Knowledge, Theory of

also epistemology, a branch of philosophy that is concerned with the nature and the potential extent of knowledge, the relation between knowledge and reality, the general premises of knowledge, and the necessary conditions for establishing the validity and truth of knowledge. In contrast to such scientific disciplines as psychology or the physiology of the higher nervous system, the theory of knowledge as a philosophical discipline does not analyze those specific functions of the mind that enable a given subject to reach a particular cognitive result; rather, it analyzes the universal bases for regarding that result as knowledge—knowledge representing the true reality of things. The two main trends in the theory of knowledge are materialism and idealism.

Historical development. In antiquity, the central problem for the theory of knowledge was the relation between knowledge and opinion, as well as between truth and error. Knowledge was understood as being in unity with its object: in Plato’s idealist view, the object of knowledge was the world of ideas, while for the Greek materialists it was nature. The premise of classical philosophy was that knowledge is a distinctive copy of an object; this premise was accepted as something quite natural and was not even a subject of particular debate. What held the greatest interest was the attempt to explain the process by which an object is converted into knowledge. The thesis that knowledge is one with its object corresponded specifically to an interpretation of the process of cognition that did not include the concept of an active subject. A true object could only be “given” to the perceiving subject, while any product of the latter’s creative activity or subjective cognition could merely constitute false opinion.

A major development in the theory of knowledge took place in the 17th and 18th centuries, at a time when the central concern of European philosophy was the connection between the self and the external world, or between inner and outer experience. The theory of knowledge was seen not only as the analysis of philosophical and metaphysical knowledge but also as a critical investigation of scientific knowledge. At this time the problems treated by the theory of knowledge were central to philosophy, since they were the starting point in the construction of philosophical systems, sometimes even coinciding with the systems themselves. What was sought was knowledge that was absolutely certain; such knowledge would be the starting point and at the same time the foundation for all other knowledge and would serve as the measure by which the truth of all other knowledge could be evaluated.

The different paths taken in the search for such knowledge led to the rise of rationalism and empiricism. The orientation toward the mechanical and mathematical sciences of the time and the attempt to apply scientific methods directly to philosophical problems resulted in the rationalist conception of innate ideas, which were seen as analogous to geometric axioms and from which all other knowledge could be somehow deduced. The empiricist point of view identified sense data—regarded as the elementary units of knowledge—as specific “atoms” whose interaction produces all other knowable forms.

The relation between sense and reason, or between the empirical and the rational, was a subject of epistemological study not only for determining the origin of knowledge but above all for establishing the logical foundations of a system of knowledge. It was in this context that 17th- and 18th-century philosophy analyzed the relationship between subject and material substance, or between the self and the external world, together with the related problems of inner and outer experience and primary and secondary qualities. These problems originated in R. Descartes’ categorization of the subject, or the subjective, as something sharply distinct from the material substance and logically opposite to it. The Cartesian doctrine of innate ideas was sharply criticized by the proponents of materialist empiricism, who opposed the tendency of idealist rationalism to convert thought into an independent substance, or a “rational thing.” While the empiricists recognized the existence of the self as a psychic phenomenon directly experienced by the perceiving subject, they failed to explain successfully the origin and function of inner experience—a problem that was insoluble within the framework of metaphysical materialism of the time. The weaknesses of metaphysical materialism were exploited in the subjective idealism of G. Berkeley and D. Hume, whose speculations dealt primarily with epistemological problems.

