German Classical Philosophy

The “Copernican Revolution” of I. Kant in Philosophy

German classical philosophy holds a distinctive place in the history of thought. The ideas of its most prominent representatives, Kant and Hegel, are indispensable for envisioning subsequent philosophical developments. Alongside them emerged two significant concepts—the active nature of humanity and the idea of progress. German classical philosophy is a product of the Enlightenment and, in many ways, belongs to it. However, while the French Enlightenment found concrete expression in the French Revolution, the German Enlightenment, hampered by the weakness of the German bourgeoisie, manifested as a revolution of consciousness, aspiring to establish moral principles of human freedom through educated universal reason.

When discussing German classical philosophy, we refer, following the historical-philosophical tradition established during the Soviet era, to the teachings of five German philosophers: Immanuel Kant (1724-1804), Johann Gottlieb Fichte (1762-1814), Friedrich Wilhelm Joseph Schelling (1775-1854), Georg Wilhelm Friedrich Hegel (1770-1831), and Ludwig Andreas Feuerbach (1804-1872). In this section, we will focus on the doctrines of three philosophers—Kant, Hegel, and Feuerbach—while noting the "intermediate" character of Fichte's and Schelling's philosophies between Kant and Hegel.

The "Copernican Revolution" of I. Kant in Philosophy

The founder of German classical idealism is Immanuel Kant (1724-1804). Born in East Prussia, in the city of Königsberg (now Kaliningrad), he spent his entire life there without leaving. Externally, his life was unremarkable, marked perhaps only by an excessive pedantry; one might say that he dedicated his whole life to science. After completing his studies at the university in 1745, Kant worked for nine years as a private tutor, earning a living while engaging in philosophical inquiries during his free time. In 1755, he defended his dissertation and earned the title of Privatdozent. However, he had to wait fifteen years for a professorship at the University of Königsberg, during which time he worked as an assistant librarian at the palace library. Upon receiving the position of professor of logic and metaphysics in 1770, he taught a series of courses in philosophy, mathematics, and physics until 1797. It was here that he penned his major philosophical works.

Kant's oeuvre is often divided into two periods: the pre-critical and the critical. While there is no profound chasm between these periods, their differences are noteworthy, particularly in terms of the focus of his philosophical inquiries. In the pre-critical period, Kant devoted significant attention to cosmogony. His hypothesis regarding the origin of the Solar System remains scientifically relevant to this day. However, Kant's most significant contributions to philosophy are associated with his critical period, during which he concentrated on epistemological issues, specifically the possibilities and limits of human knowledge. It is in this realm that Kant was destined, as he expressed, to effect a "Copernican revolution."

The beginning of Kant's critical period is commonly traced to 1770, marked by a transformation in his views influenced by his acquaintance with the works of the English philosopher David Hume in the 1760s. "Hume awakened me from dogmatic slumber," Kant remarked.

David Hume (1711-1776), an English philosopher and the founder of agnosticism, like many philosophers of the Early Modern period, was primarily concerned with questions of knowledge—what and how humans can know the world. As a sensualist, Hume concluded that the comprehension of truth is impossible. Moreover, he argued that even our judgments regarding the existence of objects in the surrounding world cannot be deemed reliable. Hume reasoned simply: the world is given to us through our senses; thus, our statements and judgments pertain to our sensations rather than to the objects themselves. Concerning the objects themselves, we can say nothing; we cannot even know what causes our sensations. According to Hume, materialists claim that these sensations are triggered by objects that exist objectively in the world, while idealists view them as products of our psyche. However, we cannot know this, Hume argued, because we cannot transcend our sensations. In practice, we act based on habit rather than on true knowledge. This perspective came to be known in philosophy as "agnosticism" (from the Greek "a-" meaning "not" and "gnosis" meaning "knowledge"), and Hume is its progenitor and consistent advocate. Some philosophers trace the roots of agnosticism back to ancient Greek skepticism. While there is some truth to this, ancient skepticism expresses only doubt regarding the capacity of human reason to provide an adequate representation of external objects but never doubts the existence of that very world, the cosmos, of which humanity is a part. As we shall see, ancient skepticism aligns more closely with Kantian agnosticism than with Hume's.

Kant's engagement with Hume's ideas led him to reassess the subject-object relationship in the process of cognition. Knowledge is an interplay between the subject and the object, wherein the subject—namely, the individual—encounters the object, creating an image, a concept, and thereby knowledge of the object. In this context, an essential question arises regarding what or who determines the content and form of our knowledge. The philosophical tradition stemming from antiquity maintained that the object plays the active role in the epistemic relationship; it defines both the content and the form of our knowledge, while the subject passively mirrors the object's properties, much like a mirror reflecting reality. The task of the subject, like that of a mirror, is to accurately reproduce these properties, ensuring that the content of the image or concept aligns as closely as possible with the object's essence. For the ancients, this approach was taken for granted, as human cognition was seen as an encounter with the cosmos's ideal content. Hence, Plato posited that the process of knowledge is akin to the soul's recollection of what it had seen in the realm of ideas. In the Middle Ages, the highest truth was similarly attained through revelation, with God directly or through His apostles disclosing truth to humanity. Although the Early Modern period proclaimed through Descartes that human reason is the highest criterion of truth, this reason remained dependent on God, thereby remaining passive.

