How do we acquire knowledge? Is there a real world beyond our senses? And if so, what is our relation to it? In this important theoretical contribution, editor Alan Woods mounts a defence of materialism against idealism and the obscurantist, postmodernist subjectivism popular on university campuses today.

Joseph Dietzgen once said that official philosophy was not a science, but a safeguard against socialism. He was quite right. No matter how indignantly they deny it, professional philosophers have been enlisted by the defenders of the status quo as allies in the struggle against Marxism. This was particularly blatant in the period of the Cold War, when the CIA used philosophy and art as weapons against communism, but it remains true today.

Ever since Marxism emerged as a significant force, challenging the existing order, the establishment has been in a perpetual state of war on every aspect of Marxist ideology, starting with dialectical materialism. The very mention of Marxism is guaranteed to provoke a knee-jerk reaction in such circles. ‘Out of date’, ‘unscientific’, ‘disproved long ago’, ‘metaphysics’, and all the rest of the threadbare and tiresome litany of reaction.

Not only are Marx and Engels personae non grata in the hallowed halls of the philosophy departments, but poor old Hegel, who was once hailed as the philosopher’s philosopher par excellence, is subjected to a quite shameful conspiracy of silence, or worse.

This situation is not only a reflection of ignorance and prejudice (though there are plenty of both). Powerful material interests are at stake, which soon convince all but the bravest souls that it is not wise to offend those who provide the grants and control academic careers.

This text also appears as an introduction to our new edition of Lenin’s classic book on Marxist philosophy, Materialism and Empirio-criticismThe book is available to buy now here! It is also available in ebook format.

It is also evident that the postmodern academic gang do not like to be reminded of the fact that there was once a time when philosophers actually had something profound and important to say about the real world.


Already in What Is to Be Done? Lenin pointed out:

Without revolutionary theory there can be no revolutionary movement. This idea cannot be insisted upon too strongly at a time when the fashionable preaching of opportunism goes hand in hand with an infatuation for the narrowest forms of practical activity. (V. I. Lenin, What Is to Be Done, Wellred Books, 2018, p. 26.)

He added that “the role of vanguard fighter can be fulfilled only by a party that is guided by the most advanced theory.” (Ibid., p. 27.)

And one of the most important contributions to Marxist theory is undoubtedly Materialism and Empirio-criticism.

Lenin began writing this Marxist classic in February 1908. This was at the height of the period of reaction following the defeat of the Moscow uprising in December 1905. The working class was exhausted. The peasant revolt upon which Lenin placed his hopes for a revolutionary revival came too late. The initiative passed to the tsarist regime, which went on the offensive.

A wave of black reaction followed, lasting several years. Mass arrests, summary executions, and the merciless crushing of any opposition decimated the movement. The Marxists (then known as Social-Democrats) were subjected to the most brutal persecution. Their leaders hunted down, imprisoned and sent to Siberia, or executed. Thousands more were murdered without trial.

materialism cover small
Lenin began writing this Marxist classic at the height of
the period of reaction following the defeat of the
Moscow uprising in December 1905

This defeat had a profoundly demoralising effect on the movement, and especially on the intellectuals who had sympathised with the revolution when it was in full tide, but began to abandon it as soon as the reaction set in. A mood of pessimism swept through the petty bourgeoisie.

This found its expression in a general feeling of hopelessness, a tendency to abandon the class struggle and look inwards, to seek new ideas and panaceas, including mystical and semi-religious ideas (‘God building’). It is in this context that one must see the real significance of Lenin’s fight against philosophical revisionism.

It was about this time that the subjective idealism of Richard Avenarius and Ernst Mach became fashionable among a layer of the intelligentsia in Russia. It corresponded closely to the prevailing mood of dejection, pessimism, and mysticism.

The socialist movement was not immune to this development, and a layer of it began to make concessions to Machism. This was part of the process of counter-revolution in the sphere of ideas.


The same pattern can be observed time and again in the wake of defeated revolutions. As soon as the revolutionary movement encounters setbacks, we see a long line of depressed intellectuals, falling over themselves, one after another, in an indecent haste to abandon the movement and retire to the safety of their studies.

The intelligentsia provides a fairly accurate barometer of the shifting moods of the petty bourgeoisie. As an intermediate stratum standing between the proletariat and the bourgeoisie, they are an organically unstable social layer, constantly oscillating between the two great poles in society.

Insofar as the intelligentsia is capable of gravitating towards the working class and revolutionary socialism, it always proves to be a highly unstable, vacillating, and unreliable ally. When the working class moves in a revolutionary direction, a section of the petty-bourgeois intellectuals can experience ecstatic moods of enthusiasm, but these mood swings can very soon turn into their opposite.

