Kant’s Principia Diiudicationis and Executionis

Abstract

A core feature of Kant’s Critical account of moral motivation is that pure reason can be practical by itself. I argue that Kant developed this view in the 1770s concerning the principium diiudicationis and principium executionis. These principles indicate the normative and performative aspects of moral motivation. I demonstrate that cognition of the normative principle effects the moral incentive. So, the hallmark of Kant’s Critical account of motivation was contained in his pre-Critical view. This interpretation resolves a controversy about Kant’s apparent eudaimonism in the first Critique and shows that he developed his account of moral autonomy in the 1770s.

1. Introduction

A core feature of Kant’s Critical account of moral motivation is that pure reason can be practical by itself (e.g., CPrR, 5: 31, 42). On this view, pure reason legislates the moral law, which is itself ‘the genuine moral incentive of pure practical reason’ (5: 88). ¹

In recent decades, Kant’s account of moral motivation has received considerable attention. ² To explicate his Critical view on the topic, scholars often appeal to Kant’s distinction between the principium diiudicationis and principium executionis, or principle of adjudication and principle of execution (e.g., Allison 2013: 131; Goy 2007: 348; Guyer 1993: 339, 345; Morrison 2008: 16; Nauckhoff 2003: 47; Timmermann 2007: 42, 170). This distinction, stemming from Kant’s 1770s lectures on ethics, ³ indicates the normative and performative moments of moral motivation: the principle of adjudication is the supreme standard of moral appraisal, the principle of execution – identified with moral feeling – the incentive that moves the agent to act according to the norm. ⁴ Thus, these principles track the cognitive and conative aspects of moral agency. They are important to the development of Kant’s views on moral motivation, because he combines them in his Critical account (Allison 2013: 131; Guyer 1993: 339; Kuehn 2009: 22, 2004: xxxix, 2015: 65; Sensen 2015: 198): the moral law is the supreme moral norm and via respect is ‘the sole and also undoubted moral incentive’ (CPrR, 5: 78).

The standard reading of Kant’s 1770s lectures denies the intimate connection between moral incentive and norm characteristic of the Critical account of moral motivation. ⁵ On this view, the moral incentive is not grounded in cognition of the norm. Thus, Oliver Sensen argues that, at this time, ‘Kant did not hold … that pure reason can be practical by itself’ (2019: 83), and Susan Meld Shell contends that the ‘self-legislating power of reason … is not (yet) sufficient for determining the will (principio der execution)’ (2013: 118). Heiner Klemme claims that ‘there are no traces in the transcript [of the 1770s lectures on ethics] of the idea that pure reason itself effects a feeling in us that constitutes the (subjective) incentive of our moral action’ (2006: 124). Likewise, Michael Walschots asserts that ‘in the 1770s Kant had not yet come to believe a core component of his mature view, namely that moral judgement itself can effect the force capable of moving us to action’ (2022: 246).

In this article, I offer an alternative to the standard reading. I argue that in Kant’s 1770s view pure reason is practical. So, the hallmark of Kant’s Critical account of motivation was already contained in his pre-Critical view.

To develop this interpretation, I begin in Section 2 with Kant’s principles of adjudication and execution in the 1770s lectures on ethics. I argue that the moral incentive is effected by moral judgement: moral motivation is grounded in cognition of the moral law. To succeed, this interpretation must overcome two puzzles. In Section 3, I address Kant’s apparent claims that moral judgement does not effect the moral incentive, their relationship being one of mere external conformity. Such claims, I argue, concern Kant’s view that cognition of the moral law is necessary but not sufficient for acting morally. Then in Section 4 I turn to the second puzzle: Kant’s supposed quasi-eudaimonism. Although Kant correlates the existence of God and reward with the execution of obligation, he nevertheless takes moral worth to consist in acting for the sake of the moral law. The existence of God is a postulate of practical reason. I conclude in Section 5 by discussing the payoffs of my interpretation: it resolves a long-standing controversy concerning Kant’s apparent eudaimonism in the Critique of Pure Reason, and shows – contrary to a prevailing view in the literature – that Kant developed his account of moral autonomy in the 1770s.

