While assessing the significance of various schools of the modern philosophy of science and comparing their programmes and views on fundamental methodological problems, we have never missed an opportunity to outline, if only schematically, the attitude of dialectical materialism (or materialistic dialectics) to each issue under consideration. Now, in order to characterise materialistic dialectics as an alternative to positivism, we ought to take a somewhat closer look at its basic concepts and present them in a broader perspective.

Of course, it would be presumptuous even to attempt to give an exhaustive account of Marxist philosophy within the scope of this publication. We shall therefore confine ourselves to the relationship of philosophy and special sciences, the objectivity of scientific knowledge and causality, i.e. to the main problems which we have already discussed in connection with the crisis of positivism and with the programmes of alternative doctrines within the framework of the modern philosophy of science and which constitute, as we have shown, the core of any methodological programme.

From its very first steps Marxist philosophy, continuing the materialistic and dialectical traditions of all previous philosophy has been the antipode of positivism. There is no need to reproduce here the history of their struggle, the more so as its outcome is well known. The prestige of materialistic dialectics as the methodology of cognition and as the world view is steadily growing, winning over to its side the most prominent representatives of modern science. Marxist philosophy, assimilating every new achievement of social and scientific progress and constantly enriching itself, is extending its influence to ever new regions of the world, the only means of its “expansion” being, as before, the logic of truth. It is precisely this logic, confirmed by life itself, that underlies its high scientific repute. By contrast, positivist philosophy, represented now by a dozen or so of its champions, the living relics of the past, is undergoing a profound ideological crisis evidently marking the closing stage of its history.

The dramatic story of the struggle between Marxist philosophy and various trends of positivism suggests certain conclusions which appear to be particularly instructive in the light of the present-day debate on the methodology of scientific cognition, as they are directly related to the main controversial issues. In this connection special importance attaches to the difference between the Marxist and positivist views on the relation of philosophy to special sciences, as well as on the relation of science in general to the unscientific forms of consciousness.

As we have earlier indicated, one of the key points in the programmes of all positivist schools without exception has always been the opposition to metaphysics, i.e. to everything that passes beyond the limits of scientific knowledge. Indeed, the only difference between the successive stages or phases of the evolution of positivism consisted, perhaps, in the difference of the concepts of scientificity and, consequently, in different lines of demarcation between science and “non-science”.

This circumstance, however, has nothing to do with the ill luck of positivist philosophy, since the delimitation of these two spheres of human and social consciousness is indeed absolutely necessary. No one in our time, except, perhaps, theologists (who are not averse to partaking in the fruit of science either), would raise any objections to the separation of science and religion if only for the simple reason that they represent entirely different forms of social consciousness with their own traditions, specific features and functions in society, not to speak of the religious prejudices that have always been a formidable obstacle in the way of scientific progress.

Besides religion, there exist other forms of nonscientific consciousness, such as, for instance, aesthetic consciousness and “common sense”. They should also be distinguished from science as such, though there is no sharp line of demarcation between them. Indeed, scientific knowledge grows on the rich soil of man’s everyday experience, and the artistic perception of the world inspires creative scientific endeavour. It would be impossible to understand science, its origin, motive forces and the nature of scientific thinking itself if we left out of account the blood vessels connecting science with living humanity, its everyday needs and aspirations, as well as the enormous wealth of labour experience accumulated by mankind. Said Goethe: “All theory, dear friend, is grey, but the golden tree of actual life springs ever green.”

The fact that the links between science and the arts have not yet been properly explored gives no grounds for ignoring their obvious mutually beneficial influence. On the contrary, the more complex and uncommon their relations, the greater should be the philosophers’ desire to get at the root of their extraordinary alliance, since they may find there a clue to the mystery of human thinking. The discoveries that may await them on this path are being eagerly looked forward to by science, as they will essentially affect the further course of scientific and technological progress, rationalise the development of technology and raise the intellectual standards of human life.

