Kant’s Critique of Practical Reason: A Philosophy of Freedom

By Otfried Höffe

Published in English for the first time, Kant’s Critique of Practical Reason is a slightly abridged and updated edition of Professor Höffe’s groundbreaking work originally published in German. In the book, the author systematically introduces one of the most important areas of Kant's philosophy, and relates its basic ideas to the debates of today.  

The first part introduces the four driving forces that motivated Kant’s practical philosophy and which are still relevant today: Enlightenment, critique, morality and cosmopolitanism. The second part demonstrates the extent to which Kant revolutionised moral philosophy. In the third part, the author explains the provocations that lie at the heart of Kant’s practical philosophy. The remaining parts deal with political philosophy, the philosophy of history, and Kant’s thinking about religion and education.

• Language: English
• Publisher: University of Wales Press
• Release date: Sep 15, 2023
• ISBN: 9781837720477

Otfried Höffe

Otfried Höffe is Professor Philosophy Emeritus at the Eberhard Karls University in Tübingen, Germany and director of the Research Center for Political Philosophy.

Book preview

1 • Introduction: Four Motivating Forces

An in-depth exegesis of Kant’s texts must confront three tasks: the micro-analysis of narrowly defined problems; the meso-analysis of wider problem fields; and the macro-analysis of a comprehensive problem area. Before this investigation engages in meso-analyses and macro-analyses, a broader overview suggests itself as an introduction. When widened to a panoramic view of the entire, especially critical, œuvre, such an overview identifies four pre-eminent motivating forces in Kant: the Enlightenment, defined principally as thinking for oneself; the methodological goal of a critique in the style of a judicial trial; morality as the leitmotiv already defining the first Critique; and a comprehensive cosmopolitanism.

These are not separate motivating forces, and each is perhaps relevant for different thematic areas; that is, with critique applicable to theoretical philosophy, morality and enlightenment to the whole of practical philosophy, and cosmopolitism to the philosophies of law, politics and history. They are linked to each other by Kant’s three famous questions – What can I know? What should I do? What may I hope? – and constitute the different aspects of one complex motivating force, which Kant, however, does not explicitly identify. In the case of morality, it amounts to an enlightenment of moral consciousness about itself. In the process, thinking for oneself is joined to a criticism of ethical misinterpretations, which in turn is based on a moral interest, and moreover on an existential and simultaneously universalist interest, which, as such, has a cosmopolitan character.

The question raised in the Preface, ‘what in Kant still matters to us today?’, can, in these introductory remarks, already be given an assertive answer as far as the four motivating forces are concerned: all four are indispensable, for Kant’s philosophy as well as for contemporary civilisation. Tied neither to particular cultures nor to a specific historical period, they are highly welcome in our contemporary age of globalisation.

1.1 Enlightenment

A few years after the publication of the Critique of Pure Reason, Kant proved that he had more to offer in terms of thematic content as well as literary form – both the new themes and the new literary genre were interwoven and, as is usually the case with great philosophers, mutually interdependent. While writing the comprehensive and rigorous new foundation for philosophy addressed to his academic colleagues, as well as the Prolegomena for ‘future teachers’ (Proleg., IV, 255), he turned to other themes in order to reach a wider public, striking the appropriate tone with respect to content and meeting the requirements of readability. In doing his groundwork for a new foundation of philosophy Kant does not discuss precisely the same topic, this time – as a result of his didactic skills – he presents it in an understandable fashion for a non-academic audience. Rather than undertaking a popularisation of his transcendental critique, he turns to new topics while still acknowledging his critical (i.e., transcendental) turn – topics that were of interest to a wider audience.