2. The moral law and moral feeling

In the 1770s lectures on ethics, Kant claims that the principle of morality ‘must be a single principle emanating from the ground of our will’ (L-E/Kaehler, 21). Moreover, ‘every moral law expresses a categorical necessity’ (p. 27). ⁶ Hence, ‘the moral imperative … commands categorically and absolutely’ (p. 9). Since ‘all necessary rules must be certain a priori, and hence the principles are intellectual’ (p. 27), the principle of morality ‘has its ground in the understanding and can be cognized completely a priori’ (p. 26). ⁷ Thus, ‘the moral principle is a purely intellectual principle of pure reason’ (p. 60).

Significantly, Kant explicates the supreme principle of morality in connection with the principle of adjudication and principle of execution:

We have first to take up two points here: the principle of adjudication of obligation, and the principle of execution or performance of obligation. Guideline and incentive are to be distinguished. The guideline is the principle of adjudication and the incentive that of carrying out the obligation. (L-E/Kaehler, 55–6) ⁸

The principle of adjudication ‘is the norm’ (L-E/Kaehler, 57) and concerns ‘what is morally good or not’ (p. 56): it is the objective standard of moral goodness and depravity. The principle of execution indicates the ‘incentive’ that ‘moves me’ or ‘incites me’ to act according to the moral norm (p. 56). This incentive ‘lies in the heart’ and ‘is moral feeling’ (p. 57). Note Kant’s claim that confusion of these principles has set moral inquiry on the wrong track: ‘insofar as they have been confused, everything in morality has been erroneous’ (pp. 55–6). Thus, the relationship between the moral norm and incentive – in a word, moral motivation – is crucial to Kant’s exposition of the supreme moral principle. ⁹

In what follows, I argue that cognition of the moral norm effects the moral incentive. In order to do so, I first draw attention to a feature of Kant’s mature moral philosophy found in the 1770s lectures on ethics: moral worth consists in acting for the sake of the moral law. Kant correlates an action’s moral worth with its conformity to universality: ‘the morality of the action consists in the universal form (which is purely intellectual) of the understanding’ (L-E/Kaehler, 68). However, mere external conformity ‘to the universal rule’ is not sufficient for moral worth: ‘for morality a good will is required’; thus, ‘our free conduct rests solely on the good will if it is to possess moral goodness’ (p. 33). In this case, ‘our actions [must] occur from a motive of the universal rule’ (p. 65). So, Kant claims that ‘to hold a promise out of satisfaction of sensibility is not moral’; instead, I must make conformity to the universal rule ‘the basis of my actions’, for only then do they ‘arise from the moral principle’ (p. 65).

In order for the action to arise ‘from a pure moral principle’, it must take place ‘because it conforms to the universal rule’ (L-E/Kaehler, 67–8; my emphasis). As in the Groundwork of the Metaphysics of Morals, morally good actions must be performed ‘for the sake of the law’ (G, 4: 390). Acting for the sake of a maxim’s universal form involves having a moral disposition: ‘if I do something because it is absolutely good in itself, then that is a moral disposition’ (L-E/Kaehler, 39). ¹⁰ Thus, ‘all morality is based on the action being performed for the sake of the inner constitution of the action itself; hence it is not the action that makes for morality, but the disposition from which I do it’ (p. 39). This tracks Kant’s distinction between acting merely in conformity with duty and acting from duty: ‘the conformity of the action to the laws out of dispositions and from duty possesses morality’ (p. 55; see also G, 4: 397ff.). ¹¹

Kant identifies the heart with the moral disposition: ‘heart is the principle of the moral disposition’ (L-E/Kaehler, 55). Recall that Kant locates the moral incentive ‘in the heart’ (p. 57). So, moral worth – understood in terms of acting from a moral disposition whereby the moral law is made the basis of one’s action – is connected intimately with the moral incentive, the principle of execution.

