I. Common Rational Capacities

The aim of Kant’s practical philosophy is not to construe a moral philosophy from scratch, but to make intelligible and to vindicate our ordinary understanding of morality.Footnote ³ In her moral reasoning, the common agent, even without any philosophical background, ‘stands as good a chance of hitting the mark as a philosopher can ever expect; indeed is almost more sure in this than even the latter’ (IV:404.23-25). Kant’s practical philosophy rests on the assumption that the common agent is a fully functioning moral agent. The competence of the common agent even leads Kant to wonder whether or not practical philosophy is necessary at all (IV:404.28-30, V:36.7-8).Footnote ⁴

In the preface to the Groundwork, Kant explains that his method will be to start with common cognition, determine and examine its principle, as well as the sources of this principle, and take the route ‘back to common cognition, in which we find it used’ (IV:392.21-2).Footnote ⁵ The title of the first section of the Groundwork announces a transition from our common moral rational cognition to philosophical cognition.Footnote ⁶ The supposedly common notion of the unconditional value of the good will, as well as the verdicts of common rational capacities regarding exemplary cases, discussed in this first section, serve as a starting point for Kant’s enquiry (see also XX:340.26-341.6).

Kant begins the Groundwork’s first section with his famous claim that it is not even possible to think of something to be unconditionally good except a good will.Footnote ⁷ If not every single agent, then at least ‘common reason’ is in ‘agreement’ (IV:394.32-6) with Kant’s take on the unconditional goodness of the good will, Kant believes. Kant does not take his assumption about moral goodness to be a philosophical invention, but an explication of what the common agent is already committed to in her reasoning about morality: Moral commands are unconditionally valid. The moral law has a firm grip on the agent, and the agent is aware of this. For common agents practical cognition ‘comes together with unconditional bindingness’, or with the consciousness of absolute authority (see VI:181.33-4, VI:481.31-6).Footnote ⁸

Not only does the common agent understand that morality comes with a special normative force that is not based on anything contingent. She is, according to Kant, also able to employ universality, a rational criterion, in her ordinary reasoning about what ought to be done in a concrete situation (IV:402.7-13). Kant presents the universalisation test, which is given an abstract and universal formula by the Universal Law Formulation of the Categorical Imperative, as what common agents ‘always actually have before their eyes and use as the standard of judging’ (IV:403.36-7). In morally relevant situations the common agent can apply her insight into the significance of universality by asking herself ‘would I actually be content that my maxim […] should hold as a universal law’ (IV:403.5-8)?Footnote ⁹

Common rational capacities function as a pre-philosophical ‘standard’ (IV:403.37, see also V:155.13-9). They reliably guide reasoning about morally relevant cases. The common agent, however, lacks ‘insight’ (IV:403.27) into the underlying structure of her judgements and reasoning. The insights afforded by common rational capacities are unreflective (VII:58.18-30), ‘obscure’ (IV:450.37-451.1, V:228.18-20, 238.6-11, VI:216.32-3, 376.25-6, XX:226.16-31), or appear as a mere feeling, not as a rational and necessary cognition to her (IV:451.1), and manifest themselves only in reasoning about concrete cases.Footnote ¹⁰ Common agents lack an explanation for why their judgements about concrete cases are correct, and they lack a reflected defence of their way of reasoning. It is the philosopher’s task to ‘bring to light’ (IV:397.3) or ‘develop’ (ibid. 6) what is already present in the common use of reason, and make the common agent aware of or attentive to her own principle (see also VI:183.20).

The common agent’s rational and moral abilities and insights raise the question as to why a philosophical systematization and vindication of the common way of reasoning is useful at all. This question is answered in the penultimate paragraph of Groundwork I (IV:404.1-405.19). The common agent is caught in a ‘natural dialectic’ (IV:405.13). The dialectic is not something accidental, but due to the double nature of finite rational agents, i.e., due to the tension between unrelenting moral commands rooted in finite agents’ rational nature and their natural desire for happiness rooted in their sensuous nature.Footnote ¹¹ The common agent is in a state of ‘fortunate simplicity’ (IV:404.34), since she has a conception of goodness that is not skewed by ‘alien and irrelevant considerations’ that confuse and deflect the evaluations of the philosopher (IV:404.25-28). However, without a justification that enables to defend her practical cognitions, an agent is ‘easily seduced’ (IV:405.1). Seduction is a temptation with a cognitive component, namely with a story of why it would be permissible in a certain situation to give in to sensuous incentives.