Within a short time, Kant had published profound essays in the Berlinische Monatsschrift,¹ including Idea for a Universal History from a Cosmopolitan Point of View (1784), Conjectural Beginning of Human History (1786) and What Does it Mean to Orient Oneself in Thinking? (1786). Regarding their impact, however, these works were all overshadowed by a fourth essay, An Answer to the Question: What is Enlightenment? (1784). In response to this question – what is enlightenment? – which was raised by a church official, such eminent intellectuals as Gotthold Ephraim Lessing, Moses Mendelssohn, Christoph Martin Wieland and Friedrich Schiller sent in their answers. Yet only Kant’s answer left contemporary issues far behind, became famous beyond the German language of its origin and earned the status of a classical text.

Its central themes – maturity, thinking for oneself, the liberation of human reason in general – count to this day as the central characteristics of Enlightenment thought. However, one tends to overlook that these themes did not simply articulate the ‘essence’ of the era, but instead they develop a new and simultaneously provocative concept. In this way, the text offers the classic example of a truly political philosophy. Moreover, it articulates one of the four motivating forces essential not only for Kant’s political thought, but also for his philosophy of morals, religion and education, even of knowledge.

Kant’s provocation was the following: a historical movement on which his contemporaries, especially the leading figures, looked – almost complacently – with pride becomes an on-going systematic task. In the process, Kant abandoned the fundamental meaning at the heart of the term ‘Auf-klärung’ (‘En-lightenment’). What was important to him was not clear insight (i.e., an increase in knowledge). The place of a theoretical gain is taken by a moral task that consists of nothing less than a revolution of inner attitude, a revolution of one’s outlook on the world. This task includes the critique of the absolutist state and of a Church orientated towards power – although one cannot, as Brandt (2010, 175) suggests, reduce it to this.

The beginning of the Enlightenment essay already mentions the moral motive: ‘Enlightenment is the emergence of humanity from its self-inflicted immaturity’ (Enlightenment, VIII, 35). In his Anthropology from a Pragmatic Point of View, Kant identified this ‘exit’ as a ‘revolution from within the human being’, he qualified it by a superlative as the ‘most important revolution’, and gave the following clarification: ‘Before this revolution he let others think for him and merely imitated others … Now he ventures to advance, though still shakily, with his own feet on the ground of experience’ (VII, 229).

Even before the Enlightenment essay, in his Idea for a Universal History from a Cosmopolitan Point of View, Kant spoke of enlightenment, called it ‘a great good’, maintained that the ‘enlightened individual’ unavoidably ‘takes a certain interest in the good’, and expected the Enlightenment to extend to rulers (i.e., to influence their constitutions) (VIII, 28). The Enlightenment essay even takes a further step in that it focuses on the achievement of each individual, including that of the common citizen. This is followed by the famous and succinct formulation known as the ‘Slogan of the Enlightenment’, which pointedly expresses the concern of Enlightenment and not just of a historical era.

The Age of Enlightenment, the long eighteenth century, was proud of its struggle against superstition, of the near explosive expansion of knowledge in the human, social and natural sciences, of its discoveries and inventions, as well as of the increase in medical and technical skills. By contrast, Kant’s famous definition from the Enlightenment pamphlet, ‘Sapere aude! Have the courage to make use of your own understanding!’ (Enlightenment, VIII, 35) contains a rarely noticed provocation (in Taylor, 2012, it is likewise neglected.) It pushes all these achievements aside and instead emphasises the practical task: the courage to think for oneself.

Two years later, in What Does it Mean to Orient Oneself in Thought?, Kant refuses emphatically to ‘place enlightenment in the in the acquisition of information’ (VIII, 146),² which contains a clear jab at the French project of an Encyclopédie, in particular at its expectation that the knowledge collected in the Encyclopédie would ‘make our grandchildren not only more educated, but at the same time [!; my emphasis] more virtuous and happier’ (Encyclopédie, V, 635).

