How is the practical deduction possible?

. In the Critique of Pure Reason , Immanuel Kant asserts the impossibility of the principles of practical reason, as “the objective reality of the moral law cannot be proved by any deduction” ( KpV , АА 05: 47). This is the case if deduction is understood as the procedure Kant follows in the “Transcendental Analytic” of the first Critique . Yet, Kant himself points out that “ deduction […] is the justification ( Rechtfertigung ) of its objective and universal validity” ( KpV , AA 5:46). This justification of the principles of practical reason can be found in Kant’s works and has a certain structure. Firstly, in the Critique of Pure Reason, he justifies the existence of an intelligible world where the determining ground of causality is freedom. In the intelligible domain, the principles of pure reason possess objective reality. Thus, in the first Critique , Kant justifies the existence of (i) an intelligible world, (ii) freedom as the ground of causality and (iii) the ought as a reason for practical action. Secondly, in the Groundwork of the Metaphysics of Morals , Kant demonstrates that freedom carries one to an intelligible world where the good will resides. The good will rests upon freedom and brings forth human autonomy. And it is the good will from which the categorical imperative and morality in general emanate. Thirdly, it is explicated in the second Critique that freedom is the keystone ( Schlußstein ) of practical reason. Here, the moral law (= “a fact of reason”) is instrumental in deducing transcendental freedom itself. This means that the reality of transcendental freedom manifests itself through the moral law. The moral law exists and is effective; therefore, there is transcendental freedom behind it. Thus, the structure of transcendental deduction of practical reason consists of the successive justification of (i) the intelligible world, (ii) freedom, (iii) the good will, (iv) duty (categorical imperative), (v) the moral law as a “fact of reason”. Consequently, the practical deduction is possible only through a synthetic union between the Copernican Revolution, transcendental idealism and criticism.


Introduction
The problem formulated as a question in the title of this article (How is the deduction of practical reason possible?) is not contrived: Kant himself made it unambiguously clear in the 1 In §4 of the 1770 treatise De mundi sensibilis atque intelligibilis forma et principiis, Kant avers that what is sensuously thought is the representation of things as they appear, while the intellectual presentations are the representations of things as they are. Fragments A 258 of the first edition and B 314 of the second of the Critique of Pure Reason, to which Schmitz refers, state that the understanding represents objects as they are. Thus, the above statement should be understood not in a transcendental but a merely empirical sense. In other words, objects can be represented in the thoroughgoing connection of appearances as objects of experience but not as things in themselves.
, 01004 (2023) t h   of theoretical reason, with profound changes occurring in all principal areas of the eighteenthcentury philosophy. If, focusing solely on the Critique of Pure Reason, we ask Schmitz's sacrosanct question "What did Kant want?", we will get the following answers (here, I will have to dwell on wellknown matters).
(i) Kant attempted to conduct a far-reaching reform of metaphysics or, to be precise, to assist with its new birth according to an earlier unknown plan. The limited reforms of "highly prized knowledge that is indispensable to humanity" (Prol, AA 04: 261; Kant, 2004, p. 11) undertaken by Erhard Weigel and, to a degree, Christian Thomasius, Ehrenfried Walther von Tschirnhaus, Christian Wolff, Christian August Crusius and many a Wolffian could not satisfy Kant. His objections to metaphysics could be overcome by elucidating and systematising concepts, unifying the structure of metaphysics and producing other trivial changes. Kant wanted to answer the questions as to whether metaphysics could tread the path of science as mathematics and natural science had done; whether metaphysics was possible in this way; what its sources, scope and boundaries were. Put differently, he undertook an extensive and far-reaching critique, i.e. research into reason. 2 (ii) The previous intention entails a further objective -that of outlining the possibilities, cognitive tools, action mechanisms and boundaries of the understanding and theoretical reason. This raises another fundamental question: how are pure a priori concepts possible? And this objective, in its turn, necessitates the transcendental deduction of pure concepts of the understanding.
(iii) Complications associated with deduction have lent urgency to Kant's old pre-critical idea about reform of formal logic. Since general logic cannot analyse the content of statements and thus hinders transcendental deduction, he provides a rationale for a new, content-focused, type of logic, i.e. transcendental logic.