In classical German philosophy, the theory of knowledge was studied in conjunction with the historical development of forms of practical and cognitive activity. I. Kant was the first to undertake the construction of a theory of knowledge that would be completely independent of any ontological or psychological assumptions about reality. Kant postulated a reality dependent on cognition itself, wherein the object as well as the subject of knowledge exist only as forms of ongoing cognitive activity. According to Kant, the objectification of the content of knowledge is a form of the subject’s activity, and the subject does not exist outside the object of his cognition; on the other hand, objects exist as such, in Kant’s view, only within forms of the subject’s activity. The thing-in-itself—that is, the reality that exists apart from any relation to the cognizing subject—is given to the latter only in the forms of objects that are essentially products of his own creative activity. Kant’s aim of creating a “pure” theory of knowledge, independent of ontological premises, was only partially realized. The attainment of a “pure epistemologism” was left to neo-Kantianism, which rejected not only the thing-in-itself but even the cognizing subject.

After Kant, classical German philosophy sought to overcome the split between epistemological and ontological questions. Among pre-Marxist philosophers, G. Hegel was the most successful in resolving this problem. Hegel maintained that subject and object are dialectically interdependent and demonstrated the fallacy of their being considered in metaphysical opposition to each other. According to Hegel, subject and object are essentially one and the same, inasmuch as the foundation of reality is the self-development of the absolute spirit—this spirit being the absolute subject that has itself as its object. From this follows Hegel’s principle, based on objective idealism, that dialectics, logic, and the theory of knowledge coincide.

The study of the theory of knowledge assumed certain distinctive features in 20th-century bourgeois philosophy. For the first time, idealist empiricism in some of its forms (for example, in Machism and neorealism) is coupled with ontologism—that is, with certain admissions about reality and its properties. The concept of elementary sense data, which is fundamental to empiricism, is interpreted as applying not to the individual’s subjective mental experience but to certain sensory essences that exist objectively (that is, independently of individual consciousness). Examples of such essences are the “neutral” world elements of E. Mach, the neorealists’ sensory data, and B. Russell’s “sensi-bilia.” These and similar theories of knowledge combine features of both subjective and objective idealism.

Another feature that distinguishes modern Western philosophy is the emergence of such trends as logical positivism, neopos-itivism, and analytical philosophy, which reject the theory of knowledge and all classical philosophy as meaningless. From the point of view of logical positivism, scientific knowledge constitutes the ideal of meaningfulness. All scientific propositions can be classified as either synthetic (the statements of empirical science) or analytic (the truths of logic and mathematics). The questions of classical philosophy, on the other hand, have no meaning, since none of the possible answers to such questions can be classified as either empirical-synthetic or analytic statements. According to logical positivism, such epistemological problems as the relation of the subject to the object or the nature of reality are typical pseudoproblems. In contrast to neopositivism, existentialism criticizes the theory of knowledge (as well as all classical philosophical “metaphysics”) because of its close relation to rules adopted to formulate questions in science or in ordinary language.

The theory of knowledge in Marxist-Leninist philosophy. Rejecting all forms of epistemological idealism, the Marxist-Leninist theory of knowledge takes as its starting point a consistently materialist solution to the fundamental question of philosophy; that is, it regards the knowable material world, or objective reality, as existing outside of and independently of consciousness. From the fundamental thesis that knowledge is materially conditioned it follows that the cognitive process is effected not by some “pure” consciousness or self-consciousness that is divorced from man but rather by an actual human being through his consciousness. Dialectical materialism is grounded in the proposition that the world is knowable and emphatically rejects agnosticism and its assertion that the world cannot be known.

While consistently materialist, the Marxist-Leninist theory of knowledge is not a mere extension of pre-Marxist philosophy’s materialist approach to epistemological problems. In the Marxist-Leninist philosophical system, the theory of knowledge is fundamentally transformed in both structure and content, as well as in the nature of its connection with other branches of philosophical and social theory and with problems of actual life.