What, then, is the relationship between ‘objective motives’ – ‘grounds of what we should do’ – and incentives, or ‘subjective motives’ – ‘grounds of disposition and the determination of the will to satisfy the rule’ (L-E/Kaehler, 51)? ¹² As in his Critical view, Kant maintains that the human will does not necessarily conform to objective principles: ‘the appraisal of the action is the objective ground, but not yet the subjective ground’ (p. 56; see also G, 4: 412; CPrR, 5: 79). Cognition of the objective norm is not sufficient for volition (L-E/Kaehler, 68). Yet, ‘if this judgement moves me to do the action, that is the moral feeling’, that is, ‘the incentive of the action’ (p. 68). By the early to mid-1770s, Kant came to the position, as expressed in the Critique of Practical Reason, that in actions of moral worth ‘the objective determining ground must always and quite alone be also the subjective determining ground’ (CPrR, 5: 72). Specifically, cognition of the moral law effects the moral incentive. Thus, in a famous letter to Marcuz Herz from late 1773, Kant writes that the supreme ground of morality ‘must have the power to move, and therefore, although it is intellectual, it must nevertheless have a direct relation to the primary incentives of the will’ (C, 10: 145). Likewise, in a Reflexion from the early 1770s Kant asserts: ‘The understanding must excite sensibility and as a result it determines the action; thus, the action occurs according to laws of sensibility yet of the understanding as well’ (R 4334, 17: 509). ¹³ Corroborating Kant’s claim in the lectures on ethics that the moral incentive – in the guise of moral feeling – consists in being moved by moral judgement, he notes in a Reflexion from 1772 that ‘the moral feeling follows from the moral concept’ (R 6757, 19: 150), and in another from the same year that ‘the moral feeling arises from moral judgement’ (R 6760, 19: 152).

3. Moral feeling as capacity

So far I have argued that, in Kant’s 1770s view, consciousness of the moral law in moral judgement effects the moral incentive. Thus, the connection between the principle of adjudication and principle of execution bears on moral worth in a way that anticipates Kant’s mature account of moral motivation. However, several passages in the 1770s lectures on ethics militate against this reading, suggesting that the connection between moral incentive and norm is only coincidental. In what follows, I argue that these claims express Kant’s view that the subjective grounds of human volition do not necessarily conform to objective principles. Moral motivation further requires the cultivation of our capacity to be affected by moral judgement.

Preliminary to the discussion, consider the following passage from the 1770s lectures on metaphysics, where Kant appears to deny any motive force of objective principles on human beings: ‘It is a misfortune for the human race that moral laws, which are here objectively necessitating, are not simultaneously also subjectively necessitating’ (L-M/L _1, 28: 258; see also Stark 2004: 68n46; Klemme 2006: 124). However, a close reading of this controversial passage reveals that Kant is not rejecting the motive force of objective principles per se but only denying that cognition of them is sufficient for volition: objective principles are not ‘simultaneously’ (zugleich) subjectively necessitating. ¹⁴ Moreover, in the same paragraph Kant asserts:

An objective necessitation can also be subjective … namely if the mere cognition of the action that it is good moves my subject to perform it; then it is an incentive. If the cognition of the understanding has a power to move the subject to the action merely because the action in itself is good, then this motive power is an incentive which we also call moral feeling. (L-M/L _1, 28: 257–8)

Note the correspondence with Kant’s claims in the Kaehler notes, discussed in the previous section, that the moral incentive consists in being moved by cognition of the objective moral norm (L-E/Kaehler, 70). Consequently, the controversial passage reflects Kant’s view that the human will is ‘morally imperfect’ (p. 29) and therefore not infallibly determined by objective principles.

Alternatively, some passages in the Kaehler manuscript suggest that moral agency consists in bringing our natural feelings into external conformity with the moral law. For example, Kant apparently claims that human beings cannot be moved by objective grounds but can merely habituate themselves to act in accordance with them: ‘The human being has no such secret organization that he can be moved by objective grounds … Yet we can indeed produce a habitus, which is not natural but replaces nature, and becomes habitual through imitation and frequent exercise’ (L-E/Kaehler, 72). ¹⁵ Moreover, Kant appears to equate the moral incentive with coincidence with objective grounds: ‘[a] sensibility that accords with the motive force of the understanding would be moral feeling’ (p. 71). This coincidence, wrought by habit, seems to rest on developing an aversion to actions contradictory to the moral law: ‘Everyone can see that the action is abhorrent, but whoever feels this abhorrence has a moral feeling … if sensibility abhors what the understanding recognizes as abhorrent, this is moral feeling’ (p. 71).