In contrast to the prevailing self-understanding of the epoch as the ‘siècle des lumières’ and the ‘epoch of enlightenment’, Kant’s alternative assessment that enlightenment is human beings’ ‘emergence from their self-incurred immaturity’ (Enlightenment, VIII, 35), emphasises an inner revolution, which, in principle, everyone is capable of effecting. Kant’s interest in enlightenment is firmly of a moral-practical and democratic nature, and is in support only of the practical interest that is also of a theoretical nature.

According to Kant, the essence of enlightenment is not an achievement of the intellect, but rather of character. It follows that what Kant considers to be important is not sagacity, brilliance, creativity and originality, but rather mental effort and intellectual courage. Kant’s first provocation of the traditional understanding of enlightenment, the turn from theoretical to moral and practical concerns, is combined with a second provocation: the rejection of any intellectual aristocracy in favour of a democracy that pertains to intellectual matters as well.

1.2 Critique in the Style of a Judicial Trial

There is good reason to distinguish between two phases in Kant’s intellectual development, because between them lies a period of radical change: the silent decade in which Kant did not publish anything. If we follow the decisive texts, then the philosophy of freedom – and, simultaneously, of morality – falls entirely into the second phase. Nevertheless, it is right to note that the usual description of the two phases as ‘pre-critical’ and ‘critical’, respectively, is misleading, since the critical impulse is not a late motivating force, but one that guides Kant from the beginning.

In the very first sentence of Thoughts on the True Estimation of Living Forces, Kant self-confidently takes the liberty that is the hallmark of true criticism: ‘to contradict great men’ (Thoughts, I, 7). According to a well-known saying that goes back to Aristotle, ‘Amicus Plato, magis amica veritas’ (loosely translated as, ‘I love Plato, but I love truth even more’), for Kant, the discovery of truth is likewise more important than the acceptance of scientific authorities, which in his time were, above others, Newton and Leibniz.

By taking the liberty in his first work to ‘unabashedly’ rebuke virtually all the opinions that had thus far been put forward and to give preference to his own thoughts in their place, Kant was motivated from the outset by thinking for himself – that is, by enlightenment, as he himself understood it, and consequently by criticism. As already mentioned, both motives – enlightenment and critique – prove to be intertwined.

As a rejection of external authorities, Kant’s critique is initially of a primarily negative nature. In accordance with contemporary common parlance, it aims at disapproval, objection and contradiction. In the three Critiques, however, another, neutral meaning comes to the fore. In this sense, it applies to Kant’s entire œuvre on moral philosophy: a critique in the style of a judicial trial.

As is well known, the occasion for the critique is the dispute between rationalism and empiricism, prevailing at the time in fundamental philosophy. Kant takes neither side; nor does he allow the decision to be arbitrary or a matter of might. Instead, he turns it over to the conditions of the rule of law and stages a trial. Primarily, it is a civil trial that does not want to condemn or to acquit a defendant, but wants instead to test whether claims or, more precisely, knowledge’s claims of reason and metaphysics are justified. For the final judgement to be convincing, Kant takes to heart the principle of his first motivating force, thinking for oneself: that reason may neither act anarchically nor according to external laws, but that it submits exclusively to the laws it gives to itself (What Does it Mean, VIII, 145).

Although Kant largely follows the pattern of a civil court case, we find elements of a criminal trial in the dialectic. As soon as reason steps beyond the limits of its legitimate employment, it is ‘punished’ by false conclusions, in the second Critique by a contradiction (i.e., the antinomy between happiness and virtue). No esoteric special knowledge is allowed in the trial staged by Kant, only common reason that, albeit only darkly, everyone has at their command. Even the trial of theoretical reason is, in the final analysis, not conducted by academically educated specialist philosophers. Carried out as a ‘free and open examination’ (CopR, A, xi),³ the trial takes it for granted that everyone is recognised as equal; and it is no different in the Critique of Practical Reason and Kant’s other texts on moral philosophy.