(iv) Theoretical deduction limits the use of the understanding to the confines of experience. Hence, Kant arrives at the conclusion that we can cognise phenomena only, but not things in themselves. Consequently, "if things in themselves are substances, each of which has a nature and existence that is independent of others, then things in themselves, and not phenomena, are the most fundamental existents. The physical world is a dependent world; things in themselves are independent. Kant thus thinks that the most fundamental existents are not physical" (Langton, 2007, p. 207). This philosophical attitude is conventionally called criticism. The thing in itself, however, is the keystone of transcendental philosophy as a whole! This circumstance, in turn, questions the legitimacy of cognising (in its strict sense) the realm of the unconditioned. The latter is of vital importance since the way it is justified affects the fundamental domains of human life, such as morality and religion! Naturally, Kant could not allow any (even theoretical) infringement of the universal human concerns -first of all, morality and religion. Thus, the need arose to lodge a protest against materialism, atheism, fanaticism and superstitions, idealism and scepticism. Finally, this compelled a division of the entire human existence into (i) the world of natural necessity (and cognition) and (ii) the moral world of freedom. In other words, it was imperative "to deny knowledge in order to make room for faith") (KrV, B XXX; Kant, 1998, p. 117).
(v) Since the principal aim of transcendental philosophy was to protect freedom and, therefore, the entire practical domain, Kant began to analyse and justify speculative reason. In the "Transcendental Dialectic" Kant resolves antinomies and paralogisms, paying attention to the deduction of ideas of reason, including the fateful deduction of the idea of transcendental freedom. To reiterate: the search for the idea of transcendental freedom "has nothing whatsoever to do with the transition from theoretical to practical philosophy since, as was clear from the outset, the transition can only occur from practical to theoretical philosophy. Therefore, we are looking for a theoretical idea of reason extending to the domain of practical philosophy and permeating it because the former is already rooted in the latter" (Teichner, 1978, p. 73). Thus, the idea of transcendental freedom, just like the practical freedom, underpins the deduction of theoretical reason and practical reason.
These are some of the most fundamental intentions Kant explicates in the first Critique alone. Consequently, the justification of practical reason is essentially the central theme of transcendental philosophy as a whole.

The Structure of Transcendental Freedom Deduction
Since Kant sees the problem of justification of freedom as the principal aim of transcendental philosophy as a whole, this topic permeates all his major writings. Exploring the structure of deduction will notably reveal that various works of Kant have a distinct role in the justification of transcendental and practical freedom, as well as practical reason. Let us now consider chronologically the stages of deduction as seen in Kant's major works.

Critique of Pure Reason
As is well known, the first Critique covers -in an abridged or expanded form -almost all the problems that occupied Kant during his philosophical life. In that work, Kant addresses the idea of freedom already in the "Preface" (to the second edition).
A) Preface. One should remember that the Preface was written by Kant last, after completing the text of the second edition. Therefore, the Preface deals with the capacity to think of (rather than cognise) freedom as a thing in itself.
The human soul possesses free will because, as a thing in itself, the former does not belong to the world of phenomena and is not subject to the law of causality according to nature. Thus, freedom does not exist without the thing in itself. Here, Kant does not yet speak about practical freedom, which (as he will point out later) differs from transcendental freedom. We will come across such a division in the main text of the Critique. For now, Kant explains the general principles of his metaphysics, namely that transcendental freedom belongs to the realm of thinking, the domain of things in themselves: "the use of reason itself is freedom" (Refl 5613, AA 18: 254; Kant, 2005, p. 253).
B) About Ideas in General. Ideas of reason think of the unconditioned, in contrast to the conditioned residing in the domain of cognition, in which they have a regulative function only and require a systematic unity of knowledge. In the practical domain, reason is constitutive because it uses transcendental ideas, by means of which -to put it in modern terms -the whole of social life is constructed. And ideas are values too. Social reality is built on the basis of social values (in the broad sense). Under the ideas with which metaphysics is concerned, Kant classifies the idea of freedom (along with those of God and the immortality of the soul).
