Humanity as an Idea, as an Ideal, and as an End in Itself
Kant’s emphatic division of moral philosophy into a purely rational ‘metaphysics of morals’ and a more empirically influenced ‘practical anthropology’ or ‘moral anthropology’ poses significant interpretive challenges.1 One problematic area is the role that humanity can play in a rationally derived metaphysics of morals, since human beings are not purely rational and their characteristics seem to be known partly through empirical observation. Difficult questions arise even at the level of basic moral principles, since Kant says that the Categorical Imperative is meant to be a supreme principle of morality that is ‘grounded on pure reason alone, independently of all experience’ (Kant 2002: 210; G 4.409), and yet gives humanity a central role in one version of the Categorical Imperative, saying that humanity (die Menschheit) in oneself and others must be treated as an end in itself (Kant 2002: 230; G 4.429). The concept of ‘humanity’ in this ‘humanity formulation’ of the Categorical Imperative presumably must be accessible through reason alone, if Kant is to maintain a partition between purely rational morality and empirical ‘moral anthropology’. Furthermore, even when Kant turns to the application of basic, purely rational, moral principles to human beings, he at least sometimes maintains that this resulting ‘metaphysics of morals’ must be ‘scrupulously cleansed of everything empirical’ (Kant 2002: 190; G 388). How humanity can be the central object of concern in a rational, a priori moral principle, or in a system of moral duties that applies such principles to humans through reason alone, without taking their empirically known features into account, is not obvious.
But I think significant headway can be made on this problem by noting Kant’s technical account, in various writings, of what he calls an ‘idea’ and a corresponding ‘ideal’ of humanity. Within Kant’s overall philosophical system, the idea and the ideal of humanity provide purely rational concepts of humanity suitable for employment at the level of basic principles and of a resulting rational system of more specific duties. This use of Kant’s technical concepts also draws connections between his moral philosophy and other aspects of his critical philosophy, and sheds light on some otherwise obscure passages in his ethical writings.
I. The Idea of ‘Humanity’ as an End in Itself
Putting aside for now the interpretive issue of the extent to which an overall system of moral duties, or a metaphysics of morals, is meant to be accessible through reason alone, Kant is quite unambiguous in claiming that at least the basic moral principle, or Categorical Imperative, that underlies all specific moral duties must be known independently of all experience. Given this claim, the central role Kant assigns to humanity in one version of the Categorical Imperative, which says that humanity in oneself and others must be treated as an end in itself, poses an obvious interpretive puzzle.
Kant has said that basic moral principles must be ‘found completely a priori and free from empirical elements in concepts of pure reason’, and that these principles must not be sought for ‘in our knowledge of human nature (which we can get only from experience)’ (Kant 2002: 211; G 4.410). He adds that the type of end that can play a role in morality must be ‘given by reason alone’ so it can be ‘equally valid for all rational beings’ (Kant 2002: 228; G 4.427). He even explicitly says that the principle of treating humanity as an end in itself ‘is not borrowed from experience’ (Kant 2002: 231; G 4.431). Excluding empirical knowledge of humankind and individual humans from any role in the humanity formulation of the Categorical Imperative apparently requires some concept of humanity which can be delivered through pure reason, and which can serve as an end in itself.
Kant does describe such a concept of humanity, derived from reason rather than empirical observation, namely what he calls an ‘idea’ of humanity.2 Kant’s most explicit discussions of the rational idea of humanity are in Critique of Pure Reason, but he seems to employ, and make recurring reference to, this idea of humanity throughout his central writings on moral philosophy.