Referring to G. H. Mead, the discourse ethicist Jürgen Habermas (1983, 75) has called for an ideal role reversal in moral philosophy. Kant not only recognised this need long before Mead – in accordance with the second stage of enlightenment (i.e., ‘thinking in the place of everyone else’) – he even carried it out in the singular form of a truly universal role reversal. Since no esoteric special knowledge counts – in any case, not the ‘private validity of the judgement’ (CopR, B, 849) – but reason alone, which everyone possesses in principle, every (self-)thinker plays all three necessary roles in the trial of reason: the role of the prosecutor, the defence lawyer and the judge. In the ‘Doctrine of Method’ of the first Critique it is stated clearly that the judgement of reason, its ‘pronouncement’, ‘is at all times nothing but the agreement of free citizens, each of whom must be able to express his or her doubts, even his or her veto, without restraint’ (B, 766 f.). These are the words of the Enlightenment philosopher who vehemently advocates public use of reason, which does not demand the possession of expert knowledge, the membership of a special class or the holding of a special office, whether by the grace of God or man. In the trial of reason initiated by Kant, laymen – and, in principle, laymen only – sit in judgement.

The critique of pure reason presupposes the courage to use one’s own intellect, demanded in the pamphlet What is Enlightenment? The ability to critique reason is owed to the corresponding courage (i.e., to a moral achievement), and the inability can likewise be traced back to a moral, in this case negative, ‘achievement’: one remains immature due to a lack of courage and because of indolence. The fact that in matters of reason everyone is a judge, even a judge of principles – insofar as they are a constitutional judge – if they only summon up the courage, as well as the necessary thoroughness and patience, is affirmed by Kant’s mode of presentation. The three Critiques occasionally recall certain positions from the history of philosophy, especially when the problem that calls for the trial would otherwise be unclear: the dispute among philosophers. If we take the first Critique as an example, Kant sets the scene primarily in the prefaces, and even there limits this task inasmuch as he provides only minimum information from the history of philosophy. As soon as the trial is presented as necessary (i.e., as soon as it is opened), Kant lays out the relevant problems, formulating and dealing with them directly and systematically, without an extensive engagement with the history of philosophy.

In today’s terms, a reason that consists in the ‘agreement of free citizens’ (CopR, B, 766) is, like the Enlightenment qua thinking for oneself, fundamentally democratic. The relevant trial takes place in a court of laymen or before a jury, as it were, in which lay judges are given the same vote as professional judges (i.e., trained philosophers).

1.3 Morality

Kant’s third philosophical motivating force, morality, could be taken for granted in a philosophy of human agency. In fact, it can be taken for granted only as an obvious subject, not as a motivating force. Morality and the other aspects of human agency (i.e., law and the state, history, the theory of education and religion) can be examined out of purely theoretical interest. Kant, on the other hand, discusses them, like almost all the themes of his thinking, from a moral interest. This, perhaps surprising, claim that morality is a general motivating force for Kant’s philosophy, emerges particularly clearly for the Critique of Pure Reason in the preface to the second edition (cf. Höffe, 2004a). According to this text, philosophy ultimately serves the only necessary purpose: morality, in that it has the advantage of ‘putting an end, for all future time, to all objections against morality … in the Socratic manner, viz., by the clearest proof of the opponents’ ignorance’ (B, xxxi). From this follows my heterodox, even heretical, reading: while the Critique of Pure Reason examines knowledge and, beyond that, hope, it places both in the service of moral obligation; namely, morality, which increases the value of morality and of moral philosophy to a very large degree.

Contrary to a long tradition, which extends at least from Aristotle to Descartes, morality is awarded the dignity of being an integral part of fundamental philosophy (i.e., metaphysics). Within the two main parts of metaphysics, theoretical and practical metaphysics, or the metaphysics of nature and the metaphysics of freedom (i.e., of morality), practical metaphysics is assigned preeminence, since its object, morality, has priority over theoretical reason. The reason for this lies in Kant’s new concept of morality (i.e., that he defines it as pure practical reason). A second, indirect upgrading of the value of morality is added by showing that regarding the three themes of the traditional metaphysica specialis – the soul, freedom and God – we are barred from all knowledge, Kant declares that claims of theoretical metaphysics in conflict with morality are unjustified. In this way, he places the previous metaphysics (i.e., its pure theoretical reason) in narrow confines, thereby, in return, raising the status and scope of pure practical reason (i.e., morality).