C) The Third Antinomy of Pure Reason. In the third antinomy, transcendental philosophy ultimately lays down and justifies the above-mentioned fundamental principle. Since it is impossible to acknowledge the existence of a single causality -causality from the laws of nature (for it contradicts the very definition of physical causality), there is a need for a causality not conditioned by nature, namely, that through freedom. The transcendental idea of freedom expresses the absolute spontaneity of practical action. The free action, therefore, represents a combination of consecutive states of efficient causes, which renders a unity of experience characteristic of natural causality impossible. Put simply, only thinking is the , 01004 (2023) t h   cause of the free will and free action. The free will is capable of initiating independently a series of events or states. Jens Timmermann (2003, p. 116) interprets this complex situation as follows: "Philosophy is meant to guarantee the compatibility of the idea of reason and concept of the understanding. If this project of a balance between freedom and nature fails, the antithesis 3 will be in a stronger position thanks to the support it receives from empiricism; the clams of the practical domain will have to be rejected as misleading. But Kant hopes that it will never come to that." D) On the Dialectical Inferences of Pure Reason. In this section (paragraph "Resolution of the cosmological idea of the totality of the derivation of occurrences in the world from their causes"), Kant performs a comprehensive deduction of freedom. And this is where the connection between freedom and obligation (duty) appears for the first time. Thus, the transcendental deduction of practical reason can be traced to this point for "[e]verything is practical that is possible through freedom" (KrV, A 800 / В 828; Kant, 1998, p. 674).
Thus there are two types of causality: according to nature and from freedom. Causality from necessity is always linked to time. It is part of a time series and thus necessary.
Causality from freedom is rooted in the idea of spontaneity, which is capable, on its own, of initiating a series of events. This is the essence of the transcendental idea of freedom. In schematic terms, freedom is spontaneity. And this transcendental idea underpins that of practical freedom, which is, in the first place, independence from compulsion to sensibility. Although humans cannot escape the influence of sensibility, they can determine their actions. In this vein, Paul Guyer underscores the difference between transcendental and practical freedom: "So transcendental freedom and practical freedom, that is, freedom of the will and autonomy, are not identical. Rather, autonomy must be conceived of as a condition of mastery over our inclinations in our choice of ends and actions, and for that reason as a condition of cooperation with, but not domination by, others as well, a condition which we can freely choose to maintain, but which we can just as well freely choose to subvert. Autonomy is not identical to a noumenal 'act' of freedom. Autonomy is a condition, dependent upon an a priori principle but realized in the empirical world, which we can freely choose to realize and maintain, or to subvert or destroy" (Guyer, 2005, pp. 125-126). This means that humans freely determine their practical actions. Yet, they are exposed to the influences of both sensibility and the ideas of reason (values). Interests (including needs) are often conditioned by values (ideas of reason) and culture in general.
Whilst the deduction of practical freedom does not seem to pose any serious problems to Kant, the idea of transcendental freedom "constitutes the real moment of the difficulties" (KrV, A 533 / В 561; Kant, 1998, p. 533). What is to be done here?
Kant writes: " [I]f appearances are things in themselves, then freedom cannot be saved" (KrV, A 536 / В 564; Kant, 1998, p. 535). For, in this case, all causes belong to the domain of nature. Consequently, the key to the deduction of freedom (and hence the deduction of practical reason as a whole) lies within the concept and tenets of transcendental idealism.
If phenomena are representations, the former must have grounds that are not phenomena. And such a ground is the transcendental object. The transcendental object possesses causality, which is not a phenomenon per se, although its result is found in a phenomenon. Subjects of sensible intuition, in their turn, have an empirical character on the one hand, and an intelligible one on the other.