Losing its faith in the strength of the working class, the intelligentsia gives in to the pressure of reaction and moves to the right. The ideals of collective struggle give way to a search for individual solutions. Subjectivism, relativism, and agnosticism, in other words, philosophical idealism, begin to gain ground.

They invent all kinds of fancy ideas to explain the causes of defeats. They always blame the working class for their own failures. And they invariably start chattering about the need for ‘new ideas’, and ‘freedom to criticise’ in order to put an end to the ‘suffocating orthodoxy’ (Marxism) that, in their view, has let them down.


In Russia, between 1906 and 1908 a series of books and articles appeared, written by Alexander Bogdanov, Anatoly Lunacharsky, and V. A. Bazarov, as well as other leftist intellectuals such as the Menshevik Pavel Yushkevich and the main theoretician of the Socialist-Revolutionary Party, Viktor Chernov. The main thrust of these works was that Marxism was ‘antiquated’. It needed to be updated by infusing it with the ‘new’ discoveries made by Mach and Avenarius.

But Marxism is a unified and harmonious world view. It is not a collection of good ideas, each of which can be changed at will. These so-called ‘minor adjustments’ amounted, in practice, to a complete negation of Marxism and its materialist philosophy.

Not only were these ideas fundamentally wrong, but they were beginning to find an echo in the ranks of the Bolsheviks – even at the leading level. Bogdanov was at this stage one of the most prominent people on the Bolshevik central committee and a member of the editorial board of the Bolshevik paper, Vperyod. In the period prior to the 1905 revolution, he and others who followed his philosophical line had played a prominent role. He was also building himself a position as an expert on the question of philosophy.

However, being well read in the field of philosophy does not necessarily mean that one understands it. Bogdanov and his followers repeatedly revealed that their understanding of Marxist theory was narrow and quite superficial, tending to rigid schemas and formulae. They displayed a complete lack of understanding of Marxist philosophy: the dialectical method was quite alien to them, a fact that was later to lead them into a series of ultra-left errors in the field of tactics.

Like other revisionists before (and since), the Bolshevik Machists raised the cry for the ‘freedom to criticise’. They insisted that they were not against Marxism, but merely wished to ‘bring it up to date’, in line with the ‘latest discoveries’ of science and philosophy.

But this was merely a ruse and a distraction from the fact that they were drifting away from Marxism and that they wanted to drag the party along with them. Lenin was very clear about this:

Comrade Sazhin… demands that ‘Party members’ must be ‘ensured’ ‘complete freedom for their revolutionary and philosophical thought’.

This slogan is thoroughly opportunist. In all countries this kind of slogan has been put forward in the socialist parties only by opportunists and in practice has meant nothing but ‘freedom’ to corrupt the working class with bourgeois ideology. ‘Freedom of thought’ (read: freedom of the press, speech and conscience) we demand from the state (not from a party) together with freedom of association. The party of the proletariat, however, is a free association, instituted to combat the ‘thoughts’ (read: the ideology) of the bourgeoisie, to defend and put into effect one definite world outlook, namely, Marxism… Some Vperyodists long with all their heart and soul to drag the proletariat back, to the ideas of bourgeois philosophy (Machism), while others are indifferent to philosophy and merely demand ‘complete freedom’… for Machism. (V. I. Lenin, ‘The Vperyod Faction’, 1910.)

The bible informs us that there is nothing new under the sun. And in reality, there was nothing new, either in the ideas of Mach and Avenarius, nor in the Russian Machists’ claims to possessing an update to Marxism. Marx and Engels waged many struggles against idealist revisionism, the most famous case being Engels’s polemic against Eugen Dühring.

Throughout the history of the revolutionary workers movement, every now and then, some clever people thrust themselves forward with claims that they wish to bring Marxism up to date. Bogdanov and his co-thinkers were just such people. In practice, these elements reflect the pressures of alien classes.

The working class does not exist in a vacuum; it is surrounded by other classes and social layers, whose class outlook can find a reflection within the workers movement. The class struggle is therefore not only an economic and political struggle, but just as importantly a philosophical struggle, as Lenin repeatedly emphasised.