When an agent gives in to temptations she begins to ‘rationalize’ [vernünfteln] (IV:405.14): to cast doubt on some features that are, according to Kant, essential for a correct conception of the morally good, namely ‘strictness’ and ‘purity’ of the moral law, and maybe even on its ‘validity’ (IV:405.14-5). Rationalizing means inventing seemingly compelling but normatively ungrounded stories, supposed to justify exceptions to the moral law, and to ‘transform’ (IV:424.31) one’s awareness of what ought to be done into a conception that is more lenient and allows more room for our ‘dear self’ (IV:407.25-6). Rationalizing is a process that unfolds within common reason itself. An agent adapts her conception of morality to her desires, and this ‘corrupts’ (IV:405.17) a common agent’s conception of the good, and ultimately her character, since an agent who is caught in the web of her rationalizations does not put duty first. On the contrary, she has conditioned obedience to the moral law on exceptions and qualifications.

The danger of corruption impels the common agent ‘to seek help in philosophy’ (IV:405.32-3). Practical Philosophy can make agents attentive to their own principle (see IV:404.5) by identifying the principle that underlies the moral appraisals of the common agent, and by giving it an abstract, and universal formulation. This happens in Groundwork II. From practical philosophy the common agent can also receive ‘intelligence and distinct instruction regarding the source of this principle’ (IV:405.23-27, my emph.). This is the task of Groundwork III. Practical philosophy as Kant advocates it proceeds in three steps: It identifies what the common agent is committed to when she reasons about concrete cases; it systematizes the concepts and principles identified in this reasoning, and spells out their implications and relations to each other in the form of a theory; it vindicates this theory by showing that the theory has a rational source.Footnote ¹² Kant hopes that uncovering the source of morality and showing that rational agents in their ordinary reasoning are already committed to the proposed grounding of morality, can serve as a protection and ‘antidote’ (Wood Reference Wood2002: 28) against the corrupting influence of rationalizing.Footnote ¹³

A pure practical philosophy, which can provide this protection and antidote, is ‘a desideratum of the highest importance’ (IV:410.24). To establish such a practical philosophy, Kant in Groundwork II first surveys and criticises popular philosophical approaches to moral goodness as inadequate responses to the natural dialectic. He shows that the common agent’s moral evaluations are not arbitrary, but guided by a rational principle that finds its philosophical formulation in the various Categorical Imperative formulae. Whilst the first two Groundwork sections presuppose the correctness of the common way of reasoning (Groundwork I), or the validity of the underlying abstract and universal principle (Groundwork II), and aim to ‘identify’ the supreme principle of morality, Groundwork IIII aims to ‘corroborate’ or vindicate this principle (IV:392.4), or to show that it is unconditionally binding for creatures like us (see IV:440.20-32, 447.8-14).

Common rational capacities are important for the Groundwork on the level of assessment of single cases, formulation of moral principles that underlie this assessment, and justification of these principles. They are most important on the first of these levels, since there they generate or deliver material for philosophical systematization. On the second level they merely ‘agree’ that there must be a formal law as a principle for the will, ‘if duty is not to be as such an empty delusion and chimerical concept’ (IV:402.12-3), and Kant’s entire conception a mere ‘phantasm’ (IV:445.9). On the third level they confirm the metaphysical case Kant makes for his conception. Kant wants to emphasize that even in his most abstract conceptions and operations, which can only be the result of philosophical reflection, he does not leave behind what common agents are already committed to insofar as they reason about certain moral subject-matters in an ordinary way.Footnote ¹⁴

Confirming the correctness of a complex philosophical operation cannot mean that the common agent on her own can perform the deduction, or that the deduction will be easy for her to understand. After all, controversies in the Kant literature concerning many aspects of the deduction show that the deduction is, if at all, not easy to grasp even for philosophically trained readers. It is the ‘correctness’ (IV:454.21) of the deduction that is confirmed, not the entire operation. Confirming the correctness, presumably, means that the result or conclusion of the philosophical operation is not alien to a common agent. The deduction spells out and at the same time grounds important elements of the self-understanding of the common agent and it does it in such a way that the common agent can still recognize these elements in the philosophical argument.