In Critique of Pure Reason, Kant offers a technical definition of an ‘idea’ as ‘a necessary concept of reason’, and says ‘no congruent object can be given in the senses’ (Kant 1998a: 402; CPR A327). Although Kant devotes much more space in Critique of Pure Reason to discussing concepts of the understanding, he repeatedly acknowledges that we also have these ‘pure concepts of reason’, or ‘transcendental ideas’, which are ‘not arbitrarily invented, but given as problems by the very nature of reason itself’ (Kant 1998a: 402; CPR A327). From the standpoint of theoretical reason, such a concept may seem empty, since it is ‘only an idea’—that is, nothing corresponding to the idea can ever be encountered empirically. But in the practical use of reason, in deciding what to do, such ideas are ‘always fruitful in the highest degree’ (Kant 1998a: 403; CPR A328), because an idea guides practical reason to ‘bring forth what its concept contains’, so it ‘must serve as a rule, the original and at least limiting condition, for everything practical’ (Kant 1998a: 403; CPR A328). As an example, Kant gives ‘our idea of perfect humanity’ (Kant 1998a: 551; CPR A568), and says, ‘Virtue, and with it human wisdom in its complete purity, are ideas’ (Kant 1998a: 552; CPR A569). Kant’s position is that we have a concept of humanity which is produced by reason rather than experience, and that it includes human rational perfection, and moral goodness or virtue. This idea of humanity does not include empirical features of human beings (their size, physical abilities, colorations, the sound of their voices) but instead the features related to humans as rational beings -- knowers and agents. So, to somewhat speculatively fill out Kant’s position, the idea of humanity would seem to include the possession of reason in its theoretical use and its practical use. This includes, as aspects of practical reason, the power of choice and the power to legislate practical moral principles (Willkür and Wille, to use Kant’s later distinction). But beyond this, as an idea of virtue, or properly functioning human reason, it includes the characteristic of placing priority on moral principles over inclination.3 So the idea serves as a practical ‘model of virtue’ and serves a regulative function as a standard to live up to, and ‘it is only by means of this idea that any judgment as to moral worth or its opposite is possible’ (Kant 1998a: 396; CPR A315 ).
Kant is surprisingly persistent, throughout many writings of the critical period, in assigning this regulative, action-guiding role to rationally produced ideas, and specifically to the idea of humanity as human virtue and reason. In a note in Critique of Practical Reason, he says that ‘moral ideas’ (‘If I understand by such an idea a perfection to which nothing adequate can be given in experience’) serve as ‘the indispensable rule of moral conduct and also as the standard of comparison’ (Kant 1997a: 106; C2 5.127). Similarly, in Groundwork, he explains moral motivation by saying ‘…here pure reason by means of its Ideas (which furnish absolutely no objects for experience) has to be the cause of an effect admittedly found in experience’ (Kant 2002: 259; G 4.460). This repeats his position in Critique of Pure Reason, that ‘in morality’ ‘human reason shows true causality’, and ‘ideas become efficient causes (of actions and their objects)’ (Kant 1998a: 397; CPR A317). And in the same passage, cited above, in which Kant identifies ‘virtue’ and ‘human wisdom in its complete purity’ as ideas, he also says, ‘…in regard to the principle through which reason places limits on a freedom which is in itself lawless, they can nevertheless serve quite well (if one attends merely to their form) as examples of pure concepts of reason’ (Kant 1998a: 552; CPR A569). There is, then, a sustained line of thinking in Kant’s texts, that the power of reason produces an idea of humanity, and that this idea is meant to play an action-guiding role in practical deliberation.
Further examination of Groundwork and The Metaphysics of Morals, specifically of the passages in which Kant directly discusses humanity, reveal even more direct evidence for taking ‘humanity’ in the humanity formulation of the Categorical Imperative to be the rational idea of humanity. Kant’s initial presentation of the humanity formulation provides only ambiguous support for this ‘rational idea’ reading. Most English translations do have Kant saying that if there is to be a Categorical Imperative at all, ‘it must be such that it forms an objective principle of the will from the idea of something which is necessarily an end for everyone because it is an end in itself’ (Kant 2002: 229; G 4.428-9), suggesting that what underlies the humanity formulation is an idea of humanity. However, the German word Kant uses for ‘idea’ here is die Vorstellung, not the same word he uses in Critique of Pure Reason to describe an idea in the technical sense of a concept provided by reason – that word is die Idee. But a few pages later in Groundwork, he does closely identify die Idee of humanity with the Categorical Imperative’s requirement to treat humanity as an end in itself, equating ‘the mere dignity of humanity as rational nature’ with ‘respect for a mere idea [eine Idee]’ (Kant 2002: 239; G 4.439). Similarly, Kant follows this with the claim that the proper object of respect is an ‘ideal will, which is possible for us’, or, in German, a will that is possible for us ‘in der Idee’ (Kant 2002: 240; G 4.440). And in MM 451, in explaining why beneficence to oneself is merely a permission rather than a duty, Kant grants that, ‘…lawgiving reason , which includes the whole species (and so myself as well) in its idea of humanity as such, includes me as giving universal law along with all others…’ (Kant 2002: 200; G 4.451). These passages, along with others given below as evidence for more specific interpretive points, support taking Kant’s position as being that the ‘humanity’ that plays a central role in the Categorical Imperative must be an idea of humanity, presented by reason as a concept of perfected human reason and virtue.