The chief distinctive feature of the dialectical-materialist theory of knowledge consists in its being developed on the basis of the materialistically interpreted thesis of the unity of dialectics, logic, and the theory of knowledge. In Lenin’s words, “Dialectics is the theory of knowledge of (Hegel and) Marxism” (Poln. sobr. soch., 5th ed., vol. 29, p. 321). This means that neither “pure ontology” nor “pure epistemology” exists in the Marxist-Leninist philosophical system. In dealing with any major philosophical problem, dialectical materialism views the ontological and epistemological aspects in their unity. Examples of this radically new approach can be found in Lenin’s Materialism and Empir-iocriticism. This work contains an epistemological interpretation of a number of categories that in metaphysical philosophy would be regarded as purely ontological—for example, matter, motion, time, space, and causality. At the same time, the Marxist-Leninist solution for any particular epistemological problem proceeds from certain conceptions with respect to the structure of objective reality and the place occupied within it by the cognitive process.

Dialectical materialism not only removes the opposition between the theory of knowledge and ontology but also brings to an end the divorce between epistemological and social problems that is typical of non-Marxist philosophy. Cognition is essentially social in character and consequently cannot be understood in isolation from the objective and practical activity that is the true essence of man. Therefore the subject of cognition is derived from the subject of practice. The cognizing subject is not an individual isolated from other people (the “epistemological Robinson Crusoe” of metaphysical philosophy), but a human being whose life is engaged with that of society and who utilizes socially developed forms of cognitive activity—whether material forms, such as implements of labor, instruments, and tools, or ideal, such as language and logical categories.

Human beings receive their initial knowledge of the world through the senses—through perceptions, sensations, and images. The Marxist theory of knowledge, in opposition to the idealist and metaphysical interpretations of sensationalism, maintains that rational knowledge (thought, concepts) cannot be reduced to the mere summation or mechanical transformation of data perceived by the senses. The results of thinking are represented in new knowledge that is not directly contained in sense data; moreover, these results also affect the structure and content of sensory knowledge. The empirical data with which science deals presuppose a series of theoretical idealizations; these data are obtained through the use of theoretical propositions in describing the content of sensory experience. Furthermore, sensory experience, which lies at the foundation of the cognitive process, is not a passive reception of the impressions made by objects of the external world but rather a function of practical and objective sensory activity.

In re-creating the object of knowledge, theoretical thinking follows the method of ascending from the abstract to the concrete. Principles that are inseparably linked to this method are the unity of the logical and the historical and the unity of analysis and synthesis. The categories and laws of materialist dialectics, which represent the forms in which objective reality is reflected in consciousness, also constitute the methodological principles of scientific theoretical activity. The general pattern of the cognitive process is expressed in Lenin’s formulation: “From living perception to abstract thought, and from this to practice” (ibid., pp. 152–53).

The nature and level of development of material practice—that is, of activity aimed at transforming nature and society—also determine the limits of knowledge in any specific historical context. In a society of antagonistic classes, the nature of the practical activity of one or another class essentially determines to what extent the members of that class can attain objectively true knowledge. The revolutionary transformation of society by the working class both ensures the worldwide historical progress of humanity and contributes directly to the advance of knowledge.

In the Marxist-Leninist theory of knowledge, the cognitive process is not simply regarded in the form that the process takes in the mind of an individual; rather, it is interpreted as the sociohistorical process of the development of knowledge. As Lenin maintained, the theory of knowledge “must regard its subject matter historically, studying and generalising the origin and development of knowledge, the transition from non-knowledge to knowledge” (ibid., vol. 26, p. 55). An individual’s knowledge of the world is mediated by the development of knowledge in its worldwide historical context. It is characteristic of pre-Marxist and non-Marxist theories of knowledge to reduce the problem of establishing a basis for knowledge to the search for some absolutely unchangeable, nonhistorical, ultimate basis for all knowledge that would permit a suprahistorical evaluation of the products of cognitive activity. The Marxist-Leninist theory of knowledge, consistent with the dialectical-materialist principle of his-toricism, emphasizes the specifically historical character of the foundations of knowledge. As human knowledge develops, changes take place in the logical structure of systems of knowledge—particularly of scientific theories—and this process is specifically related to changes taking place in social and cultural institutions.