II. Common Rational Capacities and the Deduction

The aim of Kant’s deduction is controversial; it is not entirely clear whom Kant wishes to address, or convince, and what Kant takes to be the burden of proof on him when engaging his intended audience. Kant explicitly says that the aim of the deduction is to show ‘whence the moral law is binding’ (IV:450.16), i.e., where the special status of morality comes from, or what its source is: Prudence, divine command, reason, etc.? Already in Groundwork II when discussing the differences between hypothetical and categorical imperatives, Kant foreshadows that the aim of the deduction cannot be to discuss whether the Categorical Imperative is binding. The ‘only’ question that stands in need of a solution is ‘how the imperative of morality is possible’ (IV:419.12-3, my emph., see also IV:420.21). The explanation of how Categorical Imperatives are possible is supposed to make clear that it is not the case that Categorical Imperatives are hypothetical (IV:419.15-9), as someone who buys into a mistaken conception of the source of morality might suspect.Footnote ¹⁵ If Kant wishes to address a sceptic in Groundwork III, it is a sceptic of a particular kind, namely one who accepts moral commands, but believes that they have to be obeyed for reasons of prudence or self-interest. It seems questionable whether we would call this person a ‘sceptic’, since she agrees with the Kantian philosopher concerning the question as to which actions ought to be performed or omitted. At most she is a sceptic concerning the source of morality.Footnote ¹⁶

The task of the deduction is of an explanatory nature: The common agent already recognises the moral law as authoritative (see section I), but she might wonder what the foundation of the special status of the moral law is, and how it is possible that she, as a creature who vividly experiences the force of sensuous needs and inclinations, is under moral obligations. This task requires an inquiry into the source and metaphysical background of our ordinary understanding of morality, or into what we are committed to insofar as we pre-theoretically reason about morality. It is important to note that one can have a commitment without being aware of this. When I believe ‘A implies B’ and ‘A’, I am committed to ‘B’, though as a matter of fact I might not believe ‘B’ (not even implicitly). In fact, I might even believe ‘not-B’. Once my beliefs in ‘A’ and ‘A implies B’ are clearly presented to me, I will see that ‘B’ is a coherent, and even necessary part of my system of beliefs and assent to ‘B’ (or alternatively revise my belief in ‘A implies B’, ‘A’, or, most drastically, in the validity of modus ponens).

The deduction can be understood as spelling out the ultimate commitment of what the common agent is doing, when she engages in rationalFootnote ¹⁷ deliberation: reasoning from a rational or intelligible point of view. In what follows, I will show that the common agent can be content with the result of the complicated philosophical deduction, since the deduction draws on the notion of a special, intelligible standpoint that the common agent is disposed to accept, since the possibility, actuality, and supreme value of this special standpoint can be traced back to the way she reasons about the world, herself and morality.

In the first sub-section of Groundwork III, Kant starts his argument with the notion of freedom as the ‘key to the explanation of autonomy’ (IV:446.6). He introduces what is sometimes called the ‘Reciprocity Thesis’: the claim that freedom and the moral law are reciprocal concepts.Footnote ¹⁸ In the second sub-section, he argues that freedom needs to be presupposed as a property of the will of all rational beings, and that morality ‘must be derived solely from the property of freedom’ (IV:447.32-3).