A A Bogdanov Image public domain
Lenin never hid his differences with the likes of Bogdanov on the
question of philosophy / Image: public domain

Lenin had never hidden his differences with Bogdanov on the question of philosophy. But for several years, he was willing to collaborate with him and to put his other skills to the use of the party. However, as soon as Lenin became aware of the systematic attempts to undermine the philosophical basis of Marxism, he declared war on the Machists. He embarked on a determined struggle to defend the fundamental ideas of Marxism against revisionism. The highest expression of this struggle was the publication in 1909 of Materialism and Empirio-criticism. At the time, Lenin wrote to Maxim Gorky, who was a close friend of Bogdanov as well as Lunacharsky and sympathised with some of their views:

Now the Studies in the Philosophy of Marxism [A series of articles arising from a Symposium organised by Bogdanov and his allies – AW] have appeared. I have read all the articles except Suvorov’s (I am reading it now), and every article made me furiously indignant. No, no, this is not Marxism! Our empirio-critics, empirio-monists, and empirio-symbolists are floundering in a bog. To try to persuade the reader that “belief” in the reality of the external world is “mysticism” (Bazarov); to confuse in the most disgraceful manner materialism with Kantianism (Bazarov and Bogdanov); to preach a variety of agnosticism (empirio-criticism) and idealism (empirio-monism); to teach the workers “religious atheism” and “worship” of the higher human potentialities (Lunacharsky); to declare Engels’ teaching on dialectics to be mysticism (Berman); to draw from the stinking well of some French ‘positivists’ or other, of agnostics or metaphysicians, the devil take them, with their “symbolic theory of cognition” (Yushkevich)! No, really, it’s too much. To be sure, we ordinary Marxists are not well up in philosophy, but why insult us by serving this stuff up to us as the philosophy of Marxism! I would rather let myself be drawn and quartered than consent to collaborate in an organ or body that preaches such things. (V. I. Lenin, ‘A Letter to A. M. Gorky’, 1908.)

This was not at all a debate on obscure philosophical doctrines. It was a struggle for the soul of the revolutionary movement. Lenin was very clear as to what the Machian attack effectively meant: “…we have among us people who would have us regard them as Marxists, yet who bring to the masses a philosophy which comes very close to fideism.”[1] (V. I. Lenin, Materialism and Empirio-criticism, Wellred Books, 2021, p. 55.)


The main outline of the Marxist philosophy (dialectical materialism) was explained by Friedrich Engels in Anti-Dühring and Ludwig Feuerbach and the End of Classical German Philosophy. Here Engels writes that the fundamental philosophical trends are materialism and idealism. In his book, Lenin explains the difference between these philosophical trends:

Materialism regards nature as primary and spirit as secondary; it places being first and thought second. Idealism holds the contrary view. This root distinction between the “two great camps” into which the philosophers of the “various schools” of idealism and materialism are divided Engels takes as the cornerstone, and he directly charges with “confusion” those who use the terms idealism and materialism in any other way. (Ibid., p. 74.)

Lenin’s struggle was first and foremost to bring to light the fundamental distinction between idealism and materialism and to introduce clarity as to the real significance of Machism, which in effect amounted to nothing but a form of idealism. He mercilessly attacked the Russian Machists for their “mutiny on one’s knees” and demanded that they come to the fore “to ‘settle accounts’ openly, explicitly, resolutely and clearly with the views they had abandoned”. (Ibid., p. 2.)

As is usually the case with revisionists, Bogdanov and Lunacharsky tried to disguise their break with Marxism by a series of dishonest tricks and ruses. But Lenin mercilessly tore away the mask to reveal the reactionary idealist content that lay beneath.

Step by step, layer by layer, this book exposes idealism in all its guises. In the same thorough way that Engels answered the ideas of Dühring, Lenin quotes at length from the philosophical writings of the Russian Machists as well as the writings of other scientists and philosophers.

Some people complain that Lenin’s book makes for heavy reading. Maybe so. But the only way in which one can answer false ideas, without being accused of distortion or misunderstanding, is precisely to quote what is written, word for word. This is what Lenin does, and nobody can complain that he does not treat his opponents fairly.

But for that very reason, he is entitled to pass the harshest judgement upon them – which he does not hesitate to do. He calls them blockheads and other things that one is not accustomed to hearing in university seminar rooms. But as we know very well, there is no shortage of blockheads there either, even if no-one dares to call them by their right name.

Lenin’s aim was very simple: to bring out in the open the real difference between Marxist dialectical materialism and the subjective idealism of the Machists. In that, he succeeded brilliantly.

Analysing the different shades and expressions of Machism internationally, Lenin stressed that in “every philosophical question raised by the new physics, we [trace] the struggle between materialism and idealism.” (Ibid. p. 283.) And he showed that:

Behind the mass of new terminological devices, behind the litter of erudite scholasticism, we invariably discerned two principal alignments, two fundamental trends in the solution of philosophical problems. Whether nature, matter, the physical, the external world should be taken as primary, and consciousness, mind, sensation (experience – as the widespread terminology of our time has it), the psychical, etc., should be regarded as secondary – that is the root question which in fact continues to divide the philosophers into two great camps. (Ibid.)