There is no need to discuss these problems in detail, since our purpose at present is to underscore the importance of demarcating science and non-scientific knowledge. However, such a demarcation cannot be an aim in itself. The close links existing between science and everyday life, science and the arts, common sense and true knowledge, as well as between science and other fields of social life indicate that it should be but a preliminary stage for further investigations. When social life and social consciousness are divided respectively into more or less independent spheres and forms, the next step will be to focus our attention on their interconnection. This stage, however, will hardly be the final one either, since the investigation of their links will lead to a more profound and concrete understanding of differences between them. This process, alas, has no end, just like the process of cognition in general.

We may sound not very optimistic, but one of the tasks of science, as distinct from religion and other forms of myths consists in giving man correct ideas of himself and of the surrounding world, the ideas that would be concrete, connected with reality and therefore testable, rather than in his illusory consolation. As to the arts and common sense, science differs from them by the precision of its statements, accuracy of calculations and forecasts, as well as by the reliability of its conclusions.

As is seen from these considerations, very general and sketchy as they are, the nature of scientific knowledge can only be understood after it is singled out of other forms of human consciousness and presented as- a historical process, i.e. with its essential links, both logical and historical. It should be noted that the rapid scientific development over the past decades and the crucial changes of many fundamental concepts of the world have exposed the links between science and other social activities and made their interdependence common knowledge. The immaturity of these links in the period of the inception of positivism, however, cannot justify this philosophy for their methodological distortion, particularly at the later stages of its evolution when these links became more apparent.

As early as the beginning of the 19th century Hegel defined the basic principles underlying the approach to this question. These principles, though in idealistic attire, carried profound dialectical meaning which ensured their viability till our time. All that was needed (in Hegel’s time at any rate) in order to solve in principle the problem of the relationship of science to the non-scientific forms of human consciousness was dialectics. It was to show the complexity and the contradictory nature of this relationship: on the one hand, the opposition of science and religion, of scientific and pictorial thinking, intuition and logic, practice and theory; on the other, the diversity of bonds, mediating and intermediate links, as well as the transitions from one form of consciousness to another.

The question of the scientific value of philosophy aroused Hegel’s special interest. In 1802, he emphasised the importance of this question in the Critical Philosophical Journal and discussed the attitude to it on the part of Kant and Fichte. “Philosophy,” wrote Hegel, “since it is to be Ordered Knowledge, cannot borrow its Method from a subordinate science, such as Mathematics.” [1] In his opinion, philosophy was capable of being an objective, conclusive science based on the immanent development of the notion and the absolute method of knowledge. [2] The content of logic as the highest type of philosophical science is its scientific method, the notion of science itself which is its ultimate result, as well as the concept of its subject-matter, thinking in concepts which “is engendered in the course of development of the Science, and therefore cannot precede it”. [3] According to Hegel, the one and only thing for securing scientific progress is understanding that the method of logic is spontaneous development of its content and that its essence is a dialectical, i.e. definite negation. [4]

Having mastered Hegel’s dialectics, Marx and Engels gave a profound comparative analysis of their own and Hegel’s views proceeding from the materialistic idea of the primacy of social being over social consciousness, of the determination of consciousness, its content and structure by the content and structure of the social, practical activity of man. Reuniting dialectics and materialism, Marx and Engels turned dialectics into a real science, and this in the terms that have preserved their validity till nowadays: objectivity, connection with reality and testability of its propositions in practice. Having retained the universality of logical categories and principles, materialist dialectics at the same time got rid of the speculativeness, scholasticism and abstractness which were characteristic of German classical philosophy.