These two sub-sections have already on their own ignited much debate in the literature.Footnote ¹⁹ I cannot say more about them here, and will begin my discussion with Kant’s worry that his argument from freedom to morality might be circular: We ‘take ourselves as free in the order of efficient causes in order to think ourselves under moral laws in the order of ends’ and ‘afterwards think ourselves as subject to these laws, because we have already ascribed to ourselves freedom of the will’ (IV:450.19-23). We can phrase this circle as follows: Why do we consider ourselves free? Because we think of ourselves as subject to moral laws. Why do we think we are subject to moral laws? Because we attribute to ourselves a free will.Footnote ²⁰

According to Sussman (Reference Sussman2008: sec.1-3), Kant does not worry about a possible logical blunder in his argument, but rather that his argument in the first two sub-sections might only show that morality can motivate free agents, but not that its normative force always trumps inclinations. Something other than a logical fallacy might be the issue in the first sub-sections, and hence what is to be expected is not so much a simple disambiguation of terms, which would resolve a circle, but something that furthers Kant’s argument in a different way. We will come back to this idea when discussing the scoundrel below.

Kant declares that the suspicion of circularity is ‘removed’ (IV:453.3) by the notion of two different ‘standpoints’ (IV:452.25-6) that an agent can take up. She can consider herself from an empirical standpoint as a member of the sensuous world, in which she is subject to laws of nature. She can also consider herself from an intelligible standpoint as a member of the world of understanding, in which she is subject to laws of reason (IV:452.26-30).Footnote ²¹ Transferring oneself in thought into the world of understanding helps to become aware that one is an autonomous agent. Insofar as we conceive of ourselves as obligated by moral commands we think of ourselves as part of both, the sensuous and the world of understanding (IV:453.3-15).

It seems that the discussion that leads to the alleged circle, instead of being Kant’s main argument that still stands in need of some terminological disambiguation, is rather supposed to merely set the stage for Kant’s introduction of the different standpoints. As a result of the introduction of the two standpoints, Kant takes himself to have established that finite agents acknowledge that they are under moral obligation, and he takes himself to have provided a rationale or source for this, namely, our membership in the two worlds, and particularly in the world of understanding. Providing this rationale or explaining where our obligation comes from is the aim of the deduction. By understanding that she is a member of both worlds, an agent understands that there is a law different from the laws of the sensuous world. This, however, only gives us the moral law, the law of this other world, not the Categorical Imperative, which is the moral law plus unconditional authority. Kant needs to establish that the law of this other world ought to govern the actions of finite rational agents unconditionally.

Kant assumes that the world of understanding contains ‘the ground of the world of senses, and hence also its laws’ (IV:453.32).Footnote ²² The, at best, ‘sketchy’ (Timmermann Reference Timmermann2007: 140) argument that Kant gives for the priority of the intelligible is, in short, that the world of understanding can necessitate agents, whereas the sensuous world cannot. The laws of the world of understanding are represented by the agent as unconditionally necessary and demand strict and exceptionless obedience, whereas the laws of the sensuous world are cognized without normative authority.Footnote ²³ There would be no reason not to break laws of nature, if we could break them, whereas a violation of the Categorical Imperative is followed by feelings of guilt, remorse, pangs of conscience, etc., because agents commonly think of moral laws as something normative that cannot be transgressed merely because one has an inclination to do something that can only be done by transgressing these laws. If agents could break laws of their sensuous nature, they would not experience a similar pressure to excuse or seemingly justify their doing.Footnote ²⁴ Kant later provides a related argument, when he calls an agent’s rational self her ‘proper’ self (IV:457.34, 458.2, 461.4), indicating that there are certain ontological reasons, or perhaps reasons based on a certain kind of authenticity, to follow intelligible laws.Footnote ²⁵

Considering oneself from an intelligible standpoint is of pivotal importance in explaining how the moral law obligates an agent. The contribution of common rational capacities to the deduction is to show that the intelligible standpoint is not simply the standpoint of the philosopher, but rather a standpoint available to every rational agent, and that the common agent accords a higher status or value to the world of understanding. Kant provides three considerations intended to show he is drawing on commitments of common agents. The first draws on theoretical insights of the common agent (1), the second and third refer to the practical (2) and moral (3) understanding of the common agent.Footnote ²⁶

(1): In a digression, Kant claims that even ‘the commonest understanding’ (IV:450.36-7), without ‘subtle thinking’ (IV:450.35-6) is aware through ‘an obscure distinction of the power of judgement, which it calls feeling’ (IV:450.37-451.1)Footnote ²⁷ that we, as finite human beings, can only cognize appearances, never things as they are in themselves (IV:451.1-8). As a result we assume behind the appearances something that is not appearance, namely things in themselves or a world of understanding (IV:451.8-24). That an agent can have no experience of the world of understanding holds even for the intelligible part of that agent herself (IV:451.31, B:157-9). The agent is, however, aware that part of herself belongs to the world of understanding (IV:452.23-30).

