility presupposes liberum arbitrium (and hence alternative possibilities). We will first discuss an interpretation that altogether denies liberum arbitrium as a necessary condition for moral responsibility; then we will consider whether Aquinas posits an asymmetrical relation between liberum arbitrium and moral responsibility, according to which blame presupposes liberum arbitrium, while praise does not. In section 3, we will investigate how Aquinas responds to several threats to liberum arbitrium, not only by intellectual determination. We will discuss, above all, his arguments that divine foreknowledge and God’s ‘efficacious will’ do not necessitate human choices. His strategy is never to adopt a compatibilist solution, but always to show that these threats only appear to imply that our choices are necessary. Aquinas hardly discusses the threat of intellectual determinism, but the way he handles other threats of necessitation makes it highly plausible that he would not accept a compatibilist solution to the threat of intellectual determinism either. In section 4, we will review contemporary interpretations of Aquinas that see him either as a compatibilist or as an incompatibilist and — given his belief in liberum arbitrium — as a libertarian; and we will argue against a paradigmatic compatibilist interpretation. Finally, in section 5, we will address intellectual determinism directly: with the help of Elizabeth Anscombe’s analysis of practical reasoning, we will argue that Aquinas’s account of practical rationality is exempt from the threat of intellectual determinism, since practical reasoning, as Aquinas conceives of it, does not lead to necessary conclusions and thus to necessary choices, because practical reasoning is defeasible. One remains always free to revise one’s practical inference by changing one of its premises or by adding a further premise. The meaning of ‘necessity’ determines the meaning of ‘freedom from necessity’; but how precisely Aquinas understands necessity in his discussions about freedom is just as controversial as his understanding of alternative possibilities, for he defines necessity in terms of non-possibility: “‘Necessary’ is that which cannot not be [quod non potest non esse]” (ST 1a.82.1). He also defines necessity as “determination to only one outcome”, that is, the exclusion of any alternative possibility: “Something is called necessary, precisely because it is immutably determined to one outcome [immutabiliter determinatum ad unum]” (QDV 22.6 c. lines 69–70). A fuller account of Aquinas’s conception of necessity will emerge later in this paper. For now, suffice it to mention that, in the context of his discussions of freedom, he analyzes the notion of necessity with the help of Aristotle and Augustine. Building upon Aristotle’s treatment of necessity in Metaphysics 5.5.1015a20–b15, Aquinas distinguishes between (1) intrinsic necessity (which he also calls natural or absolute necessity) and (2) extrinsic necessity. Intrinsic necessity belongs to a thing because of its nature (e.g., it is necessary for a triangle to have three angles that are equal to two right angles). Extrinsic necessity is twofold: either (2.1) something is necessary because of an end (e.g., eating is necessary for life; a ship is necessary to cross the sea), or (2.2) something is necessary because of an efficient cause (e.g., someone who is coerced to do something without being able to do otherwise). From Augustine’s De civitate Dei 5.10, where Augustine explicitly addresses the compatibility of freedom and necessity, Aquinas takes the distinction between natural necessity (which corresponds to Aristotle’s intrinsic necessity) and necessity of coercion (which corresponds to Aristotle’s necessity from an efficient cause). According to Aquinas, precisely because the will is rational appetite, it wills certain things of necessity and other things contingently. Acts of liberum arbitrium are contingent acts. Before discussing these, however, it will prove helpful, in view of the next section, to consider in further depth the will’s necessary acts. Since the will as rational appetite is ordered to the good understood by reason, when something inevitably appears to us as good from every perspective, we cannot but desire it. Such a thing is happiness (ST 1a2ae.10.2 c., QDM 6 c. lines 429–35). Similarly, the blessed human beings and angels — who, according to Christian teaching, see God as he is — necessarily understand that God is the essence of goodness, and for this reason they cannot but love him (ST 1a.62.8, ST 1a.82.2). Furthermore, God, too, cannot but love himself, for the divine will has the divine goodness as its proper object (SCG 1.80 n. 677, QDV 23.4 c., QDP 1.5 c., ST 1a.19.3 c.). In all of these three cases, Aquinas calls the will free and reminds us that only necessity by coercion, but not natural necessity, is incompatible with the will’s freedom. To express the kind of freedom at play in these cases of necessary willing, Aquinas usually uses the term ‘free will’ (libera voluntas). As we have seen, the will is not always able to choose; but, for Aquinas, liberum arbitrium is by definition the ability to choose. Aquinas understands liberum arbitrium not as a power distinct from the will, but rather as the will insofar as it chooses the means to an end (ST 1a.83.4). Sourcehood, which characterizes all acts of the will, thus applies also to liberum arbitrium. In addition, liberum arbitrium, as the power of choosing the means to an end, also implies having alternative possibilities. Furthermore, Aquinas makes liberum arbitrium a necessary condition for moral responsibility. He takes the fact that human beings have moral