So seriously did Lenin take this ideological struggle that he was prepared to break with the entire leadership of the Bolshevik faction on these issues. The split occurred in 1909, when Lenin chose to break with Bogdanov and Lunacharsky rather than make the slightest concession to their revisionism in philosophy and their sectarian formalism and ultra-left politics. This was after almost two years of internal struggle. However, by the time the split occurred, Lenin had succeeded in winning over the majority of the party to the position of dialectical materialism, and it was Bogdanov and the Machists who left.


Materialism rejects the notion that mind and consciousness is something separate from matter. Thought is merely the mode of existence of the brain, which, like life itself, is only matter organised in a certain way. Mind is what we call the sum total of the activity of the brain and the nervous system. But, dialectically, the whole is greater than the sum of the parts. This view corresponds closely to the discoveries of science, which is gradually uncovering the workings of the brain and revealing its secrets.

By contrast, idealism persists in presenting consciousness as a ‘mystery’, something that we cannot comprehend. It mystifies the physical and causal link between the thinking mind and the human body. This so-called mind-body problem arises because of the fact that mental phenomena appear to be qualitatively different from the physical bodies on which they appear to depend. Consistent materialism, however, maintains that mind and body are of one substance.

George Berkeley by John Smibert Image public domain
Lenin clearly shows the relationship between idealist philosophy
and clericalism, quoting at length from the works of Bishop
Berkeley and other protagonists of the Church
/ Image: public domain

The idealist trend in philosophy is at least as old as Plato and Pythagoras, who saw the physical world as a poor imitation of the perfect Idea (Form), which existed before the world came into existence. This is a view that fits in very nicely with the vested interests of the religious lobby, which is highly vocal in defending whatever can still be defended of the primeval prejudices about the soul, a life after death, and all the other religious rubbish that has accumulated in the human brain from the most remote and primitive times. Hiding behind the respectable façade of philosophical idealism is religion and superstition. The Immaculate and Eternal Soul was supposed to be locked up inside the grubby, imperfect and short-lived material body, longing for release at the moment of death, when we ‘give up the ghost’ and float up to Paradise (if we are lucky).

Throughout history religion has been a barrier to the advance of science. The Church is hostile to the advance of knowledge because every step forward in science removes yet another basis for religious superstition. Religion is based on blind faith, not knowledge. It relies on the fear of the unknown, and therefore the unknown is its greatest ally. That is why all religions are based on mysticism, obscurantism, miracles, etc.

The Church attempted to block the path of progress and science with the fires of the Inquisition, but to no avail. The sixteenth and seventeenth centuries were a period when philosophy still retained all its vigour. Its ideas were relevant, in a way they no longer are. Philosophy really was science and science philosophy. In this brave new world, it seemed that God had no place.

Isaac Newton, a Theist, provided God with a role in his clockwork universe: that of providing it with an initial impulse. But after this elementary task, there was really nothing else for the Almighty to do for the rest of eternity. The new philosophy provided a basis for atheism, and the defenders of the Faith were well aware of it.

The most outspoken opponent of materialism at the time was George Berkeley (1685-1753). Berkeley was an Englishman who became bishop of Cloyne in Ireland. As the final and definitive answer to materialism, he argued that matter itself did not exist, and that the world only came into existence when it was being observed. He attacked the concept of matter on the grounds that it was so full of contradictions as to be useless in the search for knowledge.

Lenin clearly shows the relationship between idealist philosophy and clericalism, quoting at length from the works of Bishop Berkeley and other protagonists of the Church:

“For as we have shown the doctrine of Matter or corporeal Substance to have been the main pillar and support of Scepticism, so likewise upon the same foundation have been raised all the impious schemes of Atheism and Irreligion… How great a friend material substance has been to Atheists in all ages were needless to relate. All their monstrous systems have so visible and necessary a dependence on it, that when this cornerstone is once removed, the whole fabric cannot choose but fall to the ground, in so much that it is no longer worth while to bestow a particular consideration on the absurdities of every wretched sect of Atheists.” (Ibid., p. 12.)

As we can see from the above, Bishop Berkeley developed his subjective idealism as an answer to what he saw as the materialist atheism of Newton and the other scientists of his day. He rejected the infinitesimal calculus of Newton and Leibnitz because the recognition of the infinite divisibility of ‘real space’ contradicted the basic postulates of his philosophy.

He cleverly used the arguments of empiricism to refute materialism and defend religion. He did this quite deliberately in order to combat the atheism that he felt – quite correctly – was gaining ground as a result of the progress of science.