The only other apparent candidate that emerges from Kant’s Critical writings, for supplying a rationally derived concept of humanity that can play a role in a purely rational moral principle, is what Kant calls an ‘ideal’ of humanity. This ideal of humanity poses no dire threat to the reading defended above, which takes ‘humanity’ in the humanity formulation to be the idea of humanity, since the ideal of humanity is itself derived (through reason, not experience) from the idea of humanity, and it also is a concept of humanity as perfected human reason and virtue. The difference is that while an idea is general, a corresponding ideal is given ‘in individuo, i.e., as an individual thing, which is determinable, or even determined, through the idea alone’ (Kant 1998a: 551; CPR A568). To gain insight into Kant’s meaning here, it is useful to turn to Critique of Judgment, where Kant explains that ‘Idea properly means a rational concept, and ideal the presentation of an individual being as adequate to an idea’ (Kant 1987: 80; C3 5.232). Despite being individual and specific, the ideal is still produced by reason rather than being known in experience, but it is a more specific concept than the idea of virtue, inasmuch as it is a concept of what a human being would have to be like in order to actually be virtuous. Although Kant does sometimes seem to slide between regarding humanity as an idea and as an ideal, the more fundamental rational concept is the idea of humanity, and this seems to be the concept of humanity that is employed in the humanity formulation of the Categorical Imperative. I will argue below that the corresponding, but more specific, ideal of humanity is better suited to play a role in a rational metaphysics of morals that is based on the Categorical Imperative.
If, despite the textual evidence, the idea of humanity seems somehow too abstract to be equivalent to the humanity that is an end in itself in the humanity formulation, it may help to consider Kant’s discussions of ends in Groundwork and Critique of Judgment. Kant defines an ‘end’ as something that serves the will as a ground of its self-determination, or as something that directs one’s actions (Kant 2002: 228; G 4.427). A concept can do this, if it is ‘regulative’ or action-guiding, and a concept that is presented by reason alone as necessarily action-guiding, would be what Kant calls an ‘objective end’ or an end in itself. Kant describes the idea of humanity as such a necessarily action-guiding concept, in the passages from Critique of Practical Reason in which he defines die Idee. Kant’s discussion of a thing’s end (or ‘purpose’ in some translations, but the same German word, der Zweck, is translated as either) in Critique of Judgment further supports taking the idea of humanity as the end in itself. Kant says that ‘insofar as the concept of an object also contains the basis for the object’s actuality, the concept is called the thing’s purpose’, or end (Kant 1987: 20; C3 5.180). Since the concept of humanity is presented by reason itself as a regulative concept that guides action by demanding that one live up to its standard of perfection, the concept itself is necessarily an end for every rational being. Or, in other words, it is an end in itself.
If the ‘humanity’ that has a central role in the humanity formulation of the Categorical Imperative is an idea of perfected humanity that is produced by reason, this has some significant ramifications for our understanding of the principle. For one thing, it means that the starting point for Kant’s ethics is not to claim that every actual human individual we encounter is an end in herself. Of course, his ethical system ultimately is meant to provide guidance on how to treat particular humans, but that is an ending point, rather than a starting point, of his overall system, and it requires intervening steps of ‘applying’ the Categorical Imperative to experience, steps for which Kant acknowledges the need in developing his ‘metaphysics of morals’.