As a result, several scholars take Kant’s 1770s view on moral motivation to consist in merely aligning our natural feelings with the objective moral norm. Thus, Sensen claims that ‘moral feeling is the same as one’s natural feelings being in accord with what reason demands … and it is just the state in which one’s natural feelings support the judgement of the understanding’ (2019: 100). Likewise, Walschots asserts that Kant’s position ‘relegates the intellectual cognition of obligation to a secondary or even an inconsequential role’ because to act morally ‘we need only to form a habit of our feelings’ (2022: 247). Other commentators, recognising Kant’s entertainment of his mature account of moral motivation, contend that he balked at fully committing to this view. So, Henry Allison remarks that ‘Kant was not completely sold on this view’ (2020: 229) and Steffi Schadow supposes that Kant’s ‘position on the “question of incentives” is altogether undecided in this phase of his ethics’ (2013: 205).

Yet, reading Kant this way contradicts his claims, discussed in Section 2, about moral worth and moral motivation. The conformity to the moral principle required for moral worth involves acting for the sake of the moral law, that is, from duty, whereby conformity to universality is made the basis of volition. As shown, this entails acting from a disposition whose principle is the moral incentive effected by cognition of the moral law.

By my lights, this puzzle can be solved by heeding two senses of the term ‘moral feeling’: incentive and capacity. As we have seen, Kant identifies the principle of execution with moral feeling as incentive (L-E/Kaehler, 56–7, 68). Significantly, he also conceives of moral feeling as a ‘capacity to be affected by moral judgement’ (p. 68). This dual function of ‘moral feeling’ remains in Kant’s mature moral writings. In the Critique of Practical Reason, Kant identifies moral feeling with the ‘feeling of respect for the moral law’ (CPrR, 5: 75; see also 5: 85), which serves as the ‘incentive to make this law its maxim’ (5: 76). At the same time, in the second Critique, he calls moral feeling ‘the capacity to take such an interest [i.e., moral interest] in the law’ (5: 80). In Religion within the Boundaries of Mere Reason, Kant identifies moral feeling with an ‘incentive of the power of choice’ and ‘susceptibility to pure respect for the moral law’ (Rel, 6: 27). ¹⁶ Likewise, in the Metaphysics of Morals he equates moral feeling with ‘respect for the law’, considered subjectively (MM, 6: 464), and also calls it a ‘susceptibility of the free power of choice to be moved by pure practical reason’ (6: 400). Despite the terminological tangle, Kant consistently employs ‘moral feeling’ to indicate both the moral incentive and a capacity to be affected by cognition of the moral law. ¹⁷

I submit that Kant’s claims about habit be understood as highlighting the role of moral education in cultivating moral feeling qua capacity. Thus, ‘moral feeling is cultivated’ through ‘long practice’ in which ‘moral motives are strengthened’ (L-E/Kaehler, 205), with which Kant tasks ‘education and religion’ (p. 73). Several aspects of this cultivation described in the Kaehler manuscript parallel Kant’s other writings on moral education. For instance, Kant observes that actions contrary to the moral law must be represented as ‘intrinsically abhorrent, e.g., the child who lies must not be punished but shamed’ (p. 73). Likewise, in the lectures on pedagogy Kant claims that ‘[e]verything is spoiled if one seeks to ground moral cultivation upon examples, threats, and punishments’, since ‘one must see to it that the pupil … not only does the good but does it because it is good’ (Ped, 9: 475); hence ‘[i]f a child lies, for example, it must not be punished but rather met with condemnation’ (9: 480). Moreover, Kant correlates moral cultivation with disgust and abhorrence towards immorality: ‘a disgust, an abhorrence, a condemnation toward it must be developed, as if the child were pelted with excrement; through such frequent repetition, we can arouse in him such an abhorrence to the action, which can become habitual’ (L-E/Kaehler, 72–3). ¹⁸ Similarly, in the Critique of Practical Reason Kant connects moral cultivation with habitual moral appraisal, and ensuant esteem or abhorrence (though sans the figurative reference to throwing feces at children):

frequent practice in recognizing good conduct in all its purity and approving it, while noting with regret or contempt even the slightest deviation from it … will leave behind a lasting impression of esteem on the one hand and abhorrence on the other, which through mere habit of repeatedly regarding such actions as deserving approbation or rebuke would make a good foundation for uprightness in future conduct. (CPrR, 5: 154–5)