responsibility for their actions as a given and argues from this premise to the fact that human beings have liberum arbitrium: if they lacked liberum arbitrium, “advice, exhortations, precepts, prohibitions, rewards and punishment would be pointless” (ST 1a.83.1 c.).The fact that Aquinas links liberum arbitrium to precepts and prohibitions, and to rewards and punishments, might suggest that liberum arbitrium essentially concerns choices between good and evil; but this is not in fact the case. While for Aquinas liberum arbitrium must involve alternative possibilities, it is incidental that the choice be between good and evil. In fact, in his view liberum arbitrium is essentially ordered to the good (since it is not a distinct power from the will), and, as we have seen, we can choose something evil only if we falsely take it to be good. He distinguishes between three ways in which liberum arbitrium may regard alternative possibilities: (1) the choice between different means to an end; (2) the choice between good and evil; (3) the change of preference — that is, desiring now one thing and now another. Only the first of these is essential to liberum arbitrium. It is in this way that God has liberum arbitrium (QDM 16.5 c. lines 215–300; see also In Sent. 2.25.1.1 ad 2). In fact, according to Aquinas, God is free to create this world or not, and to create a better or a worse one (e.g., one containing more species of animals — or fewer). Likewise, the blessed in heaven — who, like God, can no longer sin — have liberum arbitrium by which they can choose between different means to an end (QDM 16.5 c. lines 249–52, 266–70). Examples might be the blessed angels who, in their communication with other angels, can choose between different addressees and different topics (cf. ST 1a.107.1 c.), and who presumably can decide on different ways to assist those on earth who are entrusted to their care (cf. ST 1a.113.5 c. and ST 2a2ae.52.3 ad 1).With this clarification in mind, we can say that there may be either compatibilist or incompatibilist interpretations of Aquinas’s LA1 and LA2 and, as a result, of LA3. A compatibilist interpretation of LA1 emphasizes that liberum arbitrium does not exclude the causation of choice by factors independent of the agent. For compatibilism, commonly understood, all the conditions for free agency are compatible with causal determinism, which implies that any choice is ultimately caused by factors that do not depend on the agent. Compatibilism requires that, in order to qualify as a free choice, an act has to be elicited willingly and according to the agent’s beliefs — that is, the causal route to choice must pass through the agent’s mind in a non-deviant way. (In addition, no pathology must affect the agent, the choice must conform to the agent’s own history, it must be sensitive to reasons, etc.) But just as the agent’s desires and beliefs may be caused by factors that are not in the agent’s control, so also with the act of choice itself. In that case, the agent would still be the source of her action. But the libertarian account of LA1 requires more: it requires that the agent be not only the proximate source, but the ultimate source — at least in the order of secondary causality, for, as we have seen in section 1.1, although Aquinas holds that God and not the human will is the absolute ultimate source of human actions, he considers the human will to be the ultimate source among created causes. We will return to the issue of how the exclusion of absolute ultimate sourcehood from the human will accords with libertarianism in section 3.2.As mentioned in section 1.2, for Aquinas, one line of argumentation goes from the existence of moral responsibility to that of liberum arbitrium (LA3) and from there to the availability of alternative possibilities (LA2). But Eleonore Stump has argued that while Aquinas is fully incompatiblist regarding liberum arbitrium, he is only source-incompatibilist concerning moral responsibility. In other words, while Stump agrees that for Aquinas alternative possibilities are required for liberum arbitrium (LA2), she denies that they are also a necessary condition for moral responsibility, and thus she holds that, in Aquinas’s view, PAP and hence LA3 are false. She argues that Aquinas would give the same verdict as Frankfurt in scenarios meant to show that an agent who cannot do otherwise is still morally responsible for her actions. Stump’s interpretation relies on texts in which Aquinas admits that some sins are unavoidable at the very moment when they are performed. If they are sins, moral responsibility is implied (QDM 2.2 c. lines 128–42). If they are unavoidable, alternative possibilities are excluded. Aquinas says in fact that in some circumstances one may sin under the influence of sudden passion, without being able to submit the sudden passion to the control of reason.In the state of corrupt nature [i.e., after the Fall], it is not in the power of liberum arbitrium to avoid all such sins, because they escape its act. Nevertheless, if it makes an effort, it can avoid any one of these movements. But it is not possible that a human being continuously make an effort to avoid such movements, because of the various occupations of the human mind and because of the rest this requires. (QDV 24.12)According to the asymmetrical account of moral responsibility, PAP-Blame is true but PAP-Praise is false. Some philosophers maintain asymmetrical responsibility above all on the basis of the following two considerations: First, it seems that we can praise rightly an agent who performs a good action that the agent could not avoid. Luther’s statement “Here I stand; I can do no other” is often given as a paradigm