Bishop Berkeley showed very ingeniously that the logic of empiricism, when taken to the extreme, leads us to the conclusion that we cannot prove the existence of the physical world independent of our (my) senses. Proceeding from the undeniable proposition ‘I interpret the world through my senses’, he drew the conclusion that I cannot know anything except my sensations.

In place of Locke’s statement “Nihil est in intellectu quod non sit prius in sensu” (“Nothing is in the mind that was not first in the senses”), Berkeley asserted: “esse est percipi”, that is, “to be is to be observed”. Things can only exist insofar as they are perceived. Therefore, it is impossible to say with any certainty that the world exists outside my sense perception. This philosophical doctrine, where the subject determines being, is called subjective idealism.

But there was a fatal flaw in Berkeley’s case. The inescapable logic of his argument is solipsism – only I exist. Since my sense perception determines being, hence I cannot prove the existence of anything but myself. But if that is the case, where does God come into it? Surely, he too must be just a figment of my imagination – just another ‘sense content’!

Berkeley was no fool. As we shall see, he was well aware of this inconvenient fact, which he attempted to get around by positing the existence of a multiplicity of spiritual substances and also a “cosmic mind” (God).

This dilemma was the subject of an amusing Limerick, which goes as follows:

There was a young man who said “God

Must find it exceedingly odd

To think that the tree

Should continue to be

When there’s no one about in the quad.”


Dear Sir: Your astonishment’s odd;

I am always about in the quad.

And that’s why the tree

Will continue to be

Since observed by, Yours faithfully, God.

(R. Knox, God in the Quad)

The poem is amusing and ingenious, but only of serious interest to those who feel the need to invoke an invisible Spirit to prove that the tree we look at really exists. Before we take such a leap of judgment, however, what needs to be demonstrated is not the reality of a tree, which we can all see, but of an invisible Spirit, which, by definition, we cannot.


The theory of knowledge – also known as epistemology – occupies a central place in the history of philosophy and it lies at the heart of the difference between philosophical materialism and idealism.

The so-called subject-object problem has occupied the attention of philosophers for centuries. It is concerned with the analysis of human experience, and of what within experience is ‘subjective’ and what is ‘objective’.

How do we know the world ‘outside’ us? The question is posed in terms of a dichotomy:

a) the thinking ‘subject’ (‘I’), and

b) the object of thought (the ‘external’ world).

This question was already raised in the writings of Aristotle, but in the modern – epistemological – sense, it dates from the 17th century, raised by bourgeois philosophers such as René Descartes and John Locke. Descartes, who was an idealist, introduced the notion of dualism. Descartes’ dualism depicts mind and body as two entirely separate substances. Hence the ‘dual’ element.

The mistake is to treat consciousness as a ‘thing’, an independent entity, separate and apart from human sensuous activity. The insurmountable difficulty with dualism is this: if the mind is entirely different to the physical body, how can they interact?

We now know what Descartes did not know about the workings of nature, the world of molecules, atoms, and subatomic particles, of the electric impulses that govern the workings of the brain. In place of a mysterious soul, we are beginning to acquire a scientific understanding of how the human body and brain function.

The discoveries of modern science have forever banished the notion of consciousness as an independent ‘thing’. Yet, strange as it may seem, this mystical nonsense does not lack advocates even in the 21st century.


The first question is ‘what’ is known. The second problem is that of ‘how’ do we know what we know. That is essentially what epistemology attempts to answer.

It is an elementary proposition that I interpret the world through my senses. This assertion, in reality, is a pure tautology, inasmuch as I cannot possess any knowledge of the world without eyes, ears, hands, and brain. Subjective idealism interprets this to mean that, in reality, I can have no real knowledge of the world outside of my own sensations.

Friedrich Engels Image public domain
Dialectical materialism sets out from the proposition that the objective
world exists independently of the subject, but the two form part of a
dialectical unity / Image: public domain

To use the expression of the logical positivist philosopher A. J. Ayer, all I can know are my “sense contents”.

The so-called problem of knowledge only arises when consciousness is regarded:

a) as something separate from a physical body, and

b) as something separate from the material world.

In reality, subjective idealism and philosophical dualism are merely an idealisation of the rigid separation between mental and manual labour. In effect, the mystification of human thought is carried to such an extreme that it is alleged that only my thought is real. ‘This side’ is juxtaposed to ‘That side’ as if the two were separated by an impenetrable barrier.

Dialectical materialism sets out from the proposition that the objective world exists independently of the subject, but the two form part of a dialectical unity. Consciousness is not a ‘wall’ separating subject and object, but a bridge connecting the two. The subject is itself an object, insofar as humans are subject to the objective laws of nature and society.