So, Kant claims in the Religion that ‘by allowing moral apprentices to judge the impurity of certain maxims on the basis of the actual incentives of actions … duty merely for itself begins to acquire considerable importance in the apprentice’s heart’ (Rel, 6: 48). In a word, Kant’s 1770s remarks on developing abhorrence to immorality through habit are not an explanation of the moral incentive but of the cultivation of our capacity to be affected by moral judgement. ¹⁹

This cultivation is a necessary condition for cognition of the moral law to effect moral feeling qua incentive. Thus, Kant claims that ‘moral feeling must first be made active so that the subject can be moved by moral motives’ (L-E/Kaehler, 86). As a result of the cultivation of moral feeling ‘morality will have the force of incentive’ (p. 205). This view persists in Kant’s mature writings. Hence, Kant’s remarks on moral education in the Doctrine of Method of the second Critique concern the ‘way in which one can make objectively practical reason subjectively practical as well’ (CPrR, 5: 151). Notably, in the Metaphysics of Morals, Kant counts moral feeling among ‘the natural predispositions of the mind (praedispositio) for being affected by concepts of duty’ (MM, 6: 399; my emphasis) and asserts our obligation ‘to cultivate and to strengthen it’, without which ‘the moral vital force could no longer excite this feeling’ (6: 400; my emphasis). So, Kant argues in the Kaehler manuscript for the empirical cultivation of our natural capacity to be affected by moral judgement as a necessary condition to excite the moral incentive. ²⁰

4. The highest good

The second hurdle faced by my interpretation concerns Kant’s apparent claims that divine reward is the moral incentive. The aim of this section is to show that, even in the 1770s, Kant instead takes the existence of God to be a condition of the highest good. So, moral motivation consists in acting for the sake of the moral law, consciousness of which postulates God’s existence. ²¹

To be sure, an extended passage in the Kaehler manuscript suggests a eudaimonistic account of moral motivation:

in performance there must indeed be a third being who constrains us to do what is morally good. However, we need no third being to appraise morality. All moral laws can be correct without such a being. Yet, in execution they would be empty if no third being were able to constrain us to them. Thus, it has rightly been recognized that without a supreme judge all moral laws would be without effect, for in that case there would be no incentive, no reward, and no punishment. Hence cognition of God is necessary with respect to the execution of moral laws. (L-E/Kaehler, 62)

Although the objective moral norm is independent of God, the moral incentive appears to consist in divine reward and punishment. Moreover, this seems to endow moral laws with their obligatory force: ‘God thus appears to be the obligator of moral laws’ (L-E/Kaehler, 61).

Consequently, Klaus Düsing asserts that ‘[t]he moral incentive consists in the hope of happiness in a future world’ (1971: 16–7). Similarly, Kuehn maintains that ‘Kant believed around 1775 not just that morality needs the eudaimonistic component that he later completely abandons’ but also ‘that this eudaimonism is underwritten by God’ (2015: 59); thus, moral motivation is attributable ‘ultimately to a belief in God’ (p. 65). Likewise, Sensen locates the moral incentive in ‘the reward and punishment one can expect because it is commanded by God’ (2015: 197) and claims that, apropos action in accordance with the moral law, ‘if pressed, the Kant of the mid-1770s would have to admit that one is only doing it because it is God’s will’ (2019: 99).

