Epistemology: The Essence of Cognitive Activity

The Unity of Sensory and Rational Knowledge

The reflection of the world within the human consciousness, grounded in practice, occurs in two forms: sensory and rational. The process of cognition always begins with immediate, living observation, that is, with the direct interaction of the individual in practical activities with objects and phenomena. The primary forms of sensory knowledge are, as previously mentioned, sensation, perception, and imagination.

However, the process of cognition cannot be confined solely to the sensory level, which is incapable of revealing the internal, essential connections between objects and phenomena. This can only be achieved at a qualitatively new and higher stage of knowledge—at the level of abstract thinking. This is realized in three fundamental forms: concepts, judgments, and inferences (for more details, see the section on "Logic: Laws and Forms of Correct Thinking").

Sensory and logical knowledge form an inseparable unity, although there have historically been two schools of thought that have absolutized either sensory knowledge—empiricism—or logical reasoning—rationalism. From the history of philosophy, we know that it was during the era of the New Age that epistemological issues became paramount. The two extreme approaches to interpreting the relationship between sensory and rational knowledge were most clearly articulated by Bacon and Descartes.

The representatives of empiricism, the most notable among whom, besides Francis Bacon, were John Locke and Thomas Hobbes, believed that all human knowledge arises from experience. There exists, firstly, external experience, conditioned by sensations, and secondly, internal experience, where, as a result of human operations of thought—such as combination, comparison, and abstraction—more complex ideal constructs are formed from simple ideas. Innate ideas do not exist; the human soul is a blank slate. Knowledge is formed on the basis of sensory perception through principles, that is, general rules. Only judgments that express the direct fixation of facts through the senses are self-sufficient and infallible. In contrast, all other judgments require support from the results of sensory experience.

The representatives of rationalism, in addition to Descartes, included Baruch Spinoza, Gottfried Wilhelm Leibniz, Georg Wilhelm Friedrich Hegel, and others. Descartes maintained that through intuition one can discover ideas that are so clear, distinct, and self-evident—such as "I exist" and "the whole is greater than the part"—that one cannot doubt their validity. Based on these foundational innate ideas, one can build an entire system of knowledge through deduction, akin to how in Euclidean geometry all our knowledge of geometric figures is derived from a few axioms.

Thus, empiricism and rationalism represent extreme viewpoints and cannot explain the entirety of the complexity of the cognitive process. Even Immanuel Kant recognized the limitations of these approaches. In his Critique of Pure Reason, he writes: "Without sensibility, no object would be given to us; without understanding, no object would be thought. Thoughts without content are empty; intuitions without concepts are blind... The understanding cannot contemplate anything, and sensations cannot think anything. Only through their combination can knowledge arise."

Therefore, the act of cognition is always a unity, an interaction of its sensory and rational forms. Rational forms of knowledge are impossible without the sensory, from which they derive their raw material; logical thinking always utilizes sensory illustrative schemes, models, and symbols. Conversely, at the level of consciousness, sensory perception is influenced by the rational; it is not mindless but always interpreted—individuals perceive the world with thoughtful eyes. Understanding the dialectical unity of the sensory and the rational transcends the metaphysical limitations of both empiricism and rationalism.