Hume broke this view, demonstrating that in such a case, truth is unattainable. Hume posed this problem in philosophy, and Kant was the first to grasp it fully. However, Kant disagreed with Hume's conclusion that the attainment of truth is impossible. Kant believed that a way forward could be found by revising the subject-object relationship in cognition, positing that the subject is the active participant, and our knowledge results from the subject's activity. This constitutes, in Kant's own words, the essence of his "Copernican revolution" in philosophy. Thus, according to Kant, the task of philosophy is to clarify the human capacity for knowledge, to identify what is a priori, to unveil the mechanisms of the cognitive process. Kant addressed this task in his pivotal work, "Critique of Pure Reason," published in 1781.

Human beings possess three means of knowledge: sense perception, understanding, and reason. Following tradition, Kant distinguishes between empirical thought and rational thought based on their connection to the world of objects. Empirical thinking pertains to concrete matters, while rational thought concerns thinking about thinking itself. Each of these three forms of knowledge corresponds to different sciences: mathematics, natural science, and philosophy. Thus, the question of how a priori empirical, understanding, and rational knowledge is possible transforms into three inquiries: 1) how is mathematics possible, 2) how is natural science possible, and 3) how is philosophy possible?

Empirical knowledge, and consequently geometry and arithmetic, is possible because space and time are a priori inherent to us. According to Kant, space and time are not objective properties of external objects and phenomena but rather general forms of perception that are a priori characteristics of human cognition, through which mathematical propositions attain the status of universality and necessity, that is, truth. If space and time were derived empirically, then mathematical propositions would not be universal and necessary, and thus not true; yet, the truth of mathematical science was evident even to the ancient Greeks. In the "Critique of Pure Reason," the conditions for a priori empirical knowledge are examined in the section titled "Transcendental Aesthetics." The concept of "transcendental" in Kant's thought refers to all that pertains to a priori forms of knowledge. "I call that transcendental," Kant writes, "which concerns our knowledge of objects, as it must be possible a priori."

However, empirical knowledge provides us only with representations of objects and phenomena; it does not, by itself, yield knowledge, which arises only through the engagement of another capacity of the soul—reasoning. Empirical knowledge supplies us with material that is organized according to the a priori forms of sensibility—space and time—needing to be comprehended by reason. "The understanding cannot contemplate anything, and the senses cannot think anything. Only from their conjunction can knowledge arise."

Through understanding, the representations derived from limited empirical experience acquire the form of universality and necessity. Understanding synthesizes the diversity of sensory impressions into the unity of concepts. This capacity of understanding is conditioned by the a priori possession of categories—general concepts that serve as forms of thought. Kant identifies four groups of categories through which understanding synthesizes empirical experience: quantity (unity, plurality, totality), quality (reality, negation, limitation), relation (substance and accident, cause and effect, interaction), and modality (possibility and impossibility, existence and non-existence, necessity and contingency). Understanding does not passively interpret the data of sensory experience; rather, it constructs the image of the object through these categories. However, this means that the image of the object present in our consciousness is not identical to the object itself. The image constitutes a unity of objective content determined by the object and a subjective form—namely, the a priori forms of sensibility and the categories of understanding. The thing that exists in our mind is a phenomenon, while the thing that exists in itself is the "thing-in-itself," or noumenon; these can never coincide, as we cannot know the objective world without imposing our cognitive forms upon it, without constructing it. Kant restricts the possibility of knowledge solely to the realm of phenomena, separating the phenomenon from the essence. Essentially, he positions himself as an inconsistent agnostic, in contrast to Hume.

Yet, in addition to sensibility and understanding, humanity possesses another faculty that aspires to attain certain knowledge—reason. Dogmatic philosophy (i.e., pre-Kantian philosophy) regarded this faculty as the highest cognitive ability, producing philosophy as the supreme achievement of human intellect.

According to Kant, the task of reason differs from that of sensibility and understanding. Reason transcends the limits of empirical experience; it does not formulate transcendental principles that condition sensory and understanding knowledge but rather establishes transcendental principles that enable a higher unity of knowledge. The concepts of reason lead us beyond experience, although they do not exclude empirical knowledge, which is included as a part. The concepts of reason are akin to what Plato referred to as ideas. Their function is to determine the ends of both theoretical and practical human activity. Philosophy, as a system of unique philosophical knowledge existing alongside mathematics and natural science, is impossible. However, it is possible, first as critical philosophy, which investigates our capacities for knowledge, and second, philosophy is necessary to explore the ultimate purpose of human existence, which is morality.

In ethics, as in knowledge, Kant seeks to discover a universal moral rule that does not arise from experience. He asserts that duty—"you ought to"—is an absolute obligation that does not stem from experience. If this is the case, there must be a general absolute principle according to which one must act—a universal moral rule. In the "Critique of Practical Reason," Kant formulates this principle, calling it the categorical imperative. He articulates it thus: "Act only according to that maxim whereby you can at the same time will that it should become a universal law." Closely related to this is another interpretation of the principle, according to which a person, as a rational being, exists as an end in itself; thus, one must treat oneself and others as ends and never merely as means.

In his political theory, Kant begins with the rights of the individual, deriving them from the transcendental properties of humanity. If in morality one must treat another person as an end, then in law one must also respect the rights of others. Kant was among the first to speak of human rights and the rule of law.

The contributions of I. Kant to philosophy are substantial. His influence on the subsequent development of philosophical thought is undeniable. Kant deepened and broadened our understanding of the possibilities and limits of human knowledge, refuting Hume's agnosticism while simultaneously tempering the unchecked optimism of rationalism. He made a fruitful attempt to synthesize empiricism and rationalism, which significantly shaped the evolution and understanding of science and its role in society in the 19th and 20th centuries.