INTRODUCTION
Between Two Worlds: Critical Constructivism After Kant

Reason thus refers every maxim of the will as universally legislating to every other will [...], and it does so not for the sake of any other practical motivating ground or future advantage, but from the idea of the dignity of a rational being that obeys no law other than that which at the same time it itself gives.1

Now in this way a world of rational beings (mundus intelligibilis) as a kingdom of ends is possible, and possible through their own legislation of all persons as members.2

The idea of a constitution in harmony with the natural right of human beings, one namely in which the citizens obedient to the law, besides being united, ought also to be legislative, lies at the basis of all political forms; and the body politic which, conceived in conformity to it by virtue of pure concepts of reason, signifies a Platonic ideal (respublica noumenon), is not an empty figment of the brain, but rather the eternal norm for all civil organization in general, and averts all war.3

1 The idea of Kantian constructivism

Kant's words seem to lead us into the depths (or shallows) of his metaphysics of two worlds - the one intellectual-noumenal, the other empirical - and thus to land us in all of the problems associated with this dualism. Far from wishing to trivialize these problems, I want to propose a different perspective on these questions after Kant, or rather two such perspectives: according to the first, there is a sense in which we cannot escape such dualisms in our moral and political practice; according to the second, this dualism loses the appearance of an aporetic metaphysical problem once we understand the world we live in in the correct pragmatist sense, that is, reasonably.

Let me begin with the first of these perspectives. Anyone who takes seriously the statements to be found in human rights declarations to the effect that "All human beings are born free and equal in dignity and rights" (Article 1 of the Universal Declaration of Human Rights of 1948) and that this dignity is "inviolable" (Article 1[1] of the German Basic Law of 1949), rather than dismissing them as ideological or utopian platitudes, must be able to explain the sense in which these propositions are true. They do not describe the empirical reality, since it is simply not true that all people are born in equal, inviolable dignity and with equal rights - rather, many of them grow up in conditions of extreme inequality, dependency and ignominy, from which they can hardly escape. This analysis is factually true. But can both truths hold simultaneously - that of the normative statement and that of the social reality? They must, for otherwise we could not adopt a justified critical stance on reality - and we might even be betraying those whose human rights are trampled underfoot.

The philosophical discussion about how such counterfactual normative statements can be justified is indeed interminable; but that they require a justification seems indisputable. This provides the point of departure for my interpretation and further development of Kant. When we raise the question of a justification for the normative status of dignity, it may be helpful to reflect on ourselves as the beings who pose this question and who owe each other an answer. For we not only ask for reasons, but also use, evaluate and justify reasons. And, where we must acknowledge that there are no good reasons for denying others equal respect, we show ourselves and them respect as justifying beings, as equal normative authorities who owe each other good reasons for how they treat one another and for the normative order to which they are subject. Then the status of equal dignity is not justified based on an empirical proof or a divine norm, which would in any case be impossible, but through rational recognition of ourselves and others as justifying beings, as authorities in the space of justifications who form a community of justification.4 In Kant's terms, this implies the mutual respect of persons as self-determined purposive ends in themselves, as legislating members in the "kingdom of ends," a status that constitutes their "worthiness" (Würdigkeit).5 Is there any better justification of this dignity than being an autonomous member of the "law-giving" community regarding the norms that should apply to all?6 That this reflection, specifically in virtue of the emphasis it places on the equal status of being a lawmaking member in the space of justifications, is unavoidably a form of moral reflection Kant explains by the fact that, as justifying beings who ask the practical question "What should I do?," we are already operating as responsible subjects in the space of practical reason. Here there is no escape, for our world is the world of justifications. However, we are not simply subject to it, but should understand ourselves in it - and this is Kant's revolutionary insight - in a counterfactual sense as legislative authorities.7

Turning now to the second perspective: What kind of world is this, the world of justifications? Let us assume in a realistic, pragmatic spirit that our world of action is indeed a world of justifications that guide our thought and action. Then these are, first of all, de facto valid justifications that can be quite diverse in nature: conventional, instrumental, religious, legal, well or poorly considered, blinded by ideology, and so on. This is in fact the empirical-noumenal substance, so to speak, from which we draw the justificatory material for our action; the normative orders within which we operate are, in this factual sense, "orders of justification." But, if we understand ourselves as beings endowed with practical reason, it is not only a matter of acting rationally and prudently in these already established justificatory spaces. We can also ask whether they are reasonable, and this includes asking whether they are morally reasonable - that is, justifiable on moral grounds. In every human practice, however congealed it may be with ideology (where "ideology" means justifying the unjustifiable), one always has the possibility, even if only slight, of asking: Are these norms, customs and traditions, these laws and ordinances, this ruling order as a whole, justified? In accordance with which criteria should this be evaluated?

Where this critical question arises, it may be stifled de facto in the space of noumenal power. However, it can be raised over and over again, and morally speaking it must be raised for the sake of the justifiability of our actions and of the structures that guide and bind us. To rise above the existing space of justifications, perhaps initially to a limited and subsequently a greater extent, is part of the human practice of justification when this is not completely obstructed, which means that humans, as participants in this practice, are potentially noumenal beings who transcend the reality they encounter. Kant's reflection on humans as legislating beings who enjoy equal status in the realm of ends, and are obliged to offer each other reasons that are uniformly generalizable, is in my view the appropriate reflection on our situation as justifying, transcending beings in this sense. We belong to the factual world of justifications, but we are also members of a realm of critical problematization and of mutual respect that binds us here and now and places a duty on us to offer justifications in moral or political contexts. The kingdom of ends - properly understood - is of this world. We must not succumb to the misconception that we are members of two strictly separate worlds, nor to ontological or metaphysical dualism, but must recognize that we would not be able to orient ourselves reasonably in this one world if we could not question and transcend the given justifications. In other words, the counterfactual question concerning better justifications is part of the facticity of our normative world of justification. The worlds in question, the noumenal and the empirical, are therefore not really two separate worlds, but two different perspectives on ourselves as subjects of justification. Thus, the counterfactual, transcending-noumenal normativity of self-determined legislation appears within the de facto normativity of our empirical-noumenal spaces of justification - as a prefiguration of genuine individual and collective autonomy.

What does asking for reasons in this transcending sense involve and what kind of validity can the corresponding answers claim? This is where what I call "critical constructivism after Kant" comes into play and, since I discuss this in previous works8 and in the chapters in this volume, I will confine myself here to the main lines of argument. If we formulate the question concerning the reason-giving transcending of given justifications in transcendental terms, then it concerns the conditions of the possibility of justifying valid norms of responsible action (or of political rule). Evidently, this transcendental reflection does not detach itself from human practice so much that it loses its connection to the latter; rather, the question of justification is as much an imminent as a transcending one. It refers to the faculty that is the sole faculty...