Disclosing the mystified form of Hegelian dialectics in his Economic Manuscripts of 1857–1859, Marx described his own method as being the direct opposite of the Hegelian method. One of the features of Marx’s method, also contrasting with Hegel’s idealistic dialectics, consisted, according to Marx, in that it “leads from abstract definitions by way of reasoning to the reproduction of the concrete situation, ... as a summing-up, a result, and not as the starting point.” [5]

The categories and laws of materialistic dialectics are indeed universal and in this sense irrefutable. Yet their status is entirely different from the status of a priori, absolute Hegelian ideas. The universality of the categories and laws of dialectics interpreted materialistically does not mean that they can be used everywhere, at all times, in all cases and under any circumstances. They are only universal in the sense that they apply to all fields of reality, namely, to nature, society and thinking. When we say that they are universally confirmable, we mean that they are confirmed in all fields of reality. This, and only this is the meaning of “universality” characterising dialectical laws and categories. Of course, such an understanding of universality limits the competence of philosophy which claimed to be the science of sciences by denying it the right to explain or analyse every individual object or phenomena, every relationship or dependence. One can speak of dialectics as the science of sciences in a figurative sense only, meaning that it rises above particulars, trivial problems and petty everyday situations. If Marx and Engels had not risen above their surroundings, they would hardly have managed to discern the essence of capitalism, its basic laws and working of hidden mechanisms behind the Mont Blanc of individual facts. Moreover, had they not risen above reality, they would not have been able to see the outlines of future human society.

This “looking from above” has nothing in common with “looking down” upon something and does not by any means imply a derogatory attitude to specialised sciences, everyday human life and their specific reflection in human consciousness. It is rather an epistemological position indicative of the relative independence of philosophical knowledge and of the specific character of the subject-matter of dialectics as a science. Philosophy and dialectics should be concerned with more general problems than those which come within the scope of special sciences.

It stands to reason that the links and relationships connecting the most general properties of objects and phenomena of reality are different from those connecting specific objects and phenomena. They constitute a specific field of knowledge which cannot be covered in full measure by physics, chemistry, biology, history or any other particular sciences. On the other hand, the tree of science would hardly be able to flourish without its crown transforming the power and tenacity of philosophical ideas into the energy of scientific cognition.

Having preserved the universality of dialectical categories which reflect eternal human problems and link the wonderings of man’s spirit in the depths of outer space, atom or living cell with his earthly existence, Marxism has shown at the same time the real connection of most general philosophical problems with man’s social life, practical activity and problems of special sciences. In that sense Marxism revealed the specific nature of philosophical categories and, consequently, showed the way to test them, i.e. to confirm true ideas and views and to refute false ones. This idea of the unity of the universality (abstractness) of philosophical knowledge and its concreteness was beyond Hegel’s understanding owing to the speculativeness of his philosophy, its detachment from real (material) being rooted in the conception of the identity of being and thinking. This idea, however, is also beyond the comprehension of modern positivism with its fixation on the direct empirical testing of any scientific knowledge and obsession with the struggle against “metaphysics” condemned together with dialectics by the positivist court of “verification” or “falsification”.

The irony consists in that dialectics which had provided the real basis for alliance between philosophy and science way back by the middle of the 19th century has become one of the main objects of positivist attacks against metaphysics and speculativeness. One of the greatest achievements of human mind was treated by the “philosophy of science” equally with religion and other distorted forms of social consciousness. Fighting against dialectics and striving to tear it away from science, positivism was at the same time pretending to give a correct explanation of the nature and essence of scientific cognition, distinguish science from other forms of human activity and delimit religion and mythology. It is this paradox that lies at the root of all the misfortunes of positivism.

The evolution of positivism, which is now almost one and a half century old, has not brought about any appreciable change in its attitude to dialectics. Spencer and Comte underscored the empirical untestability of the categories and laws of dialectics. Mach and Avenarius opposed the dialectics of Marx and Engels even more uncompromisingly. Attempting to disprove dialectics, the logical positivists have seized upon the criterion of verification, and their arguments, if only slightly modified, are now currently used by all modern representatives of the philosophy of science. They allege, for instance, that dialectics is being substantiated by non-scientific methods and that its propositions are just illustrated by examples instead of being mathematically correlated with experience. In support of their charges they usually refer to textbooks on philosophy which sometimes do expound dialectics in an oversimplified didactic manner. Such accusations, however, cannot be taken seriously. Criticism of dialectics requires a far more profound knowledge of the subject than just superficial acquaintance with students’ aids.

