45)On the criteria of true knowledge.

One of the fundamental principles of scientific thought is that a statement is true if it can be proved that it is applicable to a given situation. This principle is expressed by the term "realizability". Through the realization of an idea in practical action, knowledge is measured against its object revealing the true measure of its objec­tivity or the truth of its content. That part of knowledge that is di­rectly or indirectly confirmed by practice, i.e. effectively realized in practice, is true.

As a criterion of truth, practice "works" not only in its sensuous "nakedness", as an object-related physical activity, in particular in experiment. It also appears in mediated form —as logic tempered in the crucible of experience. Logic may be said to be mediated prac­tice. Practice is many-sided, ranging from empirical everyday experiences to the most rigorous scientific experiments. The practice of primitive man obtaining fire by means of friction is one thing, and quite another, the practice of mediaeval alchemists seeking for ways of transforming various me­tals into gold. Contemporary physical experiments involving equip­ment of tremendous resolving power, and computer calculations — these are also practice. In the course of the development of true knowledge, and of increasing its volume, science and practice form an ever closer unity.

2.Practice as the Basis and Purpose of Cognition

Practice is the material, sensuously objective and goal-directed ac­tivity of men intended to master and transform natural and social ob­jects, and constituting the universal basis, the motive force of the de­velopment of human society and knowledge, \ Practice designates not only, and not so much, the sensuously objective activity of a separate individual as the total activity and experience of the entire mankind in its historical development. Practical activity is social both in its content and in the mode of its realization. Contemporary practice is a result of world history, a result that embodies infinitely varied re­lations between men and nature and among men in the process of material and non-material production. Being the principal mode of man's social existence and the decisive form of his self-assertion in the world, practice acts as a complex integral system incorporating such elements as need, goal, motive, separate actions, movements, acts, the object at which activity is directed, the instruments of achieving the goal, and finally the result of activity. In practice, somebody always does something to create something out of some­thing with the help of something for some purpose.

Social practice forms a dialectical unity with cognitive activity, with theory. It performs three functions in relation to the latter. First, it is the source and the basis of cognition, its motive force; it provides the necessary factual material for it, subject to generaliza­tion and theoretical processing. It thus feeds cognition as soil feeds trees, and does not let it become divorced from real life. Second, practice is a mode of application of knowledge, and in this sense it is the goal of cognition. Scientific knowledge has a practical meaning only if it is implemented in life: practice is the arena in which the power of knowledge is applied. The ultimate goal of cog­nition is not knowledge in itself but practical transformation of re­ality to satisfy society's material and non-material needs through harmonizing its relationship with nature. Third, practice is the crite­rion and measure of the truth of the results of cognition. Only that knowledge which has passed through the purifying fire of practice can lay claims to objective ness, reliability, and truth.

We can thus say that practice is the basis for the formation and development of cognition at all its stages, the source of knowledge and criterion of the truth of the results of the cognitive process.

The main kinds of practice are the material-production activity and social-transforming activity of the masses (the latter includes people's activity in the social, political and cultural spheres of so­ciety's life). Natural-scientific and social experiments are special kinds of scientific practice.

The feedback mechanism permits the implementation of correc­tive influences of theoretical and practical activity on each other, which ensures the role of practice as the criterion of truth.

Inasmuch as practical activity is conscious, the mental, spiritual element is undoubtedly part and parcel of it. The position of isolating the material and practical activity from the intellectual and theoretical one is hostile to dialectical materialism. These kinds of activity form an indissoluble unity. To resort to the dry language of categories, a part is not the whole, and substituting the one for the other is fraught with theoretical-methodological and worldview errors.