This motivation does not reach back to the start of his philosophising. At first, Kant was more interested in natural philosophy, and he pursued purely theoretical interests. As early as the mid-1760s, however, he turned to questions of natural theology and morality, which would become the guiding questions of the first Critique. Anyone who reads the first Critique up to its final section, the ‘Doctrine of Method’, will discover what is already alluded to in the motto and in the preface to the second edition: in the final analysis, Kant not only wants to demonstrate pre-empirical conditions of empirical knowledge, but also to fathom the possibility of metaphysics, especially the prospects for morality and theology.

In one of his lectures on metaphysics, ‘Metaphysics L1 Cosmology, Psychology, Theology according to Pölitz’, Kant affirms unequivocally (it was even emphasised by spaced lettering) that the ‘main thing is always morality: this is the sacred and inviolable thing we must protect, and this is also the reason and purpose of all our speculations and investigations’. For (now no longer printed with spaced lettering) ‘if the concepts of God and another world were not connected with morality, they would be useless’ (XXVIII/1, 301). Could there be, it remains to be asked, a competition of motives here? The moral key objective of the Critique of Pure Reason is not added to its second edition retrospectively, on the contrary, it already dominated the first edition. And yet, the first Critique seems to serve two different masters: on the one hand, from the introduction to the transcendental aesthetics, and transcendental analytics to the transcendental dialectics, the subject matter of primary concern is knowledge; on the other hand, the additional subject matter of the ‘Doctrine of Methods’ is human agency, particularly morality, and hope.

According to the orthodox, primarily theoretical reading, Kant chiefly writes in the service of the theory of knowledge; however, he is gratified to see – so the heterodox reading says – that this service also helps morality. In this reading’s favour (i.e., that the service to morality is secondary and complementary), speaks the fact that over hundreds of pages the first Critique pursues purely theoretical problems and that only towards the end it discusses those three topics – the freedom of the will, the immortality of the soul and the existence of God – of which Kant says expressly that the theoretical interest in them is very little (cf. CopR, B, 826). On the other hand, the practical, even public interest is great, since it cuts off the roots of generally harmful teachings (e.g., materialism, fatalism and atheism) (CopR, B, xxxiv). Consequently, a second, not merely complementary, but primarily practical (i.e., precisely the heretical reading) is preferred. According to this reading, the service of knowledge is the only, admittedly indispensable, means for that main practical purpose (i.e., ‘morality’), which alone ‘actually counts in the establishment of our reason’ (CopR, B, 829). This is why in the Critique of Practical Reason Kant says that ‘all interest [of reason] is ultimately practical and even the interest of speculative reason is only conditional and is complete in practical use alone’ (CpR, V, 121).⁴ And this is why primacy lies with practical reason.

1.4 Cosmopolitanism

Cosmopolitanism suggests itself, above all, for the association of philosophy and politics. According to our contemporary understanding, the honorary label ‘cosmopolite’ or ‘citizen of the world’ may be bestowed on those who are able to transcend the borders of the state, and in addition those of ethnicity, language, culture and perhaps even religion. This is why, today, we give the term a primarily political meaning. However, since its beginnings, philosophy has known a far more comprehensive sense. The reason is obvious: the cognitive foundation of philosophy, wherever it arises and develops, is not an ethnically bound (e.g., Eurocentric) ability. Its driving force, and simultaneously its medium, is universal human reason, which transcends all political boundaries.