The real thrust of positivist criticism consists in the contention that dialectics is nothing but natural philosophy, since it concerns itself with the most general laws of being. A philosopher, according to positivism, has no right to express his views not only on reality as a whole, but even on any of its components. One of the most serious positivist arguments against dialectics is the assertion that it has no empirical content and that its propositions are nonsensical in cognitive terms. According to the positivist critics, this conclusion is borne out by the impossibility of any empirical verification of dialectical statements.

It is commonly argued in present-day positivist literature that dialectics does not disprove anything and that its propositions are universally confirmable, i.e. not falsifiable. In contrast to Russell, Schlick and Wittgenstein who underscored the empirical non-testability, non-verifiability of dialectics and therefore qualified it as metaphysics, Popper and his numerous followers apply a different criterion in the assessment of dialectics. Yet one would vainly expect them to recognise it as the methodology of scientific cognition. Significantly, in Popper’s system which is based on an entirely different and even, in a sense, the opposite approach to the problem of testability of scientific knowledge dialectics, nevertheless, is again classified as “metaphysics”, this time, however, on different grounds: since the “Occam razor” for Popper is falsifiability, he condemns dialectics for universal confirmability or nonfalsifiability of its propositions and principles.

In Popper’s opinion, no facts can be cited which would run counter to the, principles of dialectics, if only potentially. At the same time, dialectical statements are not analytical like those of logic or mathematics. Their fallacy therefore is inherent and can be neither circumvented, nor neutralised. That, according to “critical rationalism”, means that dialectics is just another kind of metaphysics and its statements have but a semblance of empirical content. However, Popper’s prolonged debate with the Vienna school was bound to effect a serious change in his views and to make him reproduce increasingly, though unconsciously, the ideas of German classical and, in particular, Hegelian dialectics. The more anti-positivistic he became, the louder sounded the Hegelian notes in his concept of objective knowledge, “inherent” knowledge, cosmic, physical, biological and cultural evolution. Popper’s militant anti-historicism was giving way to evolutionism, etc. Seeking a clue to Popper’s spontaneous gravitation to Hegelian metaphysics, one should take into account the similarity of the situations in European bourgeois philosophy in the middle of the 20th and the early 19th centuries. Like Hegel’s dialectics born in the midst of the struggle against the mechanical-naturalistic and empirical-phenomenological forms of philosophy, as well as against the reductionist concepts of consciousness, Popper’s evolution towards the dialectical forms of thought takes place in the atmosphere of criticism of the mechanistic dogmas of neopositivism: the static-cumulativistic concept of science, the empirical and inductivist methodology, the physicalist theory of cognition, etc.

Referring to the universality of dialectical categories and laws, representatives of the modern “philosophy of science” speak of the triviality of its conclusions. In their opinion, dialectics applicable to all cognitive situations without exception is nothing but a set of tautological assertions which give no grounds for any differentiations and, consequently, are devoid of analytical possibilities.

They further argue that a philosopher does not base his conclusions on sensory data and does not resort to an experiment. He can only reason within the limits of his professional capability. Hence the conclusion: philosophy must not claim to be anything more than logic. Since formal logic is the development of its own postulates and not related in any way to the outer world, it must not be regarded as knowledge of anything. The logician and, consequently, the philosopher must look after the scientist ensuring that his formal calculations are not nonsensical, but the calculations themselves should be based on linguistic agreements. “For the philosopher, as an analyst,” writes Ayer, “is not directly concerned with the physical properties of things. He is concerned only with the way in which we speak about them... Philosophy is a department of logic. For we shall see that the characteristic mark of a purely logical inquiry is that it is concerned with the formal consequences of our definitions and not with questions of empirical fact.” [6]

Whatever the viewpoints as to the scientific value of various propositions (verification or falsification), the difference between them consists in the adherence to a definite method of comparing such propositions with sensory experience. Laying aside the details, i.e. the question of the methods of checking which are in fact diametrically opposite in each of the concepts and equally one-sided, each concept centres around the problem of testability, at least in principle, of various statements and refutability of false ideas.