Yet, several contravening claims in the 1770s lectures on ethics reject such a theologically imbued eudaimonism. Thus, Kant denies the moral worth of action performed on the basis of anticipated divine punishment or reward: ‘[i]f we are to execute the moral law out of fear of punishment and the might of God … then we do not do it out of duty and obligation’ (L-E/Kaehler, 64). Likewise, ‘if I act in accordance with the divine will and perform good deeds in order to receive reward from God hereafter, then I did not perform the action from a moral disposition’ (p. 80). So, ‘I must not lie, not because it is forbidden by God, but because it is good in itself … Hence an action must be done not because God wills it, but because it is upright and good in itself’ (p. 39).

Note, too, Kant’s rejection of moral obligation’s dependence on an external will (and therefore God): ‘It may indeed seem that in an obligation we are necessitated per arbitrium alterius; however, I am necessitated by an arbitrium internum, not externum, and thus by the necessary condition of universal will’ (L-E/Kaehler, 37–8). Hence, we are obligated by our own will, not that of another (including God). Indeed, the internal character of moral obligation and moral motivation is part and parcel of Kant’s account of moral worth: ‘if I satisfy my obligation through my own will, then the motive is internal and I do the action from duty’ (p. 80).

In order to resolve the tension between these sets of claims, a few scholars downplay the import of the proposition that moral laws would be empty in execution without God to enforce them. Dieter Schönecker claims that such passages do not reflect Kant’s own view and are not meant to be taken ‘normatively’ but make a descriptive claim that Völker ‘in fact very often … require hope of reward or fear of punishment as an incentive’ (2005: 124). Karl Ameriks argues that Kant’s point here is ‘that the idea of God … might be used as a proper, indirect device to keep human beings who already have moral motivation from losing that motivation in the context of extremely difficult circumstances’ (2010: 44–5). However, these readings are difficult to reconcile with Kant’s explicit claims that ‘all moral laws’ would be empty without God to constrain us to them and that God is therefore ‘necessary with respect to the execution of moral laws’ (L-E/Kaehler, 62).

Appearances to the contrary, even in this early context, the relevant claims about the existence of God pertain not to moral motivation but to the highest good. In the 1770s lectures on ethics, Kant treats the highest good in connection with the ‘ancients’. ²² Yet, this treatment is rife with Kant’s own burgeoning views on the topic. ²³ In particular, the highest good consists in happiness in proportion to worthiness to be happy (L-E/Kaehler, 11–12; see also A810/B838; CPrR, 5: 111, 130). ²⁴ As in his mature view, the concepts of morality and worthiness to be happy are analytically connected (L-E/Kaehler, 111, 113). ²⁵

Kant elucidates this connection apropos reward and punishment, distinguishing between rewards of inducement (praemia auctorantia) and those of requital (praemia remunerantia). Whereas the former are allotted when ‘the action is done solely for the sake of the promised reward’, rewards of requital are distributed when ‘the action is done solely from a good disposition, from pure morality’ (L-E/Kaehler, 80; see also Schmucker 1961: 356). Actions ‘done merely out of a good disposition and pure morality are eligible for the praemiorum remunerantium … for here the action accords with morality and that is the greatest worthiness of happiness’ (L-E/Kaehler, 81; see also A810/B838; CPrR, 5: 130). Hence, ‘the morally disposed person is eligible for an infinite reward and happiness’ and ‘can expect the reward from the supreme being’ (L-E/Kaehler, 81). These ‘praemia moralia’ follow from consciousness of the moral law in the morally upright: ‘the natural moral law already carries such promises with it in a subject that has a morally good disposition’ (p. 82).

The prospect of happiness in proportion to worthiness of it, entailed by consciousness of the moral law, implicates the idea of God. Recall Kant’s claim, suggestive of eudaimonism, that ‘without a supreme judge all moral laws would be without effect, for in that case there would be no incentive, no reward, and no punishment’, from which he concludes that ‘cognizance of God is necessary with respect to the execution of moral laws’ (L-E/Kaehler, 62). The efficacy of morals laws, then, turns on God’s role as supreme judge. Kant’s remarks on the role of a judge elsewhere in the lectures are instructive: ‘he who is warranted to adjudicate with legal effect and also has authority to carry it out is a judge’ (p. 100). God, as supreme judge, is authorised to bestow happiness upon those who are worthy of it. As explained in the second Critique, this presupposes God’s moral perfection and omnipotence: ‘only from a will that is morally perfect (holy and beneficent) and at the same time also all-powerful … can we hope to attain the highest good’ (CPrR, 5: 100; see also L-E/Kaehler, 117). In the 1770s lectures on ethics, the representation of God’s moral perfection is a consequence of consciousness of the moral law: ‘hence we recognize the divine will through reason; we represent God as having the most holy and most perfect will … thus we recognize the perfection of the divine will from the moral law’ (L-E/Kaehler, 100).