Kant stresses that the inferences drawn from the obscure insights into the possibility of a world beyond experience are ‘presumably also to be found in the commonest understanding’ (IV:452.1-2). Common understanding, however, ‘spoils’ (IV:452.4) its insights by treating the world of understanding as if it were simply another, albeit epistemically removed, sensuous world. According to the common agent, the reason why there are entities that are ‘completely unknown’ (A/B:42/59, see also A/B:494/522-3), is that these entities cannot be experienced for contingent reasons (they might be too far away, too small, etc.) (IV:452.4-6).

Kant here attributes insights to common rational capacities that, according to some interpreters, amount to ‘an argument for transcendental idealism from the material available to ordinary reason’ (Tenenbaum Reference Tenenbaum2012: 582). Not only is a common agent aware of the limitation of her finite capacities to cognize the world, she also has some grasp of the implications of these limitations: She understands that it is possible that there are things or a ‘world’ of things that she cannot cognize. The common agent, however, lacks a firm grasp of how fundamentally different this ‘world’ is, and does not understand that finite agents, in principle, cannot cognize the world of understanding.

There are many thorny issues pertaining to Kant’s distinction between the sensuous and the intelligible. The most prominent of these is the question as to whether this distinction is one between different worlds, or between different aspects of the same world.Footnote ²⁸ Kant points out that the distinction he makes in Groundwork III is ‘rough’ [roh] (IV:451.18), and later adds the caveat that the distinction serves practical purposes only (IV:457.4-459.31). In Groundwork 450-2, Kant does not intend to elaborate on his conception of transcendental idealism. His aim is to describe how the common agent tries to make sense of her insight that her rational or cognitive capacities are finite, or that her experiences have limits.Footnote ²⁹ The common agent is aware that the sensuous world cannot be all there is, and that there has to be a world removed from the causal order of experience. Viewing the world and oneself from the perspective of such a non-causal world means taking up the intelligible standpoint.Footnote ³⁰

(2): Kant’s considerations in (1) only show that the common agent can envisage the possibility of another than the empirical standpoint. Kant also thinks that the intelligible standpoint is, at least implicitly, often frequented by common agents.

Kant believes that ‘all human beings think of themselves as having a will that is free’ (IV:455.11), and that this presupposition is necessary for every rational being.Footnote ³¹ Having to act under the idea of freedom is equivalent to freedom ‘in a practical respect’ (IV:448.6). Kant maintains throughout his critical writings that common agents do not understand the foundation of freedom, or how freedom is possible (IV:456.8-9, 458.36-459.31), and that from a theoretical perspective we cannot be certain that we are free, and that the foundation of freedom is ‘inscrutable’ [unerforschlich] (VI:138.19), and ‘not given to us for cognition’ (VI:138.20). Nonetheless, the conviction that we are free will never be ‘wrested’ (V:134.2) from ‘even the most common human being’ (V:134.1-2). Kant even attributes to a newborn child ‘an obscure idea […] of freedom’ (VII:269fn.).

There is much debate about how to understand Kant’s ‘bald assertion’ (Allison Reference Allison2012: 113) that we necessarily have to act under the idea of freedom, and that this is more than a heuristic fiction or an illusion of freedom. Kant is trying to articulate the insight that, no matter what the natural sciences discover and teach about the world, rational agents necessarily have the impression that they are not (always) compelled by their desires, but can reflect about desires, and rationally deliberate about their options.Footnote ³²

