German Classical Philosophy

The Critical Philosophy of I. Kant

Critique of Pure Reason

In the title of the work, the term "critique" is used in its original sense of "investigation," devoid of the negative connotation it carries today when evaluating a particular idea or position. As for the phrase "pure reason," Kant sought to emphasize that the investigation pertains to the activity of reason in which it produces a priori knowledge (knowledge that precedes experience). Thus, reason is the faculty of a priori cognition.

Kant's strategic aim during this critical period was to reform philosophy by drawing upon the transformative experiences of the natural sciences. Where disorder and chaos had previously been perceived, Newton introduced strict order, establishing science by organizing natural knowledge according to specific principles. These principles were of an a priori nature; however, the material to which they were "applied" was empirical, derived from experience.

Kant distinguished between science in its proper and improper senses. Only the former could claim the title of true science, as its judgments possess an irrefutable, absolutely true (apodictic) character, ensured by mathematics. "I assert," Kant wrote, "that in any particular discipline concerning nature, one can find genuine science in its proper sense only to the extent that it includes mathematics." For it is precisely mathematical propositions, as examples of a priori judgments, that grant science its theoretical character.

Yet the time had come to reform philosophy according to this model, particularly its principal segment—metaphysics. "It is inevitably expected," Kant was convinced, "that there will be a complete reform, or rather, a rebirth of metaphysics according to a completely unknown plan thus far." The old metaphysics had reached an impasse, lagging behind the natural sciences. It was dominated by a rationalistic-dogmatic method that unwarrantedly claimed to engage in "scientific" inquiry into super-sensible matters derived solely from reason (which had no empirical foundation).

Kant was confident that humans possess a priori forms of knowledge, but he pondered how to incorporate empirical information into philosophy, how to connect a priori forms of thought with empirical material, thereby distancing himself from outdated, moribund speculative systems and directing metaphysics towards the path of science.

To address this task, one must specify it, breaking it down into a sequence of particular objectives, establishing the order of their resolution. Kant laid out the path to his goal by first providing a step-by-step justification of answers to such questions as: how is pure mathematics possible, since it has already justified itself as one of the hallmarks of scientificity? How is pure natural science possible? How is metaphysics possible at all? Is metaphysics possible as a science? This is not yet the actual reform of philosophy nor the establishment of its system, but rather a kind of preliminary, propaedeutic work, the task of which is to clarify the overall possibility of philosophy achieving the status of science. Any other philosophical work must be deferred until these questions are resolved, and one should not expend futile efforts. In fact, this section addresses the investigation of the fundamental cognitive capacities of humans, examining the conditions and possibilities of knowledge. Only after this can one proceed to further work. This propaedeutic stage is what Kant termed critical philosophy, to which corresponds the critical or transcendental method.

"I call," the thinker wrote, "transcendental any knowledge that does not concern so much the objects as our way of knowing the objects, insofar as such knowledge must be possible a priori." The term "transcendental" is used here to characterize the conditions of possible experience that facilitate the transition to knowledge.

In substantive terms, science represents a collection of organized judgments, which can be either analytical or synthetic. The former have an explanatory character to the extent that the predicate does not introduce new knowledge but merely repeats what is already contained in the subject in another form. For instance, the judgment "All bodies are voluminous" is analytical because the property of being voluminous is already inherent in the concept of a body. It is analytical because it is derived from a simple unpacking of the predicate's content, not expanding our knowledge of the body. However, knowledge entails an increase in the volume of knowledge; this requirement corresponds to synthetic judgments. The assertion "Some bodies have weight" contains something in the predicate that is not found in the general concept of a body. This will be a synthetic judgment because it combines two concepts: "body" and "weight."

Kant further divides synthetic judgments into two classes: judgments of experience and a priori judgments. The former suffer from the lack of universality and necessity, and the fulfillment of these requirements is essential for a truly scientific judgment. Thus, it follows that genuine knowledge, the results of which differ in necessity and universality, consists of a priori synthetic judgments. An example of such judgments is found in mathematics. For instance, (7+5)=12 is a synthetic a priori judgment because the concept of the sum indicates only the operation that must be performed with the numbers, yet the number encompassing 7 and 5, that is, 12, is not yet conceived.

The essential characteristic of pure (non-applied) mathematical knowledge, which distinguishes it from other forms of a priori knowledge, is that it arises through the construction of concepts. According to Kant, to construct a concept means to make it "sensible," to translate it into intuition, in other words, to connect intuition with the concept. Anticipating further, we note that, unlike mathematics, pure philosophy is knowledge derived by reason solely through concepts, without the mediation of sensory observation.