God’s moral perfection qualifies him as lawgiver, who ‘declares that the necessary practical laws accord with his will’ (L-E/Kaehler, 79). ²⁶ Note, however, that God is not the ‘author’ of the moral law, since it is necessary in itself; ‘nevertheless, moral laws can still be subject to a lawgiver, [i.e.,] there may be a being who has all power and authority to execute these laws and to declare that this moral law is simultaneously a law of his will and obligate everyone to act accordingly’ (p. 79; see also MM, 6: 227). ²⁷ As morally perfect, God’s will is ipso facto in conformity with the moral law. This, coupled with his moral perfection and omnipotence, qualifies God to declare moral laws to be also laws of his will. By conceiving of moral laws as divine commands, we satisfy the condition – presupposed by the highest good – that our moral volition harmonise with the will of a supreme being alone capable of connecting happiness with moral worth: ‘thus, God must necessarily reward human beings whose conduct conforms to moral laws … for [in this case] human conduct harmonizes with the moral laws and therefore with the divine will as well’ (L-E/Kaehler, 46). ²⁸

Even if all this is correct, what are we to make of Kant’s suggestion that without God, ‘all moral laws would be without effect, for in that case there would be no incentive’ (L-E/Kaehler, 62)? Kant’s point, I take it, is that the denial of a condition of the highest good would undermine moral efficacy. ²⁹ Since the highest good is a corollary of the moral law, to abrogate the possibility of the highest good would commit us to a contradiction in our practical rationality. ³⁰ Consequently, the moral law would lose its incentive force.

This view is reflected in Kant’s conception of postulates at the time. Thus, in a Reflexion from the mid-1770s, Kant characterises a postulate as ‘a theoretical hypothesis necessary in a practical respect, such as those of the existence of God, of freedom, and of another world. The practical propositions are objectively certain; subjectively, they can be practical only insofar as such hypotheses underlie them’ (R 3133, 16: 673). In another Reflexion from the same period, Kant claims that a presupposition is a ‘postulate’ if the ‘propositions on account of which the presupposition is made are a priori necessary, e.g., moral propositions and their motive force. Hence the presupposition of God is a postulate for the purpose of morality’ (R 5624, 18: 260). So, the existence of God does not provide an incentive for moral agency but is postulated by pure reason as a consequence of our recognition of the highest good as a corollary of the moral law. This postulate safeguards the pure moral incentive from losing its practical efficacy.

As is generally recognised, Kant’s later works imply his sustained commitment to this view. ³¹ Thus, in What Does it Mean to Orient Oneself in Thinking?, Kant argues that reason must assume a supreme intelligence for the sake of the highest good, ‘not of course, to derive from this assumption the binding authority of moral precepts or the incentives to observe them (for they would have no moral worth if their motive were derived from anything but the law alone, which is itself apodictically certain)’. Instead, this assumption serves ‘to give objective reality to the concept of the highest good, i.e., to prevent it, along with morality, from being taken as a mere ideal, as it would be if that whose idea inseparably accompanies morality should not exist anywhere’ (WOT, 8: 139). Similarly, in the Critique of Practical Reason, he claims: ‘since the promotion of the highest good … is an a priori necessary object of our will and inseparably bound up with the moral law, the impossibility of the first must also prove the falsity of the second’. Consequently, ‘if the highest good is impossible in accordance with practical rules, then the moral law, which commands us to promote it, must be fantastic and directed to empty imaginary ends, and must therefore in itself be false’ (CPrR, 5: 114; cf. 5: 143). Likewise, in the Critique of the Power of Judgement, Kant asserts that if the highest good were impossible, then reason ‘would regard the moral law itself as a mere deception’ (CPJ, 5: 471n). ³² So, Kant’s 1770s position on the relation between moral efficacy and the highest good reflects his considered view on the topic throughout his mature corpus.