Intelligible subjects are not bound by the temporal condition and the influence of sensibility. Kant calls them noumena. As we remember, in its negative meaning and this meaning only, a noumenon is a thing that is not an object of sensible intuitions. The noumenon is a problematic concept whose function is to delineate the realm of sensible 3 That is the antithesis of the third antinomy of pure reason: "[t]here is no freedom, but everything in the world happens solely in accordance with laws of nature" (KrV, A 445 / B 473; Kant, 1998, p. 485). intuitions and prevent the domain of cognition from encroaching onto that of things in themselves. The function of the noumenon is demarcation. Such a noumenon, Kant emphasises, is the pure "active being" (tätige Wesen) (KrV, A 541 / B 569; Kant, 1998, p. 537) which, when acting, does not depend on natural necessity. A noumenon independently initiates the action of its cause in the sensibly perceived world, but this action begins elsewhere. In other words, the causality of actions performed by a noumenon lies in the intelligible domain. Yet, being real, this action occurs externally in the sensibly perceived world and appears as if dealing with a long sequence of causes and actions. Moreover, Kant asserts, "practical freedom can be proved through experience" (KrV, A 802 / B 830; Kant, 1998, p. 675). Specifically, we "cognize practical freedom through experience, as one of the natural causes, namely a causality of reason in the determination of the will" (KrV, A 803 / B 831; Kant, 1998, p. 676).
A necessity of a special kind emerges as a consequence. Since noumenal causality is found in reason rather than nature, intelligible causality produces the necessity of action of a particular type. When our actions are based on natural reasons, the will (das Wollen), i.e. a wish, a desire conditioned by sensible interests, arises. But when the cause of action is in the noumenal domain (this can be an idea of reason: the idea of justice, good or benevolence), we are faced with a necessity of a different kind -the ought (das Sollen) (KrV, A 548 / B 576; Kant, 1998, p. 541).
The ought in an intelligible world is an entirely different reason from the will in the sensibly perceived one. (The will: I want to eat something. The ought: I must help the person in distress. In which reason is freedom found?) The ought (das Sollen) proclaimed by reason, has -unlike a common sensible -authority or the ability to forbid, in other words, coercive power. Since, in the intelligible domain, reason has causality in relation to phenomena, it can be the determining cause of our actions, which have already been rendered free. Although human beings themselves are phenomena, reason is not one, nor is it sensibly conditioned. But, conversely, it determines through causality the actions of humans in the sensibly perceived world: "reason is thus the persisting condition of all voluntary actions under which the human being appears" (KrV, A 553 / B 581; Kant, 1998, p. 543). And this is the foremost conclusion of the entire deduction of freedom.
Based on the causality of reason, such freedom can be both negative, i.e. independent of sensibility, and positive -construed as an ability to initiate independently a series of events. Therefore "in freedom a relation is possible to conditions of a kind entirely different from those in natural necessity, the law of the latter does not affect the former; hence each is independent of the other, and can take place without being disturbed by the other" (KrV, A 557 / B 585; Kant, 1998, p. 545). 4 Е) On the Ideal of the Highest Good. Kant famously infers from the above intelligible reality and rationality: the principle of pure reason has objective reality in its practical and, in particular, moral use: "I call the world as it would be if it were in conformity with all moral laws (as it can be in accordance with the freedom of rational beings and should be in accordance with the necessary laws of morality) a moral world. This is conceived thus far merely as an intelligible world since abstraction is made therein from all conditions (ends) and even from all hindrances to morality in it (weakness or impurity of human nature). Thus far it is therefore a mere, yet practical, idea, which really can and should have its influence on the sensible world, in order to make it agree as far as possible with this idea. The idea of a moral world thus has objective reality, not as if it pertained to an object of an intelligible intuition (for we cannot even think of such a thing), but as pertaining to the sensible world, although as an object of pure reason in its practical use and a corpus mysticum of the rational beings in it, insofar as their free choice under moral laws has thoroughgoing systematic unity in itself as well as with the freedom of everyone else" (KrV, A 808 / B 836; Kant, 1998, pp. 678-679).
Although the deduction of transcendental freedom in the first Critique was successfully completed, the idea itself remained problematic. Freedom requires, one might say, some "oncoming traffic" from the moral (practical) world. Only this mutually beneficial movement can justify the objective significance of practical reason and thus the moral world.

Groundwork of the Metaphysics of Morals
In this work, Kant turns to the very foundations of practical reason, namely the metaphysics of morals. Before proceeding to examine the critique of pure practical reason, it is essential to locate the "transition" from transcendental freedom to practical reason and the moral law.
This link, in fact, is the supreme principle of morality (GMS, AA 04: 392; Kant, 2006, p. 5), which can be found if our reasoning proceeds from the good will. Morality as such is the relationship between an action and practical law. The presence of law in a person may produce a situation where the individual good will could see itself as enacting universal laws. And this is where the ought emerges, which, as we remember, ensues from the idea of freedom.