But through their subjective activity, humans can and do interact with the objective world that surrounds them, profoundly modifying not just nature but also society.

Thus, subject and object are not eternally fixed and immutable antitheses, but can and do change places, the one passing into the other. They constantly react on each other, as a result of humankind’s socio-economic practice. It is practice, not passive contemplation, through which men and women have constantly transformed their environment, and thereby have transformed themselves.

This is not necessarily related to thought at all, since most of the modifications have taken place without any planning or conscious thought whatsoever. These transformations are the result of human sensuous activity: human labour, from the work of primitive stone tools to the activity of nuclear reactors.


Human activity enables us to understand the world we live in and its laws, and therefore ultimately enables us to master these laws, rise above them and attain true freedom, which is the recognition (understanding) of necessity.

We do not think only with a brain, but with our whole body. Therefore, a baby begins to understand the material world by the simple procedure of putting it in its mouth and trying to eat it. In the words of Goethe, “in the beginning was the deed”.

But thinking must be seen, not as an isolated activity (‘the ghost in the machine’) but as part of the whole human experience, of human sensuous activity and interaction with the world and with other people. It must be seen as part of this complex process of permanent interaction, not as an isolated activity that is mechanically juxtaposed to it.

When we say that all knowledge is based on experience, this does not at all mean my personal experience, but includes all the collective experience of humans over a period of hundreds of thousands of years.

The world existed long before humans or any other life form was present to observe it. Animate matter (life) arose naturally from inanimate matter. At a certain point, simple one-celled creatures evolved into more complex life forms, invertebrates into vertebrates, and so on. The further development of a central nervous system developed into a brain, and eventually into the human brain and human consciousness. We are matter that has become conscious of itself.

This explanation is corroborated by all the discoveries of science. But for idealism this remains a closed book. All forms of idealism are inseparably linked to religion and invariably lead back to religion.

In relation to this, Trotsky wrote shortly before his assassination:

“We do not know anything about the world except what is provided through experience.” This is correct if one does not understand experience in the sense of the direct testimony of our individual five senses. If we reduce the matter to experience in the narrow empirical sense, then it is impossible for us to arrive at any judgement concerning either the origin of the species or, still less, the formation of the earth’s crust. To say that the basis for everything is experience is to say too much or to say nothing at all. Experience is the active interrelationship between subject and object. To analyse experience outside this category, i.e., outside the objective material milieu of the investigator who is counter-posed to it and who from another standpoint is a part of this milieu – to do this is to dissolve experience in a formless unity where there is neither object nor subject but only the mystical formula of experience. “Experiment” or “experience” of this kind is peculiar only to a baby in its mother’s womb, but unfortunately the baby is deprived of the opportunity to share the scientific conclusions of its experiment. (L. Trotsky, Writings of Leon Trotsky: 1939-1940.)

It is precisely this collective experience that enables us to make sense of what we know of the world, to make accurate and scientific judgements of the information we receive through our senses and draw the inferences that permit us to make correct predictions about the physical world and society.

Knowledge is therefore not confined to the narrow sphere of individual sense perception, since, to understand the limited information derived from my individual experience, I must rely on a vast amount of information that is transmitted from generation to generation in the form of theoretical abstractions.

The very word abstraction comes from the Latin “derived from”, which shows very clearly how all theoretical generalisations (including the most abstract mathematical formulae) are ultimately derived from the observation of the physical world. We count up to ten, not because the decimal system is superior to any other (it is not) but only because we have ten fingers which we still tend to count to work out simple sums.

Once these abstractions are established, they seem to take on a life of their own and provide a powerful tool for understanding the world and an indispensable instrument for the advancement of science, which represents the dialectical unity of deduction and induction, of theory and practice, of scientific hypotheses with observation and experiment. One thing is unthinkable without the other.


The progress of science has provided the answers that explain the physical origin of consciousness. We know how organic matter (life) arises naturally from inorganic matter. Even the earliest forms of life display signs of sensibility. Irritability, which is precisely the way in which living organisms react to the physical stimuli that come from the external world, is present in all forms of life.

Even in plants we find a similar phenomenon, as when flowers turn to face the sun. When they do this, what are they reacting to? Not ‘sense contents’, because plants do not have senses as such. They are reacting to external stimuli from the physical world. It is the same for all living organisms. In every case they are reacting to external stimuli.

We now know that the action of nerve cells is both electrical and chemical. At the ends of each nerve cell there are specialised regions, the synaptic terminals, which contain large numbers of tiny membranous sacs that hold neurotransmitter chemicals. These chemicals transmit nerve impulses from one nerve cell to another. After an electrical nerve impulse has travelled along a neuron, it reaches the terminal and stimulates the release of neurotransmitters from their sacs.