of freedom, resolution, and moral endorsement of a decision. Susan Wolf has made famous the scenario of a woman who jumps into the water immediately upon seeing a child drowning. Though it might be true that she could not do otherwise, her action is still morally ascribable to her, and praiseworthy. Wolf argues that determination “is compatible with an agent’s responsibility for a good action, but incompatible with an agent’s responsibility for a bad action”. She expresses her view succinctly as follows: Another endorsement of PAP-Praise is found in a discussion of whether one merits in what one desires by necessity. The first opening argument denies this, on the principle that we do not merit by what we desire naturally (QDV 22.7 arg. 1). The argument assumes that what we desire naturally, we desire by necessity, that is, not by liberum arbitrium. The context for this discussion is the desire for happiness, which according to Aquinas is a natural desire. In the response, Aquinas implicitly endorses the axiom on which the opening argument is based — that is, that we do not merit in what we do naturally and hence necessarily. He argues that the desire for happiness in general is not meritorious, while the specific desire for happiness in the divine vision, rather than in, say, bodily pleasures, is meritorious. The reason is that the generic desire for happiness is given by natural necessity, while any specific desire for happiness in this rather than in that depends on the person herself (QDV 22.7 c. lines 61–82).For Aquinas, however, the praiseworthiness of an action is not inversely proportional to its necessity, as the objection states, but rather directly proportional to the goodness of the will from which the action issues. The more firmly the will adheres to the good (stabilis in bono), the more an action is praiseworthy, just as the more obstinate the will is in evil, the more the action is detestable. By means of a vow, a person confirms her intention to fulfill the vow. Hence an action that is done from such a firm intention is more praiseworthy than the same action done without it. Aquinas’s direct response to the objection is this: Aquinas denies PAP-Praise in none of the previous cases. But neither does he ever affirm that praise requires the ability to act either well or badly. In fact, he denies this directly in two further contexts. The first concerns the so-called confirmation of one’s liberum arbitrium in the good by divine grace. As just mentioned, according to Aquinas, one cannot be fully confirmed in the good in this life in such a way that one becomes absolutely unable to sin. This is a privilege of the blessed (QDV 24.9 c.). But divine grace can confirm a person in the good such that sin is made difficult and practically impossible. Aquinas raises an objection: it seems that one has more merit and is more praiseworthy in avoiding sin while being able to sin. He quotes Holy Scripture (Sir. 31:10) speaking of the just man who could disobey the law but did not (QDV 24.9 arg. 5). Aquinas replies that the notion of merit does not require the ability to sin; the ability to sin only makes merit manifest, because it shows that the good (i.e., meritorious) action is voluntary (QDV 24.9 ad 5). This is not a denial of PAP-Praise, however, for it leaves open the possibility that merit presupposes other kinds of alternative possibilities — not between sinning or not, but between doing or not doing a praiseworthy action that is not obligatory. An example for such an action is almsgiving (ST 1a2ae.108.4 c.).It must be said that although Christ’s soul was determined to one outcome within the genus of morality, namely to the good, it was however not determined to one outcome simply speaking. In fact, it could do this or that, or not do it. Hence freedom remained in it, which is required for meriting. (QDV 29.6 ad 1)To show that Aquinas adopts an incompatibilist stance with regard to the threat divine foreknowledge poses to human liberum arbitrium, we will focus on a particularly lucid argument he formulates as one of the opening arguments of his major discussions of divine foreknowledge. It is structured as follows. First, the objection explicitly invokes a principle of transfer of necessity (PTN):(F2)It is not up to X at t1 to prevent that God believed at t0 / believes eternally that X would do A at t2. [Factual premise and fixity of the past]However objectionable this solution may seem, the fact that Aquinas does not adopt compatibilism in his response is all that matters for our overall argument.If the will were moved by another in such a way that it were not at all moved by itself, the acts of the will would not be imputed for merit or demerit. But since by the fact that it is moved by another, it is not excluded that it is moved by itself, as was said, therefore the ground for merit or demerit is not taken away. (ST 1a.105.4 ad 3)Later, in the Summa theologiae, Aquinas repeats the same solution in less detail, but using a new opening argument which formulates the threat of the divine will to contingency according to the structure of the Consequence Argument. Aquinas again begins by invoking a version of the PTN: “That which has necessity from something prior to it is absolutely necessary; for example it is necessary that an animal die because it is composed of contrary parts” (ST 1a.19.8 arg. 3). The divine will’s infallibility is a law-like premise (L): ‘If God wills p, then p.’ The relevant circumstance (C), God’s actual will, is past or eternal, and hence necessary. In conclusion, “it follows that all that God wills is absolutely necessary” (ST 1a.19.8 arg. 3). Aquinas denies this conclusion. He accepts the PTN invoked in the opening argument, but he clarifies that that which derives necessity from something prior has necessity according to the mode of what is prior, which, in the case at hand, may be absolute or conditional necessity. Hence it is not true that everything is or happens by absolute necessity; some things are necessary only conditionally (ST 1a.19.8 ad 3). Conditional necessity is compatible with contingency, for among things that are conditionally necessary, only those with absolutely necessary antecedents are absolutely necessary. Aquinas’s reply thus coheres with his answer in QDV 23.5, which he also repeats in ST 1a.19.8 c.: Because God wants certain effects to happen contingently, he arranged for them contingent causes (such as liberum arbitrium).Aquinas also considers two threats to liberum arbitrium from created causes. One is a threat of external necessitation, which he discusses as causal determination of human choices by the “celestial bodies”. Behind this idea is the cosmological view that all the events in the sublunary sphere, that is, on earth — including human choices — are determined by the constellations of the higher celestial spheres. Aquinas dismisses this threat by arguing that while the celestial bodies may have a necessitating effect on the senses (and hence on non-human animals), they do not necessitate the acts of intellect and will, since intellect and will are immaterial powers that are not directly affected by material objects.Particular goods, in which human acts consist, are not of this sort ... for instance eating this or that food or abstaining from it; yet they have in them that whereby they may move the appetite according to some good that is considered in them; and hence the will is not induced of necessity to choose these. And for this reason the Philosopher explicitly designated the root of contingency in the things done by us on the side of deliberation, which concerns the things that promote the end and which are not [already] determined. (ELP 1.14 lines 506–17) In order to argue for the plausibility of a libertarian interpretation of Aquinas against those who read him as an intellectual determinist, it is crucial to study his account of intellect and will and their interaction, for, according to some, this account implies intellectual determinism. It is notoriously difficult to interpret, at two principal levels. First, Aquinas’s moral psychology of free choice has been interpreted differently, either as intellectualist or as voluntarist. We define intellectualism and voluntarism as follows:The first, IC, interpretation was attributed to Aquinas by his 13th-century critics such as Henry of Ghent. It has also been proposed, at least as a well-grounded interpretation, by Jeffrey Hause. Its main argument is that the intellect does not control its own act, for it is not up to the intellect whether it understands something, whether it assents to a proposition, whether it is convinced or doubtful, etc. Even if it is granted that the will may control whether the intellect thinks of something or not, that the will can turn the intellect’s attention from one object to another, or that the will can make the intellect assent to a non-evident proposition, this is of no avail. For if the intellect does not by itself control its own act, then neither does the will, since, according to the IC interpretation, all activity of the will is fully accounted for by the intellect in the first place.But a judgment concerning this particular action to be done now can never be contrary to our [rational] desire [appetitui]. (QDV 24.2 lines 79–81)One forceful compatibilist interpretation of Aquinas’s account of liberum arbitrium is the one just mentioned, by Pasnau. The problems Pasnau addresses concern Aquinas’s modal theory of choice, not his moral psychology; they are therefore common to IC and VC readings. As Pasnau points out, the fact that our choices are not necessitated can be given a strong, libertarian sense, or a weak, compatibilist sense. The strong sense is that our choices are not necessitated given the previous entire state of the universe. The weak sense, which Pasnau defends, is that human beings do not always and unchangeably do the same thing (p. 231). At the core of Pasnau’s interpretation is the distinction between absolute and conditional necessity. Certain acts of the will occur by absolute necessity, especially our desire for happiness. Other acts of the will, namely our choices of this or that particular good, are subject to conditional necessity (without the necessitating condition being in the agent’s power): “Given the entire state of the universe, including an individual’s higher-level beliefs and desires, a certain choice will inevitably follow” (p. 232). As Pasnau reads Aquinas, the actions of humans and the behavior of non-human animals differ only from the psychological viewpoint, not from the modal perspective, for he takes Aquinas to hold that humans and animals are equally subject to conditional necessity. They differ psychologically, because humans, but not animals, are able to subject their immediate judgments and appetites to higher-level beliefs and desires. Pasnau notes that this makes all the difference for the way in which humans and animals act (pp. 232–3).It is at this point that Aquinas’s moral psychology of liberum arbitrium affects his modal theory of liberum arbitrium. We agree with Pasnau that, for Aquinas, humans (as opposed to animals) can rise above the immediate impact of the external circumstances and of passions by virtue of higher-level beliefs and desires. But unlike Pasnau, we think that, for Aquinas, it is precisely because of the presence of higher-level beliefs