Based on this, Kant devises the first formulation of the categorical imperative: "act only in accordance with that maxim through which you can at the same time will that it become a universal law" (GMS, AA 04: 421; Kant, 2006, p. 31). To achieve this, a good will must be autonomous (i.e. a law for itself) and have a ground of its own. And this ground has to be deduced.
If the will (as an ability to determine actions according to law) is a kind of causality distinctive of rational beings performing practical actions, transcendental freedom is the foundation of the will itself. Kant attempts to deduce freedom from pure practical reason. But transcendental freedom itself as a type of causality is, in its turn, another means to justify practical reason, since it points directly to a special (intelligible) world in which it exists. Reason generates its own principles when it is free. But if reason is free, it makes laws for itself. And here we find the source of the required oncoming traffic of freedom and the moral world. It turns out that freedom, self-legislation of the will, autonomy and law are interchangeable concepts (GMS, AA 04: 450; Kant, 2006, p. 55). This interchangeability raises a further problem: we cannot use these terms to explain each other. Therefore, there is a need for access to the intelligible world.

Critique of Practical Reason
Freedom is the Schlußstein of practical reason and the moral law (imperative). The moral law, which is a "fact of reason" serves now for the deduction of transcendental freedom. At the same time, we must keep in mind that, despite being able to perceive empirically the consequences of the existence of the moral law and despite Kant calling this law a "fact", the moral law is neither an empirical phenomenon nor an empirical fact: it is a fact of pure reason (Faktum der reinen Vernunft) (KpV, AA 05: 47; Kant 2015, 41), i.e. an intelligible fact and law governing the moral world as a set of values and the world of practical (moral) action. 5 Here, however, we confront the problem described by Béatrice Longuenesse (2005, p. 237): "[…] the fundamental difficulty we encounter in attempting to think the relation between the moral law (which depends on the faculty of reason alone, and thus on our belonging to a purely intelligible world) and actions that unfold in the sensible world and are thus causally necessitated. This metaphysical difficulty is according to Kant the root of the difficulty of moral judgment, evaluating an action or the will of the subject that performs that action (is it a good will or not?). For an external event, given in space and time, does not by itself give us any access to the internal motivation of the agent (did she act from respect for the moral law, or on the contrary from egoistic interest?)" Moral law determines the law for causality. In other words, it serves as the deduction principle for the "faculty of freedom, of which the moral law, which itself has no need of justifying grounds, proves not only the possibility but the reality in beings who cognize this law as binding upon them" (KpV, AA 05: 47; Kant, 2015, p. 41). The reality of transcendental freedom manifests itself (is explicated) exactly through moral law: since moral law exists and is effective (and we are witnessing such real actions), there is transcendental freedom behind it, and this transcendental freedom is the causality of actions carried out under the immediate influence of the moral imperative.
Thus, this mutually conditioned deduction is, on the one hand, a means to curb the claims of theoretical and practical reason. Practical reason must be kept in check as regards its conceited desire to be the only determining ground of the will. On the other hand, mutually conditioned deduction endeavours to solve the immensely complex problem of the logical and, particularly, transcendental deduction of extremely general concepts (universals). Kant emphasised in the Groundwork of the Metaphysics of Morals that both modes of deduction, theoretical and practical, are necessarily linked and mutually conditioned for they deal with "one and the same reason, which must be distinguished merely in its application" (GMS, АА 04: 391; Kant, 2006, p. 5).

The fundamental problem of the two modes of deduction
A substantial problem with both types of deduction is, it seems, the two being built on the so-called "transcendental argument", whose central function (speaking in general terms) is to determine the conditions of cognitive activity. Researchers have differently described the essence of the "transcendental argument". For instance, the advocates of the analytical approach to deduction (e.g. Peter Strawson) believe that transcendental arguments take on the logical form of modus ponens: (1) Experience exists (type A).
Premise (2) must be an analytically true statement. The conclusion would be synthetic a priori only if premise (1) were also synthetic a priori (Grundmann, 2003, p. 52).
It seems the principal characteristic of the "transcendental argument" is using the form of incorrect conditional-categorical inference.