It stands to reason that Marxist philosophy also regards the testability of any assertion, i.e. its confirmability or refutability, as the main criterion of scientific knowledge. Marxism holds that the testability of propositions presupposes their concreteness and meaningfulness, and this is just the crux of the matter.

If philosophy is a system of abstract knowledge, the testability of its propositions, in contrast to specialised or positive sciences, is entirely out of the question. Since the categories, laws and principles of dialectics and materialism are indeed expressed in abstract terms, positivism may seem to be justified in asserting that dialectical propositions are nonsensical, unscientific and metaphysical.

True, the categories of materialistic dialectics are the most abstract, i.e. the most general concepts which constitute the initial postulates not only in the system of special knowledge, but also in philosophy itself. “These are the ultimate, most comprehensive concepts,” Lenin wrote, “which epistemology has in point of fact so far not surpassed (apart from changes in nomenclature, which are always possible).” [7] These Lenin’s words characterising the concepts of matter and consciousness are fully applicable to many other categories of dialectics. They cannot be deduced in a purely logical way, à la Hegel, from other concepts—they are abstracted from reality itself and raised to a level of universal philosophical generalisations on the basis of centuries-old human experience and scientific knowledge.

Indeed, if we identify the concrete with sensory experience and regard as concrete an individual object or a phenomenon given us in direct sense perceptions dialectics will inevitably appear as an abstract science, a field of abstract knowledge free from any sensory experience and concreteness since it is far removed from the sensuous world and is least of all concerned with individual phenomena and objects concentrating primarily on their general properties and relations. It is just this understanding of the abstract and the concrete in which the former represents the universal properties and relations, and the latter, the sensually perceived individual objects, that is prevalent in literature and underlies the attempts to counterpose philosophy and special sciences.

Before we proceed to philosophical categories, let us have a closer look at the most concrete, at first sight, knowledge, the knowledge of what is given us in everyday sensory experience, and see how concrete and, consequently, testable it is.

What can be said about sensory experience as the primary source of our knowledge? If we are to rely upon it for its critical and informative values as proposed by positivism, it must be the real standard of clarity and we should have no doubt as regards its content or possible limits. Yet the very first pages of Hegel’s Phenomenology of Spirit show that there is nothing more obscure than sensory experience. If we want to get pure sensory experience and abstract from all rational elements, all “structures” of the mind, we shall find ourselves in possession not of the richest, but of the poorest content conceivable. We shall have to throw away all universal or rational forms, all categories such as “quality”, “contradiction”, “necessity”, “matter”, etc. in order to find absolutely possible pure “this”, “here”, “now”.

Having arrived at this point, we shall realise that instead of a well of knowledge we have got an iridescent soap bubble ready to burst under the slightest whiff of scientific air and absolutely empty at that. What we find, writes Hegel, is in itself unstable and indefinite, since even with a minor change of our view or attention we find a different “this—here—now.” However, even these categories must preserve some remnant of the abstract, if they are to have any sense at all. “This”, “here” and “now” turn out to be the least definite of all categories when we attempt to define or fix them with the help of experience. They acquire their stable meaning due to the work of mind only.

Hegel’s concepts of the abstract and the concrete are much more refined and promising, if only for the fact that he does not necessarily connect the concrete with sensual perception. A “murderer” is an abstract definition for a crowd of idlers not because it is a legal notion abstracted from man’s other definitions (though it is also true), but mainly because he ceases to be anything else but a murderer for an onlooker watching the execution. “A handsome murderer? Can one think so badly, can one call a murderer handsome?” [8] His personality with all the richness of his life, his appearance, upbringing, etc. are all squeezed into a single definition severing all other ties and relations with the world. The abstract for Hegel is the separate, isolated, alienated from the multitude of ties and relations of an object. By contrast, the concrete is the richness of the fully reproduced properties and qualities in their totality. According to Hegel, a wise judge of human heart thinking in concrete terms will consider the entire course of events shaping the criminal’s character, trace the influence of bad relations between his father and mother on his life and his upbringing, reveal, perhaps, the injustice or cruelty to which he was exposed, etc.