If the humanity formulation is understood as relying on a rational idea of humanity, then recent approaches to understanding the humanity formulation also stand in need of some clarification and revision. Most recent commentators have taken ‘humanity’ in the humanity formulation to refer to ‘a characteristic, or some set of characteristics, of persons’ (Hill 1992: 39). Although there is no unanimity regarding exactly which characteristics (the power to set ends, the capacity for morality, a good will) are the morally relevant ones in marking a person as an end in herself, recent approaches share the assumption that Kantian ‘humanity’ essentially is some set of characteristics possessed by humans.4 But taking humanity as a rational idea adds a layer of depth, and an additional requirement, to this claim. What is added by taking humanity to be a rational idea is the explanation of which characteristics are the relevant ones, and why. The relevant characteristics, if we take humanity to be an idea of reason, presumably are the power to set ends, the possession of theoretical reason and understanding, the capacity to legislate moral principles to oneself, and the prioritizing of moral principles over inclination. The reason these are the relevant characteristics is not because we observe empirically that some, all, or most humans have these traits, nor because our moral intuitions tell us they are what makes a person morally significant. It is because the only concept of humanity that can feature centrally in a purely rational moral principle is the rationally produced idea of humanity, which is an idea of perfected humanity and virtue.
Of course, defenders of other readings of ‘humanity’ may resist taking humanity to be a concept of perfected human reason and virtue, but their resistance does seem to require rejecting the entire approach of taking ‘humanity’ in the humanity formulation as being equivalent to the rationally produced idea of humanity. It is not only that Kant consistently says, in Critique of Pure Reason, that this idea of humanity is a concept of human virtue, nor is it just that no other rationally produced concept of humanity is mentioned, or obviously available, in Kant’s philosophy (except for the rational ‘ideal’ of humanity which is derived from the idea). There also is a Kantian rationale for thinking that a concept of humanity delivered by reason actually must be a concept of perfected, properly functioning human reason. Kant maintains that experience can never tell us what belongs necessarily to a concept (Kant 1996: 18; MM 6.226-227). He says this in order to explain why freedom can not be defined as freedom to choose between moral and immoral action, and adds ‘Only freedom in relation to the internal lawgiving of reason is really an ability; the possibility of deviating from it is an inability’. Reason can only deliver to us a concept of a properly functioning rational being, who acts in the ways reason demands. It is true that ‘experience proves often enough’ that people also can act contrary to what is rationally .and so, morally) required, but ‘we still cannot comprehend how this is possible’ (Kant 1996: 18; MM 6.226).5 Reason can only tell us what a proper or perfected human reason is, and the fact that particular human beings fall short of this is only known by experience.
Elsewhere in The Metaphysics of Morals, Kant appears to remind the reader that the concept of humanity underlying all duties is a concept of perfected human virtue. To explain why an individual must leave punishment of wrongdoers to the legal system, rather than undertaking it privately, Kant says that ‘in ethics’ we must ‘regard human beings as in a rightful condition but in accordance only with laws of reason (not civil laws)…’ (Kant 1996: 207; MM 6.460). On the next page, he expands on this idea, saying that although we can observe individual humans’ moral shortcomings, this ‘does not justify attributing to them a predisposition to these vices belonging to their species, any more than the stunting of some trees in a forest is a reason for making them a special kind of plant’ (Kant 1996: 208; MM 6.461). His concern here is not an accurate empirical description of humanity as a biological species, but on obtaining an accurate rational concept of humanity. He says ‘…any vice, which would make human nature itself detestable, is inhuman when regarded objectively. But considered subjectively, that is, in terms of what experience teaches us about our species, such vices are still human.’ And he explains that we can not regard humans as both virtuous and vicious, since ‘dividing something into two heterogeneous things yields no definite concept at all…’ (Kant 1996: 208; MM 6.461). Passages like these, along with the Groundwork claim already cited above that the proper object of respect is an ‘ideal will, which is possible for us’ (Kant 2002: 240; G 4.440) are evidence of Kant’s sustained commitment to the rational idea of perfected human reason and virtue as being the concept of humanity in the humanity formulation, and so as the concept of humanity at the heart of his ethical system.