and desires that human choices — at least some human choices — are not subject to necessity. For even granting that those higher-level beliefs and desires might be necessitated, for Aquinas they have no necessitating effect on our choices (as we will argue in section 5). Rather, our capacity for higher-level beliefs and desires can always provide our practical reasoning with alternative premises, and for this reason our practical reasoning and hence our choices have alternative possibilities in the strong sense. By contrast, Pasnau argues (without providing any textual evidence) that for Aquinas our choices do follow necessarily from those higher-level beliefs and desires. But, arguably, if Aquinas had held this position, he would have mentioned this precisely in those texts in which he contrasts human and animal freedom.Deliberation differs from practical inference. A practical inference is a logical form, while deliberation is a psychological process, comprising the whole course of investigation and thus consisting of all mental processes that lead to choosing a means (typically a specific course of action) to reach the proposed end. To be sure, many times deliberation is not made consciously and so the practical inferences are not brought to awareness, but the resulting actions can be explained in retrospect by the agent or by an observer as resulting from the end pursued and the beliefs about suitable means to the end. The difference between deliberation and practical inference is also clear in this: a practical inference has only one conclusion, whereas, according to Aquinas, deliberation is precisely that by which an agent has access to different options:Building upon Elizabeth Anscombe’s analysis of practical reasoning, we will now argue that such reasoning is open-ended because it does not operate with a definite set of premises. Thus the agent controls her definitive practical judgment and thereby her choice.It is true that sometimes a simple calculation might suffice to decide what to do in order to achieve a specific end. In this case, one can indeed admit that the reasons necessitate the decision, because they are reasons for doing this (M) rather than that (M′), or reasons for doing this (M) rather than not. These are contrastive reasons. In Aristotelian terms, this is proper to technical reasoning, which operates within a given set of ends (the simplest case would be with one end only), which normally allows for contrastive reasons. A physician makes the (technical) medical decision to abandon the resolution of amputation because a less invasive way of saving the patient is possible. When all the medical considerations of such possibilities have been made, the reasoning is no longer defeasible, and the reasons that remain at the end of the deliberation are contrastive, that is, reasons for doing such-and-such rather than not. Such contrastive reasons indeed necessitate the conclusion. Yet this is not so with practical reasoning, that is, reasoning concerning life in general. When, say, an army physician abandons the goal of saving the patient (the technical end of the physician), she does so because the prospects of recovery are dim or because she is more needed in another place. This deliberation implies considerations of a non-technical sort and introduces ends external to the profession, such as political or military ends. This is not a medical decision, nor does it involve technical reasoning, but it is a properly practical decision. The physician is a human being who can abandon her goal as a physician, and thus she might give up the conclusion she reached when reasoning as a physician. Her contrastive reasons to do such-and-such as a physician were not contrastive reasons overall.Not every cause produces its effect of necessity, even if it is a sufficient cause, because the cause can be impeded so that sometimes its effect does not come about. ... Therefore it is not necessary that the cause which makes the will will something do so of necessity, because it can be impeded by the will itself, either by removing the consideration which makes the individual will something, or by considering the opposite, namely that that which is proposed as good is not good according to a certain aspect. (QDM 6 ad 15)Since the conflict here is between reason and passion, one could of course object that the incontinent act irrationally in that they do not follow their better judgment. But, for Aquinas, the decision of the incontinent, which can be called irrational, objectively speaking — is rationally made, for it is a conclusion that follows upon a sound practical inference. The incontinent could have remained continent by reasoning with the prohibitive major premise, thus arriving at the opposite conclusion. Aquinas’s explanation of the reasoning of the incontinent illustrates nicely how alternative possibilities become available to the agent, defeating her initial practical inference with the introduction of a new (permissive) premise. It also shows that in either case, whether she acted continently or incontinently, the individual acted for some reason.One may object that the absence of contrastive reasons makes choices irrational and that the defeasibility of practical reasoning provides insufficient ground to answer this objection. But libertarians would not find this objection decisive, and they would credit Aquinas’s analysis with being sufficient to account for the rationality of freely made choices. They would in fact argue that demanding contrastive reasons for every choice contradicts the very idea of the agent’s ability to do otherwise. And so they would count Aquinas as a libertarian, in accord with our main argument.