p The picture given by sense organs is uncommonly rich and colourful. It is, however, limited and far from complete. Sensory knowledge gives us an idea only of external aspects of things. With the aid of sense organs, for example, it is possible to perceive an electric bulb but it is impossible to imagine that electricity is a stream of electrons moving at a certain velocity. Nor is it possible to perceive, through sense organs, the tremendous velocity of light, the movement of 158 elementary particles in the atom and many other complex phenomena of nature and social life.

p In a word, sensory knowledge cannot reveal the inner nature of things, their essence, the laws of their development. Yet this is the main purpose of knowledge. Only knowledge of laws, of the essence of things can serve man as a guide in his practical activity. It is here that abstract or, as it is also called, logical thought comes to his aid.

p Logical thought is a qualitatively new, higher stage in the development of knowledge. Its role is to reveal an object’s chief properties and features. It is at the stage of logical thought that man gains knowledge of the laws governing the development; of reality, so needed for his practical activity.

p Concept is the main form of logical thought. A concept reflects in objects not all their aspects, but only what is essential and general; it abstracts, casts aside secondary features. Let us consider, for example, the concept “man”. Not all the features of an individual are reflected in this concept It contains no information about his nationality, age, place of residence, the time when he lives, and so on. Fixed in this concept is only what is general and essential, inherent in every man—the ability to work, to produce material wealth, to think and to speak. Similarly, the concepts “tree”, “animal”, “society”, “production”, “class”, “party”, etc., cover what is general and essential in objects.

p Concepts arise on the basis of practice. Before forming, for example, the concepts of triangle, square and other geometric figures, man in his practical activities came into contact with numerous objectively existing triangular, square and other objects. Practice is the basis of the generalising activity of the mind, the processing of the data furnished by sensory knowledge. As man acted upon the objects of the material world, he compared them and, abstracting from everything accidental and secondary, singled out what was general and essential in them, and ascertained their objective importance in the process of production and their place in man’s labour and life. It is the continuous process of creative work and man’s ceaseless efforts to make nature serve him and the interests of production that gave rise to scientific concepts such as “electric power”, “atomic energy”, “hybridisation”, “melioration” 159 and many, many others.

p At first glance it might seem that concepts or abstractions are poorer than direct sense perceptions. But, Lenin noted, even the simplest concept reflects nature more deeply, fully and truly because it reflects ’the internal aspects of reality inaccessible to direct sensory cognition. It reflects nature more fully, because it covers not one bbject or small group of objects, but their mass, their boundless multitude.

p The transition from the sensory to the abstract represents a dialectical leap in the process of knowledge, in its movement from the lower to the higher. This leap is made through practice. Only the practical activity of people, aimed at transforming objects and phenomena of the world, makes it possible to penetrate their essence, to differentiate between the important and the secondary, the internal and the external. The higher the degree of development of practical activity, and the more powerful its transforming force, the deeper and more diverse is the knowledge of man.

p Concepts reflect the changing world, the constantly developing practice, and hence they themselves must be flexible and mobile. Mobility and flexibility of concepts is expressed in the amplification and deepening of existing concepts and also in the formation of new ones corresponding to the changed objective conditions, the changed practice.

p Other forms of thought—judgements and conclusionsare formed on the basis of concepts.

p Judgement is a form of thought in which something is asserted (for example, “socialism is peace”) or something is denied (for example, “Marxism is not a dogma”). As we see, a judgement consists of definite concepts. In the judgements given above these are the concepts “socialism”, “peace”, “Marxism”, and “dogma”. At the same time it is impossible to understand these concepts without other judgements, such as “socialism is a social system based on public ownership”, etc. Concepts and judgements are thus interconnected. Judgements are also interconnected. Their connection makes up a special form of logical thought—conclusion. A conclusion is a new judgement obtained on the basis of other judgements (premises). Through conclusions drawn from available knowledge we can gain new knowledge, and 160 this is what makes for their great importance in cognition.

p Such higher forms of knowledge as hypothesis and theory represent an intricate combination of concepts, judgements and conclusions. A hypothesis is an assumption about phenomena, events, laws. The assumptions about the origin of life on Earth or the origin of the solar system are examples of hypotheses. Scientific theories embody deep, all-round knowledge of definite processes or fields of activity. This type of knowledge has been tested by experiment and practice. For example, the modern theory of the atomic nucleus, the theory of relativity in physics, and the materialist theory of heredity in biology are all scientific theories. Historical materialism is the truly scientific theory of the development of society.

p Thus, we see that knowledge in its dialectical development traverses a long road, from the simplest sensations to complex scientific theories.

p This picture of the formation of scientific theories constitutes only a general trend in the dialectical-materialist process of knowledge. In reality it often happens that under the influence of practical needs the researcher first conceives an idea which foreshadows the movement of thought and indicates the main directions of scientific study. At times this idea provides only a very vague, approximate response to demands posed by practice. In the course of the realisation of the idea and in the process of investigation concepts, images and judgements arise that concretise the idea, embody it in the flesh of scientific premises, conclusions, and laws which after passing the test of practice turn in their totality and unity into scientific theory.

It should be noted that the idea which foreshadows theory is born not only under the impact of practice; it is also dictated by the logical development of science itself. And in both cases the idea is not simply the fruit of its author’s imagination. Accumulating, as it does, the already available knowledge, it is in its way a result of the development of science and practice. An immense role in the formation of ideas and their realisation and development into a scientific theory is played by the scientist, by his experience, knowledge, intuition, imagination and creative abilities.