II. Humanity as an Ideal in the Purely Rational (?) Metaphysics of Morals
Even if the Categorical Imperative is meant to be a purely rational principle, there is still room to wonder whether Kant means the entire metaphysics of morals, which is comprised of not only the Categorical Imperative but also the more detailed system of duties based on that underlying principle, to be exclusively a product of reason. Although it sometimes appears that Kant is applying the (rationally produced) Categorical Imperative to empirical circumstances in The Metaphysics of Morals, I will argue that we should take seriously his own claims that the entire metaphysics of morals is purely rational, and does not take empirically known features of humans into account. If this is right, then only rational concepts of humanity must figure in the metaphysics of morals. I propose that the only concepts of humanity that play a role in the metaphysics of morals are the rational idea of perfected human virtue, and the derivative, more specific, rational concept that Kant calls an ‘ideal’ of humanity.
There is certainly prima facie textual evidence that Kant means the metaphysics of morals to be purely rational, and so means it, like the Categorical Imperative on which it is based, to employ only rationally produced concepts of humanity. Kant says that the ‘empirical part’ of ethics, or its application to human individuals, should be given the title ‘practical anthropology’ (Kant 2002: 190; G 4.388) and he goes on to reiterate that it is ‘a matter of utmost importance, to forge for once a pure moral philosophy, completely cleansed of everything that may be only empirical and that really belongs to anthropology’ (Kant 2002: 191; G 4.389). So, ‘Pure philosophy (metaphysics) must therefore come first, and without it there can be no moral philosophy at all’ (Kant 2002: 192; G 4.390). In Chapter Two of Groundwork, he reiterates that a metaphysics of morals is meant to be ‘found completely a priori and free from empirical elements in concepts of pure reason and absolutely nowhere else to the slightest extent’and that such a ‘completely isolated metaphysics of morals, mixed with no anthropology, no theology, no physics or hyperphysics...’ is an ‘indispensable underlying support for all theoretical and precisely defined knowledge of duties’ ((Kant 2002: 211-212; G 4.410). He repeats two pages later that in ethics, ‘pure philosophy’ or ‘metaphysics’ must be ‘expounded independently’ of all anthropology (Kant 2002: 213; G 4.412). Kant presents a consistent overall picture in Groundwork, that moral philosophy has two parts, a purely rational part that he calls a ‘metaphysics of morals’, and an empirical application of the rules of the metaphysics of morals to actual human beings, which he calls ‘anthropology’.
But it may appear that his views, or at least his terminology, change between Groundwork and The Metaphysics of Morals. In the latter work, Kant often includes details of human life, including elements like the existence of shops and commerce, the effects of consuming alcohol, and the practice of selling one’s hair and teeth. He also devotes considerable space to the treatment of criminals and wrongdoers, which is hardly compatible with viewing humans only as perfectly rational and virtuous (e.g. Kant 1996: 104-110; MM 6.331-337, and 210; MM 6:463). Passages like these naturally make it tempting to think empirical observation plays a role in Kant’s metaphysics of morals, and to read his own descriptions of his project as allowing that possibility. For example, near the beginning of the book, he says that
…a metaphysics of morals cannot dispense with principles of application, and we shall often have to take as our object the particular nature of human beings, which is cognized only through experience, in order to show in it what can be inferred from universal moral principles. (Kant 1996: 10; MM 6.216-217)
One plausible reading of this passage is that the ‘principles of application’ which take empirically observed features of humans into account are actually part of the metaphysics of morals, which implies that Kant has abandoned the claim that a metaphysics of morally is purely rational. And when Kant says, later in the book, that ‘practical philosophy’ is like other philosophy in needing to be based on ‘a system of pure rational concepts’ or ‘metaphysical first principles’, it may be thought that Kant is only identifying the various formulations of the Categorical Imperative as purely rational ‘first principles’, with the rest of the metaphysics of morals incorporating empirical observation (Kant 1996: 141; MM 6.375).