The classical correct modus ponens looks as follows: that freedom constitutes the 'keystone' of his system. The notion of a Kantian 'keystone' that is called a 'fact' may seem to be more than perplexing, but there is a fairly simple explanation that can be given of at least Kant's terminology here. The 'fact of reason' is said to be a 'fact' because it is not derived from something prior to it. At the same time, it is 'of reason' because it is understood to be given to us not through contingencies of feeling but from part of our general and essential, albeit not merely theoretical, character as rational agents." p → q, p therefore, q.
This modus is correct all round: it proceeds from affirming the truth of the antecedent to affirming the truth of the consequent. The conclusion in such inference follows necessarily.
Kant's transcendental argument is constructed differently -from affirming the truth of the consequence to affirming the truth of the antecedent. He argues that phenomenon q has necessary condition p.
In terms of formal logic, this is incorrect conditional-categorical inference since the cause of q can be both p and non-p. In other words, the conclusion does not follow necessarily.
In Kant's work, it goes as follows: А. In the deduction of pure concepts of the understanding: (1) If there are pure a priori concepts, experience is possible.
(2) Experience is possible. Therefore, there are pure a priori concepts of the understanding.
В. In practical deduction: (1) If there is transcendental freedom and the a priori moral law, moral actions are possible.
(2) There are moral actions in our life. Therefore, there are transcendental freedom and the a priori moral law.
I believe that Kant is right: this is how it actually is. Nevertheless, formal logic cannot prove the truth of these incorrect inferences since their form is compromised. There is only one way out: disregarding the form of the inference and analysing the content. Content analysis can show whether the incorrect inference is true or false. Yet it is impossible to analyse the content of inference within the boundaries of formal logic. That is why Kant, just like many of his predecessors, builds a content-focused logic, calling it transcendental. Indeed, transcendental logic is perfectly capable of exploring the content-related aspects of phenomena and processes and thus proving the truth and necessity of the inference of such incorrect conclusions. Put differently, analysing the content of the actual state of affairs can show that p is the cause of q (i.e. prove the necessity of the existence of p and affirm the causal status of p).
Consequently, transcendental (content-focused), not formal, logic is necessary for Kant. According to him, transcendental logic can use content analysis to support the claim of the objective significance of a priori concepts of the understanding, moral law and the idea of transcendental freedom.
The two types of deduction help each other out. Kant clearly argues that the deduction of categories would be necessary and beneficial for theology and morality. Since theoretical deduction has demonstrated that concepts of the understanding a) do not have an empirical origin and b) belong to objects in general, independent of intuitions, it has restricted the speculative use of reason and averted the danger of considering concepts as innate or, on the contrary, strictly empirical. Therefore, theoretical deduction has managed to justify the transcendental cognition of things and the existence of an intelligible world of freedom and morality.
Besides this "problematic" similarity betraying the internal kinship of the two types of deduction, there are indisputable differences between them. They are, however, a topic for another study.

Conclusion
So how is practical deduction possible?
The justification (= deduction) of practical and theoretical reason is possible if the Copernican revolution in metaphysics is performed, and the traditional objects of metaphysics change as a result. In the theoretical domain, we no longer follow slavishly some object but study the cognitive abilities of agents actively investigating the world. And we reveal simultaneously that space and time are forms of sensible perception (i.e. what is called transcendental idealism), whilst the understanding uses senses to synthesise independently the object of cognition. This synthesised object is a mere phenomenon and not a thing in itself (= criticism). Yet, it is impossible to manage without a thing in itself.
In the practical domain, we conduct a similar "revolution" by focusing attention on the realm of the social (= culture as Bildung) and establish that, besides the physical world of nature, there is the intelligible world of transcendental freedom.
In this intelligible world, we find transcendental freedom, which acts as the free good will and makes our practical freedom possible as the autonomy of rational beings. The causality from freedom brings to life a new reason for rational beings to act. This reason is duty, which points directly to the a priori moral law. The moral law, in its turn, as a "fact of pure reason", serves as the ground of transcendental freedom. This way, deduction comes full circle. This is not, however, the vicious circle of bad infinity, but a fecund and mutually conditioned principle of transcendental freedom.