Agents, insofar as they act, i.e., do something as the result of rational deliberation, are committed to the notion that they are free, or they have to assume this, and they can, upon reflection, become aware of their freedom. Jeanine Grenberg (Reference Grenberg2009: 341; 2013: ch.5) argues that ‘freedom’ in Groundwork III should be understood not in a morally qualified sense, but as ‘negative freedom’ with a ‘slight movement beyond negative freedom’ (Grenberg Reference Grenberg2009: 349). What Grenberg has in mind is the everyday experience of acting without coercion and bringing about consequences in the external world that we can recognize as the consequences of our doing, and that make us aware of our freedom (ibid. 340-1).Footnote ³³ Such a deflationary account of freedom as (mainly) negative makes plausible Kant’s claim that agents who deliberate about their actions are committed to being free and can become aware of their freedom. After all, deliberating only has a point when we assume that we are in principle able to bring about consequences as a result of our decisions. Kant’s claim that we must necessarily act under the idea of freedom is certainly more contentious if we assume a morally loaded conception of freedom.Footnote ³⁴

Awareness of their freedom transfers agents into the rational order of things; an order they, as a result of understanding of the limitations of their cognitive capacities, deem to be possible. Through their awareness of freedom, common agents understand that different laws apply to them insofar as they transcend the causal order of things. The deduction, in so far as it draws on the special point of view of free agents, appears to these agents as a natural extension of this standpoint. The intelligible standpoint is the standpoint that common agents take to be their standpoint insofar as they are aware that they are free (IV:455.1-4). Without an agent’s capacity to become aware of her freedom, the deduction would be utterly unconvincing for this agent, since the deduction would seem to her like a manoeuvre drawing on the commitments of a metaphysically different kind of being.

(3): After his deductionFootnote ³⁵, Kant provides his most explicit illustration of how ‘the practical use of common human reason’ (IV:454.20) confirms the correctness of the deduction. Even the ‘most hardened scoundrel’ (IV:454.21), an agent in the grip of inclinations but nonetheless rational, is, according to Kant, still able to recognise ‘examples of probity of purpose, of steadfastness in following good maxims, of compassion and of general benevolence’ (IV:454.23-25), and to acknowledge the ‘repute’ (IV:455.6) of the moral law, i.e., that the moral law imposes obligations on him.

The examples of moral conduct necessitate the scoundrel to ‘transfer himself in thought in an order of things quite different’ (IV:454.31-2): the world of understanding. As a member of the world of understanding the scoundrel is aware of his ability to be guided by a law of reason, which ‘by his own admission’ (IV:455.5-6) constitutes the law of his will. The sensuous scoundrel might rebel against the commands of morality, the rational scoundrel, by contrast, experiences morality as his ‘own necessary willing’ (IV:455.7). The scoundrel, when presented with examples of outstanding moral conduct, wishes that he might be ‘disposed’ (IV:454.27) like the person in the examples. Kant’s idea is that a rational agent can be brought to acknowledge the authority of the intelligible standpoint via examples of conduct that demonstrate that creatures like the agent, and indeed he himself, are able to deliberate and to act from the rational standpoint.

Even commentators who are generally sympathetic to Kant, such as Henry Allison, charge the scoundrel case with psychological implausibility. Kant assumes that upon encountering examples of morally good conduct, the idea of freedom ‘without his choosing necessitates’ (IV:455.3-4) the scoundrel to view himself as part of the world of understanding, and that it is not possible for the scoundrel to simply ‘scuff off the manifestation of goodness’ (Allison Reference Allison2011: 342). One important factor that bears on the plausibility of the scoundrel case is what it means for the scoundrel to be ‘otherwise in the habit of using reason’ (IV:454.22). It certainly means that the scoundrel is endowed with instrumental rationality. The scoundrel is also, at least potentially, still capable of moral deliberation. After all, ‘scoundrel’ is an evaluative term that shows that Kant thinks the scoundrel can be subject to moral criticism.Footnote ³⁶

The scoundrel is an agent who fails to do what he is, in some sense, aware of as obligatory, and who feels justified in doing so, because his insight into what ought to be done has lost clarity and salience. The scoundrel, admittedly, cannot be entirely corrupted. He might not be able to give the right answers to morally relevant questions right away, but he at least has the ability to recognize morally worthy conduct when it is pointed out to him. The insights of his common rational capacities are not entirely lost, but clouded, or eclipsed by rationalizing (see section I). The scoundrel is confused about morality, in the sense that he does not think thoroughly enough about morally relevant subject-matters to fully appreciate the majesty of the moral law. He has a story that he tells himself to justify his conduct to himself.