The neurotransmitters travel across the synapse (the junction between the neighbouring neurons) and stimulate the production of an electrical charge, which carries the nerve impulse forward. This process is repeated over and over again until a muscle is moved or relaxed or a sensory impression is noted by the brain. These electrochemical events can be considered the ‘language’ of the nervous system, by which information is transmitted from one part of the body to another.

This scientific explanation immediately does away with the mystical-idealist view of thought and consciousness as something mysterious and inexplicable, something divorced from the normal workings of nature and other bodily functions. These, in turn, are formed and developed by constant interaction with the material environment through collective social labour.

Evolution has developed different ways of reacting to the physical environment in order to ensure the survival of the individual (food) and the species (reproduction). Just as we share some genes with even the lowly bacteria, so we share this common facility. But in humans this bare potentiality has evolved into something on a qualitatively different level to other animals.

It may be said that there is something resembling consciousness in cats, dogs, horses, and other higher mammals. Certainly, experiments on chimpanzees have suggested that they may possess something akin to self-consciousness. In fact, it may even be possible to demonstrate elements resembling consciousness in lower forms of life, such as birds or even ants.

But the further we go from humans, the less do these things relate to self-consciousness. What we are dealing with here are sentient life-forms, not consciousness. Therefore, to equate human consciousness with that of other animals is not possible.

These facts are well-known to anyone with the least interest in modern science and only an ignorant person or somebody who desires at all costs to ignore the facts and defend religious prejudice and superstition can deny them.

Seen in its proper context, there is nothing mystical about the human mind. Nevertheless, confusion has been introduced into the question by philosophers, who, in some cases quite deliberately, distort, misinterpret, and ignore the facts in their desire to peddle religious and mystical ideas.


The origin of this confusion in epistemology is to be found in the 17th century, when humanity was struggling to free itself from the religious obscurantism of the Middle Ages. An important step forward in the struggle was the development of empiricism in England.

In its early days empiricism played a most progressive and revolutionary role when it was directed against the Church and proclaimed the freedom of science and the superiority of observation and experiment over dogma. The early empiricists (Bacon, Locke and Hobbes) were materialists. As noted, their battle cry was “Nihil est in intellectu quod non sit prius in sensu”. (“Nothing is in the mind that was not first in the senses”.)

Their insistence upon sensory perception as the basis of all knowledge represented in its day a gigantic leap forward with regard to the empty speculation of the medieval Schoolmen. It paved the way for the rapid expansion of science, based upon empirical investigation, observation, and experiment.

Yet despite its tremendously revolutionary character, this early form of materialism was one-sided, limited, and therefore incomplete.

The assertion that there is nothing in the intellect which is not derived from the senses contains the germ of a profoundly correct idea. This is materialism. But the one-sidedness of empiricism leaves the door open to subjective idealism, which denies the existence of a material reality independent of the observer.

Presented in such a confused way, this idea had the most harmful consequences on the future development of philosophy. The great advances made by the early English materialists Hobbes and Locke were succeeded by the superficial epigone, David Hume, who later exercised a negative influence on the philosophy of Kant. In Bishop George Berkeley, this form of subjective idealism found its most consistent advocate.

This one-sided empiricism, that is to say, subjective idealism, has repeatedly made its influence felt on both modern bourgeois philosophy and science in a variety of different disguises. One of the most pernicious of these was so-called logical positivism. Under the influence of these ideas, the Austrian scientist Ernst Mach, whom Lenin deals with thoroughly in the present book, denied the existence of atoms, since they could neither be seen, felt, nor heard.


The arguments of subjective idealism at first sight may seem to possess an unanswerable logic. And indeed, if one accepts the initial premise, it is virtually impossible to answer. But one cannot accept such a premise without falling into the most absurd contradictions, as Bishop Berkeley himself soon discovered.

In reality, they are based on an intellectual swindle, the philosophical equivalent of the conjurer’s sleight of hand. The argument sets out from the following premise: “I know the world through my senses.” This statement is true and undeniable, as far as it goes. I can only know the world through my senses. But, as we have pointed out, we must add to this another statement: the world exists independently of my senses, or else we fall into the most grotesque contradictions and absurdities.

The whole of science is based precisely on the fact that:

a) the world exists outside of ourselves, and

b) in principle, we can understand it.

The proof of these assertions, if proof were required, consists in over 2,000 years of the advance of science, that is, of the steady advance of knowledge over ignorance.