Let us recall that Kant referred to pure knowledge as that which emerges from pure reason independent of any experience. Besides mathematics, a priori synthetic judgments are also inherent to natural science. Metaphysics too, at least in its aim, consists of such judgments.

Since the examples of mathematics, natural science, and metaphysics demonstrate the existence of a priori synthetic judgments, the question is then specified: how is a priori synthetic knowledge possible, and how is it accomplished?

The answer to this question begins with the observation: "There are two roots of human knowledge that may grow from a common yet unknown root, namely SENSIBILITY and understanding: through the former, objects are given to us, and through the latter, they are thought." In other words, sensibility provides data, and through the activity of understanding, concepts arise.

The sensory impressions of objects are sensations. If observation arises from sensation, it is termed empirical. The object of empirical observation is what Kant calls a phenomenon. That part of the phenomenon corresponding to sensations is its material, while that which organizes this material can be considered the form of the phenomenon. The forms of all phenomena exist in our "thought" as ready-made; they are a priori and can therefore be considered independently of any sensation. The pure form of sensibility, in which any sensations are absent, may also be referred to as pure observation. Kant examines the conditions and possibilities of our sensory cognitive capacity in the section "Transcendental Aesthetics" (the term "aesthetics" is used here in its original ancient Greek sense, relating to the Ukrainian "sensible"). The section devoted to the principles of pure thought is entitled "Transcendental Logic."

In "Transcendental Aesthetics," Kant demonstrates that the a priori forms of SENSIBILITY are space and time. The SENSATIONS that a person receives are observed by them through space and time, meaning they are organized and perceived as phenomena. The difficulties in Kant’s understanding of the nature of space and time arise from the desire to interpret them either as innate forms (when we align ourselves with Kant) or as objective external conditions for the existence of objects (when we wish to counter him). In truth, Kant would not agree with either interpretation. Space and time, as forms of sensibility, represent a certain subconscious activity of our spirit, prompted by external impressions. The very concepts of space and time arise only after we become aware of our initially subconscious activity of organizing sensations.

Kant posited that both concepts are acquired; they are abstracted not from sensory perceptions of objects, but from the intrinsic activity of our mind, which organizes sensory impressions according to stable laws. From this understanding of space and time, Kant concludes that a priori knowledge is possible. The transcendental aesthetics culminates in an important assertion: firstly, external objects are perceived not as they are in themselves, but as they appear through the union of sensations and a priori forms of sensibility; secondly, the a priori forms of observation (space and time) prove to be an essential part and condition of the cognitive process aimed at producing a priori synthetic judgments.

The transition to "Transcendental Logic" is connected with the consideration of knowledge as thought. This part of the work is divided into two sections: transcendental analytics and transcendental dialectics. Kant links the justification of the possibility of knowledge directly with the question of experience. The concept of experience in all of modern European philosophy is perhaps among the most significant and carries its specific meaning. One of the founders of empiricism, John Locke, asserted that all our knowledge begins with experience (to be understood as both external and internal perceptions) and did not posit any other source of knowledge.

Kant partially agrees with Locke. He adds that, besides empirical beginnings, there exists an a priori source of knowledge. Any experience, he explains, consists, firstly, of the observation by which the object is presented for knowledge, and secondly, of the concept by which it is thought. Separately, these types of representations do not provide a complete picture of knowledge. Thus, the presentation of things through experience lies in the combination of sensory observation and a priori concepts. Experience itself arises only because the perception is supplemented by the concept of the understanding, Kant contended.

It is also essential to note that experience, objects, and nature are somewhat identical. Experience is the combination of phenomenon and concept as the a priori form of understanding. The result of such a combination is nothing other than the object. The totality of objects, the objective world, is denoted by a single word—nature. Here, nature is not discussed as a thing in itself, but as an object that we come to know. Therefore, Kant asserts that experience (and we might add—objects, nature) is a form of knowledge.

The ability to think is the understanding. The first question that arises here is: what exactly is thought, what is the substance of thinking? What is thought are the "objects" of sensory observation. Thinking does not exist without either sensibility or understanding. "Thoughts without content are empty, and intuitions without concepts are blind," Kant summarizes. Let us recall the foundational problem posed by critical philosophy: how are synthetic judgments possible? Henceforth, special attention should be paid to two terms: "judgment" and "synthetic," as they have a direct relationship to the activity of the understanding. The understanding can generally be defined as the capacity to create judgments, and its activity consists precisely in the realization of this capacity.