The scoundrel’s change of attitude becomes more psychologically plausible when we take Kant’s claim that we have to present ‘examples’ (plural!) (IV:454.23) seriously. Kant does not believe that presenting a single case of morally good conduct is sufficient. Dealing with the scoundrel might be pulling teeth. We have to present numerous and various examples, engage the scoundrel in dialogue, explain certain background assumptions, etc. Kant appeals to Socrates (IV:404.4) as a methodological paradigm of philosophy and moral education, because Kant is aware that sometimes a dialogue or critical exchange, and even showing that certain convictions are unfounded and lead into an aporia, are required to set corrupted agents right.

Kant does not assume that the scoundrel can change his disposition ‘easily’ (IV:454.28)Footnote ³⁷, but only that, after hard work, the scoundrel can be brought to acknowledge that he is subject to the laws of the rational order of things. In addition, Kant stresses that the scoundrel’s acknowledgement of the repute of the moral law occurs as the scoundrel ‘transgresses’ (IV:455.6-7) this law. The scoundrel does not change his behaviour, but only becomes aware that he does not live up to the standards of his rational self, and that the perspective he takes up when he makes use of his rational capacities enjoys normative priority over his sensuous self.

Kant’s assumption is that an agent endowed with common rational capacities always has, at least with the help of a philosopher or educator, enough rationality left to take up the rational point of view, and to acknowledge that this standpoint is normative and higher than the sensuous standpoint and the needs and inclinations that come with it. The worry with this assumption is, I think, not so much its psychological plausibility but rather the question as to whether this is sufficient to establish what Kant wishes to show, namely that the law of reason is not merely normative, or of greater importance than inclination, but that it is unconditionally binding, and can never be outweighed or overwritten by inclinations or the enticing appeal of happiness. This is a version of the worry that Sussman sees at the bottom of what Kant thinks is the circularity problem: Morality might be normative, but its normative force might fail to always trump inclinations. As I see it, nothing in the scoundrel case shows that the scoundrel acknowledges more than the ‘greater inner worth’ (IV:454.37) of his rational self. This is, however, very different from the unconditional worth of morality. The scoundrel case is only a partial confirmation of Kant’s deduction.Footnote ³⁸

Kant’s discussion of rationalizing at the end of Groundwork I as something that hinders or perverts moral cognition suggests that Kant’s goal is to help common agents gain a better understanding of the source of morality. This is certainly the case, but the scoundrel case also shows that Kant does not detach questions of motivation from this better understanding. The scoundrel does not merely understand that his behavior was and is wrong, but also wishes that he could act differently (though this wish might still be too weak a motive to actually move him to moral actions).Footnote ³⁹ Kant believes that the membership in a world of understanding, which philosophy can make an agent aware of, affects the agent’s motivation and can be a tool for moral improvement.

III. The point of having the Common Agent on one’s side

The confirmation of the deduction by common rational capacities shows that Kant, in the Groundwork, does make his way from judgements of common agents about concrete cases of moral relevance back to the commitments of common agents. He begins with common propositions about morality, and the way in which common agents reason about morally relevant cases, and he concludes his argument with the scoundrel, an agent who confirms one of the central elements of his deduction, because he has enough reason left to acknowledge the repute of morality.Footnote ⁴⁰ The confirmation of the deduction by common rational capacities shows that Kant’s complex philosophical operation can become popular. It is, in principle, accessible to the common agent, or can be communicated to this agent in a way that she can understand, because the deduction spells out some of her fundamental commitments regarding the limits of her cognitive abilities, and her awareness of freedom and morality.

The structure and aim of the Groundwork suggest that the confirmation of the common agent is not a manoeuvre to gain additional philosophical credibility in debates with academic colleagues. Kant must have been aware that it would be anything but easy to convince his colleagues that the common agent, or what he takes to be the common agent, is more trustworthy and delivers better material and confirmation for moral philosophy than the views of professional ethicists. The deduction is supposed to address the worry raised at the end of Groundwork I: The common agent stands in need of a clarification, systematization, and vindication of her judgements, and their underlying assumptions, in particular in need of a better understanding of the source of morality, since everything else hinges on this source. An agent who wants or needs more than an abstract principle and a systematization of concepts, because she is seriously confused about the morally good, or simply persistent in her critical questions, can only be helped by the content of Groundwork III.