Hegel evidently intended to reconcile society with itself, the society “which, on the one hand, disregards abstract thinking without suffering the pangs of remorse, and, on the other, feels at heart certain respect for it as for something elevated, and avoids it not because of contempt for it but because of glorification, not because it seems something commonplace but because it is taken for something notable or, on the contrary, for something special”. [9]

Yet Hegel’s irony which, for that matter, permeates his entire article, is too obvious to make the opponents of the abstract more tolerant. The examples of the average man’s concrete thinking displayed by Hegel are too unattractive to make his eulogy of concrete thinking flattering for the champions of empirical concreteness. Here Hegel hasn’t got the slightest chance to win their sympathy. It is the more regrettable as even this publicistic article is, in fact, very instructive. Hegel convincingly shows that what appears at first sight very concrete knowledge with lots of down-to-earth and juicy details turns out to be extremely incomplete, i.e. abstract.

True, Hegel hardly shows here the depth of the abstract, the concreteness of general determinations. The abstract and the concrete do not yet merge in organic synthesis. They are still held apart by the idea that knowledge can be concrete and abstract and that abstract knowledge can pass into concrete knowledge through ever more substantive determinations. We should not, however, demand too much from Hegel. What he said gives grounds for further inferences and suggests, if only implicitly, new ideas. Hegel is known to be helpful in overcoming Hegel and in enabling his successors to open up new horizons, standing on his own shoulders.

Hence, none other than Hegel enables us to make the first critical remark about positivism: the highest positivist criterion of meaningfulness and scientificity proves itself to be extremely indefinite and badly needing clarification. Yet neither definiteness, nor clarity can be borrowed from the formal logic which is nothing but a set of conventional rules for formulating statements. Of course, sensory experience can play the part of a cognitive method, but it can only be defined and harmonised within a broader rational system, such as the one conceived by Hegel, but not within sensory experience itself or the logical syntax. Positivism strives, so to speak, to freeze arbitrarily the cognitive method at one of the levels, important though it may be.

Since the criterion of sensory experience is itself uncertain, one should not be surprised at the controversies flaring up now and again within positivist philosophy over the nature of experience. Experience was first believed to consist of fragmentary sensory data. Later it became clear that such fragments were themselves abstractions singled out by the mind from more concrete and continuous whole. What were then the pure sense data? Were they to include relations having different abstract components?

Nor was it clear which categories expected to be discovered within the sphere of pure experience were genuine, and which were purely logical, i.e. verbal structures. More, was sensory experience to be regarded as the manifestation of something called “qualities” (if this term had any meaning at all at the given level) and wasn’t even the most primitive experience mingled with our conviction surfacing, for instance, in the vagueness of assertions and statements on facts and situations? Finally, whence the assurance that sensory experience was to be placed in the foreground?

It is again Hegel who helps us reveal this important omission of positivist philosophy. The mind is denied the ability to comprehend reality, since every statement about reality must, by force of its synthetic nature, express pure chance, and the mind does not produce anything but only elaborates the conclusions obtained from clear verbal statements. For Hegel, statements of chance represent but a moment which is barren of any thought and signifies that mind has already completed its work.

Positivism, on the contrary, regards as meaningful only those statements which relate to accidental (or probable) facts. Yet to point out a fact does not mean to comprehend it. A synthetic statement a posteriori is nothing but a record of what has occurred, but it has no explaining force. Such statements cannot become explanatory through generalisation processes. They remain synthetic irrespective of whether they refer to one, some, most or all objects. A statement which is now called law remains a simple assertion that something is accidental and gives no understanding of the causes of the given occurrence.