In transcendental logic, Kant also narrows the investigation, highlighting only that part of thinking which has its source exclusively in the understanding, thus speaking of pure understanding. The origin of this relatively autonomous part is the spontaneity of knowledge. In other words, the understanding is capable of independently producing representations, albeit representations of a second order, for representations of the first order are provided to us by sensibility with its a priori forms. The first-order representations seemingly display their sensory diversity; however, the spontaneity of our thinking requires that this variety be somehow reviewed, perceived, and connected to yield knowledge. Kant calls this activity synthesis and attributes to it exceptional significance in the entire functioning of the understanding. The spontaneity of thought is based on the initial, dynamic readiness of the human soul for synthesis. Nevertheless, the function of reducing this synthesis to concept is carried out by the understanding itself. An a priori concept arises when the understanding captures within itself the activity concerning the "pure synthesis," that is, the very form of synthesizing activity.

Synthesis denotes combination, connection. "But the connection is not contained in the objects," Kant proclaims, "and cannot be borrowed from them through perception, only to then be accepted in the understanding; on the contrary, it is a function of the understanding, which itself is nothing more than the capacity a priori to connect." This notion, the philosopher designates as the highest foundational principle of all human knowledge; let us recall once again the "Copernican Revolution."

Thus, the result of synthesizing activity is, first and foremost, the concept. Among the rich palette of various concepts we employ, there are those created by the presence of observation, as well as pure or transcendental concepts. The former are empirical; the latter, a priori. For instance, when I perceive various types of trees in sensibility, I associate this diversity into a single concept of "tree." Such concepts, which themselves serve the creation of concepts, Kant calls categories; they are precisely the a priori forms of the understanding that serve as conditions for possible experience. In the "Critique of Pure Reason," Kant meticulously elucidated the exhaustive collection of all pure concepts (categories) of the understanding. There turned out to be twelve, forming four blocks.

1. Categories of quantity: unity, plurality, totality.
2. Categories of quality: reality, negation, limitation.
3. Categories of relation: substance and accident, causality and dependence (cause and effect), interaction (the relation between that which acts and that which is acted upon).
4. Categories of modality: possibility, existence, necessity.

The identified categories are pure concepts of synthesis; the understanding "holds them within itself" a priori and utilizes them to think and comprehend. As a result of retaining an interconnected collection of pure concepts, the subject preserves the representation of the world as stable, recognizes it as the same, and is aware of the unity of the world due to the presence within the subject of a primary unifying activity, expressed in the phrase "I think," or self-consciousness (in Kant's terms, "transcendental unity of apperception"). The original self-consciousness is a combination of our active self (I), which then expands to self-awareness of representations as my representations, which can be articulated in the formula "I is identical to I," that is, "I" is identical to the unity of all representations. It is worth noting that later, the second representative of German classical philosophy, namely J.G. Fichte, would adopt this formula as the starting point of his own concept (“Wissenschaftslehre”).

After Kant revealed the categories, he analyzed the elements of cognitive ability. These include the understanding itself, the capacity for judgment, and reason, corresponding to the procedures for creating concepts, judgments, and inferences. Collectively, they can be referred to as understanding in the broadest sense of the term. We shall not detail this aspect of Kant's studies; suffice it to say that the philosopher uniquely addressed the problem of the possibility of mathematics, natural science, and metaphysics. The synthetic judgments of mathematics rely on pure observations of space (geometry) and time (arithmetic). Natural science is based on experience, which combines the natural givenness of phenomena with the pure forms of thinking (understanding). Metaphysics is also possible, but only as a system of all principles of theoretical knowledge by means of concepts, or as a system of pure theoretical philosophy. This metaphysics pertains to the discovery of the conditions of possible experience. Yet, one more question remains, to which Kant prepares a negative answer: is metaphysics of the non-sensory possible?

In the "Critique of Pure Reason," a chapter is dedicated to transcendental dialectics. The realm of dialectics concerns the logic of "appearance" and "form," yet it is not the empirical appearance, such as when a spoon appears broken in a glass of water, but rather a transcendental visibility that draws us beyond the empirical application of categories, urging us to seek illusory goals. Kant seeks to clarify how such judgments arise, judgments that pull us beyond experience, prompting us to their hopeless use analogous to judgments of experience. These erroneous judgments are what the philosopher refers to as transcendental, corresponding to a transcendental object of judgment, meaning one that lacks a correlate in experience. To investigate the origins of transcendental judgments, Kant turns to the examination of reason itself, as a relatively autonomous instance of human cognitive activity.

In transcendental dialectics, Kant aims to explore reason as the producer of certain principles (general conditions) to achieve a higher unity of cognitive knowledge. It is for this reason that he emphasizes: "...here we distinguish reason from understanding by what we call reason as the capacity for [creating] principles." In this function, reason is never directed immediately towards experience or an object; it always deals with understanding, bestowing unity upon knowledge through reason. Understanding also creates unity concerning the manifold of observations through rules. However, understanding itself requires unity for its own harmony. Reason supplies understanding with higher principles to attain the desired unity. Clearly, these principles pertain not to objects, but rather serve as subjective laws governing that which possesses understanding.