This reason can definitely combine with experience. Even with Kant, the great advocate of synthetic a priori knowledge, philosophy is not exclusively committed to pre-empirical thought. However, the experience to which – if the circumstances require it – philosophy refers, tends to be general human experience. Even when philosophy defends the rights of particular groups (e.g., the rights of minoritised groups), it cites generally convincing arguments. So, although philosophy, by its very nature, transcends particular boundaries, not one of its formidable representatives thinks in a comprehensively cosmopolitan way. The only exception – and, at the same time, the one that is still authoritative today – is Kant. To begin, his exceptional importance rests on the fact that any Eurocentric arrogance is alien to him. Insofar as he deals with Europe at all, he is primarily interested in internal differences: in the lecture on Physical Geography he is interested in geographical internal distinctions, and in the Anthropology (VII, 316 f.) he is interested in internal differences in mentality. Thus, in both cases, he turns to Europe’s wealth of diversity, not to commonalities that have allowed the continent to place itself at the centre of the world (i.e., to think Eurocentrically and to raise this Eurocentricity to a feeling of superiority).

Kant’s thought is characterised by a general cosmopolitanism, not Eurocentric arrogance. In this way, he advances a basic idea of the epoch (see, e.g., Cavallar, 2005; Cheneval, 2002; Coulmas, 1990; and Kleingeld, 1999), cosmopolitanism, which was often restricted to economics and occasionally extended to politics, with a far more comprehensive, more fundamental and in many respects novel meaning. In Kant, cosmopolitanism becomes a driving force encompassing his entire philosophy.

Kant develops a cosmopolitan philosophy for the most important building blocks of every culture: knowledge; morality; the unity of the two worlds of nature and of morality or freedom; the theory of education; via the sensus communis for the world of art; legal thought; and the world of history (for no fewer than seven different subject areas). His philosophy is characterised by an intercultural and transcultural relevance that makes it cosmo-politan, capable of being globalised.

In addition, there are three elements of the field of politics that are so formal they cannot be confined to politics in a straightforward sense – they already appeared in the Critique of Pure Reason: (1) the challenge for a moral politics is presented by the state of nature, which has the character of a state of war (CopR, B, 779 f.); (2) the triumph of moral politics over the state of war takes place by means of principles that can be generalised, which exemplify a constitutional state, which for Kant, in this context, is an epistemic republic; and (3) its purpose consists in an unconditional, and thus eternal, peace that serves the whole of humanity, which is the third criterion of cosmopolitanism.

The epistemic peace established by the first Critique serves two ‘entities’: it directly serves knowledge, yet ultimately serves morality. Since both form the basis of the philosophies of law and peace, precisely this sequence is required: first, cosmopolitanism with regard to knowledge, then – for Kant, even more importantly – cosmopolitanism in matters of morality. Moreover, only on the basis of these two prior conditions can the third form of cosmopolitanism, its legal or political form in the narrower sense, be justified.

Incidentally, Kant subjects his own intellectual biography to precisely this systematically demanded sequence, which supports my incidental claim that in the life of Kant, biographical and genuine philosophical cosmopolitanism engage one another. Since the early 1760s, our philosopher had been concerned with the principles of morality. According to his library, he studied works on the philosophy of law from around the same time, 1762–4. From the summer semester of 1767 onwards, he even lectured on the philosophy of law (‘Naturrecht’). Nevertheless, within his critical philosophy, he devotes himself first to the problems of epistemology, then to those of ethics and morality, and only lastly to those of the philosophy of law in the relevant respect.

According to the ‘heretical reading’ advocated in this study, the Critique of Pure Reason is – in the final analysis – not interested in knowledge but in morality (see Chapter 3 of this volume). In the ‘Canon’ of the ‘Doctrine of Method’, the first section states the reason, whose unfolding elevates the third, motivational cosmopolitanism to a teleological one: the ‘final goal’ of reason, the final purpose that goes beyond the simple aim of an epistemic peace, is connected to three objects where our theoretical interest is slight, yet out moral-practical interest is all the more substantial: the freedom of the will, the immortality of the soul and the existence of God (CopR, B, 826).