Emphatically opposing all forms of epistemological relativism, dialectical materialism develops the thesis of the dialectical relation between absolute and relative truth and stresses the objective truth in human knowledge—namely, a content that is independent both of the individual and of humanity as a whole. Stages of knowledge are steps along the way to an ever more accurate and thorough cognitive re-creation of the objective world. Sociohistorical practice constitutes not only the basis and goal of knowledge but also the criterion of truth.

The keystone of the materialist theory of knowledge is the principle of reflection. The dialectical-materialist theory of reflection, whose foundations were laid by Marx and Engels and which was further elaborated and refined by Lenin, lies at the heart of the entire Marxist-Leninist philosophy. In the dialectical-materialist system, the theory of knowledge and the theory of reflection do not altogether coincide. The theory of reflection, in addition to analyzing cognition and knowledge, investigates forms of reflection that exist at the precognitive level, especially in inanimate nature.

The Marxist-Leninist theory of reflection is substantively different from the contemplative theory of reflection of pre-Marxist metaphysical materialism. Dialectical materialism demonstrates that human reflection, as such, is based on and inseparably bound to the transforming function of practical activity. Therefore the cognitive process itself is not a passive contemplation of certain externally given objects; rather, it takes the form of a series of ideal operations organized into a system used to mold specific “ideal objects.” These objects serve as the means of cognitive mastery of the objective world and as the means by which the latter is reflected. Reflection, therefore, is seen as inseparable from the process of material and ideal creativity.

The history of the theory of knowledge has shown that this branch of philosophy, to a greater extent than any other, is linked to science and at times serves to analyze and interpret scientific data critically—although not always adequately, of course. Thus, to a significant extent the Kantian theory of knowledge is an attempt to interpret philosophically Newtonian mechanics; thus, too, logical positivism claims to provide a conceptual formulation of the cognitive procedures characterizing modern science. One should not, however, equate the theory of knowledge with any kind of metascience. The theory of knowledge developed as a field of philosophical knowledge long before the birth of modern science; moreover, not all metascientific study is epistemological in nature. The analysis of the logical structure of a given scientific theory (for example, metamathematics or metalogic) is not, in and of itself, an epistemological investigation; neither is the study of the connections between the linguistic elements of entire classes of scientific theories, or what has been called the logical analysis of the language of science, which makes use of the instruments of modern formal logic.

The epistemological interpretation of science begins with the examination of theoretical constructs in order to determine whether they truly correspond to reality, whether the status of existence can be ascribed to certain abstract objects used in theory, and whether certain statements in a specific scientific field can be assessed in terms of their analytic or synthetic value. Such research is related to the analysis of the content of empirical data—which support a theory—with respect to their validity and to the relationship between reliable and problematic knowledge that they contain. The epistemological interpretation of specific scientific theories represents the application of certain general principles of the theory of knowledge to the analysis of particular cases; at the same time, it represents the assimilation of new scientific results in order to refine certain general epistemological postulates or sometimes to revise them. For example, the revolution in physics at the turn of the 20th century demonstrated that the theory of knowledge of contemplative metaphysical materialism was completely untenable, while the theory of knowledge advanced by Machism and logical positivism came into obvious conflict with modern science. Lenin analyzed the development of natural science in the early 20th century and contributed a creative formulation of the basic principles of the dialectical-materialist theory of knowledge.

The epistemological assimilation of new scientific data has nothing in common with simple “inductive generalization”: scientific findings may require new epistemological interpretations, and these in turn necessarily lead back to the classical epistemological set of problems.

The second half of the 20th century has made clearer than ever the lack of any substance in the idealists’ assertions—as most fully expressed by the neo-Kantians—that the theory of knowledge is a distinct and special scientific discipline having nothing in common with “metaphysics.” The theory of knowledge has been and remains a particular field of philosophical knowledge and as such cannot be separated from the resolution of the fundamental problem of perception of the world.