The principles of reason are connected to its ideas, emerging from them. "By idea I mean," Kant explains, "such a necessary concept of reason for which there can be no adequate object given in the senses." In other words, the instance of reason does not create any concepts; ideas are categories of understanding expanded to such a form that they possess absolute completeness of empirical synthesis to the unconditional. The fact is that understanding (by the very nature of the logic of thought) always moves from one conditioned state to another, attempting to conclude this series with something final, absolutely unconditional. The unconditional is presented to us by reason in the form of ideas, which Kant categorizes into three classes:

1. The absolute unity of the thinking subject (the subject of psychology);
2. The absolute unity of the conditions of phenomena (the subject of cosmology);
3. The absolute unity of the conditions of all objects of thought (the subject of theology).

Thus, it ultimately follows that pure reason provides ideas of the soul, the world, and God. The idea of reason, on one hand, indicates the final instance of the sequential movement of knowledge from each successive conditioned state to the unconditional, in order to attain a complete concept of the object. On the other hand, it assigns a rule for how one should advance towards the unconditional, even though it is never fully attained. Ideas possess only a regulative use; they are like goals towards which knowledge is directed. Yet, they are unattainable because understanding reaches beyond experience. Kant illustrates that there cannot be a real object corresponding to the ideas of reason by referencing the contradictory nature of judgments about visible objects. Where conflicting propositions collide, Kant calls them antinomies.

The peculiarity of an antinomy lies in the fact that each of its contradictory components has equally valid justification. For instance, one can equally convincingly prove the validity of two statements: 1) the world is limited in space and has a beginning in time; 2) the world is unlimited in space and has no beginning.

Such antinomies indicate that the objects attributed with contradictory properties cannot be thought according to the laws of experience. They are the "thing-in-itself," the noumenon, which can only be thought but cannot be presented in sensory experience. Thus, the noumenal world remains inaccessible to science.

In discussing the antinomies concerning the world as a whole, Kant raises a critical philosophical issue: the concept of freedom. He examines it in relation to the notion of causality, articulating: 1) causality according to the laws of nature is not the only causality from which all phenomena in the world can be derived, as the explanation of phenomena must also posit causality through freedom; 2) there is no freedom; everything in the world occurs solely according to the strict laws of nature. It should be noted that this discussion pertains to freedom in relation to the world as a whole, that is, in a cosmological sense. Here, it is a pure transcendental idea. From experience, Kant explains, such an idea of freedom does not arise because experience and nature indicate that causality prevails in them. Reason, in turn, creates for itself the "idea of spontaneity" (free causality), which is capable of initiating a causal chain without a prior cause. This conceivable freedom is not empirical but intelligible, accessible solely through reason. In reality, if freedom—as the absolutely first cause—were to be fixed in experience, it would belong to the world of phenomena, subject to the concept of nature, where the same strict causality governs, which is examined by natural science. Therefore, in order to preserve freedom, one must posit its intelligibility and somehow "reconcile" freedom with nature. This desired "reconciliation" is only possible in one way: one must acknowledge that all phenomena possess the capacity to have dual characteristics: empirical and intelligible. The latter remain inaccessible to scientific-theoretical knowledge.

Let us reiterate that Kant discusses freedom concerning the world as a whole, that is, as a global idea, rather than merely in relation to humanity. The transcendental nature of the idea of freedom implies its applicability to all phenomena, including humanity. A person is merely one phenomenon of the sensory world, yet as such, possesses understanding and reason. It is reasonable to assume, based on the general scheme, that it is reason that serves as the cause of all voluntary actions. However, due to the intelligible nature of this cause, it is exhaustively incomprehensible to us, remaining forever concealed as the "thing-in-itself."

In the final chapter of the "Critique of Pure Reason," titled "Transcendental Doctrine of Method," the task is to define the formal conditions for the entire system of pure reason. Here, one can find numerous intriguing thoughts, particularly concerning the discipline of reason, its systematicity, and principles of application. When discussing the discipline of reason, Kant once more warns against futile attempts to penetrate beyond experience into the "alluring zones of the intellectual," into the spheres of the supersensory. By limiting the cognitive capabilities of reason while simultaneously emphasizing its unrestrained urge to go beyond the empirical, the thinker proposes three ultimate goals for reason: the freedom of will, the immortality of the soul, and the existence of God. The pure theoretical achievements of reason here are meager, as demonstrated by the antinomies; however, these three thematic spheres (freedom, soul, God) hold practical significance. Here, for instance, moral laws come into play, which touch upon the practical application of pure reason.