The Critique of Pure Reason begins with epistemic cosmopolitanism; thematically, this comes first, and only then does it move on to the thematically second (i.e., moral) cosmopolitanism. The reason for this is that the second cosmopolitanism requires the insights of the first, such as the insights into the synthetic a priori, the difference between the receptive elements of perception, the spontaneous elements of the understanding and the genuine elements of reason, and, last but not least, the alleged conflict between nature and freedom, dealt with in the third antinomy. The Critique of Practical Reason likewise presupposes these insights.

The link that leads from the world of knowledge to the world of morality is the idea of the final end. Now, within epistemic cosmopolitanism, this increases its cosmo-political character. For, without the final end, the cognising subject is not yet cosmopolitan, but only, as Kant would say (see Chapter 4, 4.4 of this volume), a cosmo-theoros: despite the Copernican Revolution, he is a mere observer of the cosmos, and as such is set against and just watching it. Only viewed from the final end, qua moral subject, does he become a member of the cosmos, even its co-player (i.e., a subject in the fullest sense). This status (that of a responsible person) and not merely the ability to transcend national borders, or even the reality of global political institutions, elevates a man or woman to the status of a cosmopolitan person.

In the lecture notes Metaphysics of Morals (Vigilantius), Kant gives the philosopher of the ‘school’ a Greek title that I did not know from the published writings and that is so obscure that even an authoritative Greek lexicon, the Liddell-Scott-Jones, does not list it. Kant presumably took the neologism from Christian Huygens’s eponymous work (1698): anyone who deals ‘with nature in theoretical contemplation only with regard to the knowledge to be increased’ is called a ‘cosmotheoros’, according to the opus postumum in German ‘Weltbeschauer’ (Opus postumum, XXI, 553), which Kant contrasts with the ‘cosmopolite’.

With the term ‘cosmopolite’, Kant does not refer to a highly educated, worldly wise and urbane person, but to someone who ‘regards nature around him in a practical regard for the exercise of his benevolence towards it’ (XXVII, vol. 2.1, 673). In contrast to the cosmotheoros, who is interested in knowledge only, the cosmopolite is characterised by a moral-practical attitude. Once again, it is not the existence of political institutions that makes the difference, but the fact that human beings are persons in the demanding sense that in a relevant passage of the Opus postumum Kant explains as a ‘moral being’. The passage reads: ‘man as (cosmopolita) a person (moral being) conscious of his freedom (inhabitant of the world)’ (Opus postumum, XXI, 31, Section 9). On the other hand, the ‘cosmotheoros himself creates the elements of the a priori knowledge of the world from which he constructs the contemplation of the world as an inhabitant of the world in the idea’ (Opus postumum, XXI, 31, Section 9).

Kant’s understanding of and criterion for morality, the categorical imperative, known the world over and acknowledged by many moral philosophers, elevates the thematically second moral cosmopolitanism to the principle of action. In doing so, Kant practices, thirdly, a methodological cosmopolitanism. With its help, he contradicts radical ethical relativism that casts doubt on the possibility of a universally valid morality, while at the same time following the formal political accentuation of his cosmopolitanism. He introduces, albeit not quite as artfully as in the first Critique, the until now competing positions and overcomes the natural state of moral philosophy, which is thereby alluded to, in favour of the state of law of moral philosophy. The pertinent principle, the moral law or categorical imperative, famously demands that the rules of life – its maxims – can be universalised, and this applies to all people of every culture, even to living beings outside of humanity and capable of agency. Thus, for capacity to be rendered universal, like the synthetic a priori principles of the first Critique, is truly cosmopolitan: for the object in question, morality, comprises not only our species, but the entire world.

The following interim result suggests itself: obviously, today, in a time of globalisation, a cosmopolitan philosophy is highly welcome. Where