The deduction serves a practical purpose. It is supposed to uncover means to address forms of corruption that can arise as a result of rationalizing, namely attempts to conceive of the moral law as admitting of (occasional) exceptions, or that moral commands might not be unconditionally binding, but can be outweighed by expected consequences of actions, or by the impact an action would have on an agent’s life and happiness.Footnote ⁴¹ Kant thinks that these challenges can be addressed by showing that our ordinary notion of obligation is founded on reason or on membership in a world of understanding (and hence is universal in scope, does not admit of exceptions and cannot be rationally outweighed), and he thinks that this response has to be given in such a way that not only people with a background in philosophy can benefit from it.

Kant is fully aware that it is unrealistic to assume that many common agents will work through Groundwork III. Practical philosophy is, according to Kant, not supposed to be immediately action guiding. Instead, philosophy is supposed to establish a ‘doctrine of wisdom’ (V:163.28), and this doctrine can ‘serve teachers as a guideline to prepare well and clearly the path to wisdom which everyone should travel, and to secure others against taking the wrong way’ (V:163.29-31). The function of practical philosophy in the Groundwork and the Second Critique is to inform popular philosophers and educators, and thereby to indirectly influence the moral education of people who lack a philosophical background. Only philosophy in whose ‘subtle investigations’ the public has to take no interest, can present a doctrine of wisdom with sufficient clarity regarding the formulation, source, and bindingness of a supreme principle of morality to facilitate a moral education that is sufficiently clear, rigorous and theoretically grounded (V:163.33-35). Practical philosophy has to determine the guidelines of moral education by uncovering our common conception of morality, and by showing how this conception can be grounded and defended.Footnote ⁴²

The confirmation of common rational capacities does not establish that there cannot be a more sophisticated, or better founded account of the supreme principle of morality or of its source. It is supposed to show that even the most abstract part of the Groundwork still can serve Kant’s overall project to vindicate the common perspective in a way that can be of practical use or that can be relevant for everyone. The confirmation of the deduction can be understood as Kant’s response to what Nietzsche calls ‘Kant’s Joke’:

It is true that Kant wrote for scholars, but he was convinced that scholars could translate his defence of the common agent into a language that would not dumbfound, but protect and better the people.

This optimism is a second sense in which Kant makes his way from the common cognition of duty back to the common cognition. His philosophical investigation and vindication of the common cognition has the potential to positively affect the common cognition of duty. Appeal to common rational capacities is part of a ‘pedagogical strategy’ (Schönecker Reference Schönecker2009: 110). Philosophy can improve the way agents conduct their moral business, since it does not start as, and never becomes something that is alien to our ordinary practices. It is hence always possible to link the results of practical philosophy back to our practices and to modify our practices in light of the principles that we commit ourselves to when engaging in these practices. Ordinary agents and philosophers do not speak two radically different languages, and hence the philosopher, if she has something to say to the common agent can make herself understood, or the educator can at least translate between philosophy and ordinary agents.

Kant believes that his philosophy is different from theoretically sophisticated, ‘alien and irrelevant considerations’ (IV:404.27-8), and ‘perplexing speculations of the schools’ (V:35.16-18), which can deflect ordinary judgements from the straight course. Unlike these purely theoretical approaches to morality, Kant never loses sight of what he takes to be the point of practical philosophy: strengthening an agent’s ‘receptivity to a pure moral interest’ (V:152.33-35, see also A/B:829-30/857-8) with the goal of ‘cultivating and founding genuine moral dispositions’ (V:153.11).Footnote ⁴³ Kant believes that, if correctly communicated, making common agents aware of what they assume in their ordinary reasoning will secure their understanding against rationalizing, and the misleading philosophy rationalizing produces, as well as make them wish that they could be exemplary moral agents and, perhaps, even motivate them to strive towards this goal.Footnote ⁴⁴