It is obvious that the process of generalisation enhances the “force of prediction”. To speak of the object as a whole is to give a more reliable prediction of the future state of affairs. Yet the ability for prediction is something different from comprehension. Even if we eventually succeeded, through hard work, in obtaining generalisations covering the broadest possible field of events and were able to predict the course of every experiment, we would not take a single step towards understanding any of them.

The function of the mind, according to Hegel, is neither the singling out of tautological statements, nor the generalisation of synthetic statements of facts. Its function is comprehension. Rational comprehension for Hegel results from at least two factors: the ontological status of the mind and the impossibility to find something which can be completely determinable or completely comprehensible. The first factor prevents logic from being conventional and purely verbal, the second factor does not allow it to bog down at the very beginning.

One of the obvious meanings of the concept “concreteness” is that our knowledge reflects empirical objective reality and that every notion, judgement or scientific theory has quite definite objective content which we call empirical. The empirical concreteness of our knowledge is its conformity with sensory experience. Our everyday experience, practical activity, the experimental side of scientific cognition evidently possess the highest degree of empirical concreteness. But does it mean that empirical concreteness is not inherent in the theoretical knowledge of special sciences? Besides, can we make a categorical assertion that the knowledge resulting from empirical investigation is really the most concrete knowledge? It is indeed concrete in the sense that it is close to reality and rich in detail and colour. Yet one cannot help feeling that such knowledge of details can very easily turn into a useless toy if it fails to distinguish the main, the significant, the essential, the necessary.

The empirical knowledge of separate isolated facts permits tearing out individual parts or features of a whole and turning them into an absolute, a senseless abstraction. If the concrete is understood as the direct connection with the objective world, as the exact reproduction of sensually perceived properties and sides of an object, such knowledge will be the most concrete. On the other hand, if concreteness is understood as the fullness of all determinations of an object or a phenomenon, as a unity in the diversity or a diversity in the unity, such knowledge should be regarded with good reason as abstract. Conversely, if abstract knowledge is characterised by the separation, isolation of one or another element from the totality of other determinations, empirical knowledge which does not reveal all links and relations of a given object with the multitude of other objects can also be called abstract, sometimes even in the worst sense of this word.

A purely empirical idea of a tree growing under my window and having, for instance, slightly drooping branches, a trunk reaching the height of the first floor and covered with grey-green bark, with light-green buds on its branches the size of a wheat grain, etc. will be an abstract description despite the fact that I could add to it lots of such details which are known to no one but myself, since this tree was and will hardly be interesting for anyone as a possible object of an empirical description.

Hence, the concepts of the concrete and the abstract themselves need a serious analysis. A detailed description of a tree growing in front of my window and presented to me in all its sensual concreteness turns out to be quite abstract since my detailed description based entirely on the sense-perceptions of the colour of the bark, buds, the shape of the crown, the size of the trunk, etc. will hardly be helpful in determining its species. Any student of biology will find my description non-scientific and abstract as it covers millions of trees in the middle part of Russia. Hence, an empirical description can be justly regarded as abstract, arbitrarily subjective, non-scientific etc. since it does not permit distinguishing with certainty one object from a multitude of others.

As we see, even a very detailed description of the external side of objects and phenomena can .far from always be regarded as concrete knowledge without any reservations. It moans that the direct relationship between knowledge and reality, i.e. the sensual basis of knowledge, is not yet sufficient to make it concrete. Such knowledge is still incomplete and inaccurate since it reflects but partially the real links and relations between a given object and a multitude of others. As to the reflection of the internal properties,; bonds, contradictions and laws governing the development of this object, such knowledge is even less satisfactory. Consequently, the knowledge of separate observable objects and phenomena, their properties and sides can be regarded both as concrete, in the sense that it is directly related to reality, and as abstract (theoretically abstract), in the sense that it does not reveal the latent processes and internal laws and does not single out the main, the essential.