5. Conclusion

I have argued that Kant’s 1770s view on moral motivation entails that the moral incentive is effected by consciousness of the moral law. So, pure reason is practical. However, on the reading I have offered, our capacity to be affected by moral judgement requires empirical cultivation in order for the moral law to be practically efficacious. Furthermore, the postulation of God’s existence as a condition of the highest good is necessary to moral agency. By way of conclusion, I indicate two payoffs of my interpretation: first, it provides a key for understanding Kant’s apparently quasi-eudaimonistic claims in the Critique of Pure Reason; second, it shows that Kant developed the core features of his account of autonomy nearly a decade earlier than generally thought.

In the first Critique, Kant assumes ‘pure moral laws which determine completely a priori … the use of the freedom of a rational being’ and which ‘command absolutely’ (A807/B835). However, he supposedly endorses a quasi-eudaimonist conception of moral motivation by citing ‘worthiness to be happy’ as the ‘motive’ of the moral law (A806/B834; see also Allison 1990: 67, 2020: 297; Pasternack 2013: 43ff.; Walschots 2022: 247). Moreover, God is said to endow the moral law with obligatory force by virtue of this prospect: without a ‘supreme being’ obligation ‘would be without any incentives’ (A589/B617); hence, moral laws ‘presuppose the existence of a supreme being’ for their ‘obligatory force’ (A634/B662; see also Timmermann 2019: 115). With the results of Section 4 in view, however, it becomes clear that Kant neither considers the hope for happiness in proportion to worthiness of it to be the moral incentive, nor appeals to God as the source of the obligatory force of the moral law. ³³ Instead, worthiness to be happy partly constitutes the highest good, the prospect of which is not an incentive but a necessary idea connected with morality: ‘the moral disposition, as a condition, first makes partaking in happiness possible, rather than the prospect of happiness first making possible the moral condition’ (A813/B841). As in the 1770s lectures on ethics, we are ‘internally obligated’ by laws with ‘inner practical necessity’ (A818-19/B846-7; see also L-E/Kaehler, 27, 37–8). Likewise featured in the 1770s lectures, the connection between God and the obligatory force of moral laws is a consequence of the highest good: thus, reason must assume the conditions of the highest good ‘or else regard moral laws as empty figments of the brain, since without that presupposition their necessary consequence, which the same reason connects with them, would have to disappear’ (A811/B839). So, moral laws do not first become obligatory through the idea of God; rather, we must postulate the existence of God so as not to undermine their intrinsic obligatory force.

Despite the fact that the term ‘autonomy’ never appears in the 1770s lectures on ethics, I submit that Kant’s account of autonomy was already in place at this time. Autonomy is the ‘property of the will by which it is a law unto itself’ (G, 4: 440). For Kant, the sole law fit to hold this office is a universal, intrinsically binding one whose seat is in pure reason. Kant is generally taken to have developed his conception of autonomy in 1784–5 (e.g., Reath 2019; Sensen 2019; Timmermann 2019), as evinced by his treatment of it in the 1784 Feyerabend lecture notes on natural right. ³⁴ Moreover, scholars argue that autonomy includes a motivational element (Allison 2013: 131; Korsgaard 1998: xxi, xxivff.), which was supposedly lacking until Kant’s development of respect for the moral law around the same time (Chance and Pasternack 2018: 197; Pasternack 2013: 44; Reath 2019: 193–4; Sensen 2015: 192ff., 2019: 97ff.). As I have argued, the intrinsically motivating character of the moral law was already in place in the mid-1770s. Coupled with the moral law’s universal form (L-E/Kaehler, 64ff.), its internal obligatory force (pp. 37–8, 80), and its source in pure reason (pp. 26–7, 60), Kant’s 1770s view on moral motivation demonstrates his commitment to the will’s property of being a law unto itself.