The very word science comes from the Latin word “to know”, whereas the word ignorance is merely the Latin word for not-knowing. There are, of course, many things we do not know about the universe. But the whole history of science proves that what we do not know today we will know tomorrow. It is this constant search after truth that is the motor force for all progress in the field of thought and ideas.

As Lenin says:

…In the theory of knowledge, as in every other branch of science, we must think dialectically, that is, we must not regard our knowledge as ready-made and unalterable, but must determine how knowledge emerges from ignorance, how incomplete, inexact knowledge becomes more complete and more exact. (V. I. Lenin, Materialism and Empirio-criticism, p. 78.)


The re-emergence of long-dead ideas in different disguises reflects, on the one hand, the crisis of capitalist ideology. But on the other hand, it also reflects the philosophical vacuum that has been caused by the fact that Marxism was thrown back for a whole historical period following World War Two.

In 1909 Lenin’s book comprehensively demolished the subjective idealism of Mach and Avenarius. But subjective idealism itself is very much alive and well to this day. Ejected from the front door with a well-aimed kick in the pants, it merely crept round the back and sneaked in, unobserved, through a side window.

Ernst Mach 01 Image public domain
In 1909 Lenin’s book comprehensively demolished the
subjective idealism of Mach and Avenarius/Image: public domain

This subjective idealism was carried over into 20th century philosophy by the school represented by Ernst Mach and later the Vienna Circle (O. Neurath, Carnap, Schlick, Frank, and others) and logical positivism. In Britain, it was advocated by Professor A. J. Ayer, whose book Language, Truth and Logic was influential in the universities in the 1960s.

The basic thesis of Ayer’s book is that the only certain knowledge we can have is what he calls “sense contents”. In the early chapters of his book, this thesis is developed and repeated in different ways, giving the impression of an absolutely irresistible chain of logic. But the entire construction breaks down the moment he tries to explain what these sense contents actually consist of.

We can pose the question very simply, such that even a university professor can understand it: Can there be sense contents without eyes, ears, and a material brain? Can there be a material brain without a central nervous system and material body? And can there be a material body without the existence of a physical environment to provide it with the means of sustenance necessary for its existence?

Needless to say, none of these questions are answered, or even posed. As usual, the author assumes what has to be proved, and then concludes that he has proved it! For all its ‘clever’ and sophisticated appearance, this is a mode of thinking that is childish in the most literal sense of the word, as when a baby cries when its mother leaves the room because for it, she has ceased to exist.

These false and pernicious ideas represent the outlook of the petty-bourgeois intelligentsia, for whom everything starts and ends with ‘me’. ‘My business, my career, my individuality, my feelings, my oppression, my experience, my struggle against the unfair world, which does not understand me’ and so on and so forth. ‘If the world does not conform to me, something is wrong with the world.’

This summarises the world outlook of the petty-bourgeois intelligentsia, and determines its entire psychology. It is therefore hardly surprising that subjective idealism is its natural philosophical habitat. It holds the same fascination for the petty-bourgeois ‘thinker’ as a pot of honey does for a fly.

Now, even from the point of view of utility, one would have to say that this theory is absolutely useless. It cannot advance our knowledge a single millimetre. What difference does it make to a chemist in his laboratory to deny that the chemicals in his test tube possess objective being, or to describe them as merely a collection of sense-contents?

At the end of the day, he must still carry out his experiments in order to try to determine what the reality of these ‘unreal’ objects consists of. And after Professor Ayer finished spending all day denying the objectivity of matter, he presumably did not refuse to eat his dinner on the grounds that it did not really exist.

No doubt our logical positivist friends will reject these arguments as ‘naïve realism’, by which they mean materialism. This is a word they use as a term of abuse, which is intended to ward off any conceivable criticism. For our part, we prefer to use the same unsophisticated language that Lenin used when he referred to the subjective idealists merely as blockheads. This is an adequate characterisation of people who attempt to put forward ridiculous notions as serious arguments.

In Materialism and Empirio-criticism Lenin shows that subjective idealism inevitably leads to solipsism. Most logical positivists attempt to shrug off the allegation of solipsism, to deny it indignantly, to confuse the issue with all manner of complicated and abstruse jargon or simply to dismiss it as a joke.

But it yet remains for them to answer it.

The British philosopher Bertrand Russell once met a lady at a party who informed him that she was a solipsist, and wondered why there were not more of them. This amusing anecdote strikingly reveals the internal contradictions of subjective idealism. However, Russell’s joke cannot dispose of the philosophical problem of knowledge. This must be answered philosophically, that is, theoretically. Marx did this in the ‘Theses on Feuerbach’, and Lenin even more comprehensively in Materialism and Empirio-criticism.

For decades the advocates of logical positivism arrogantly presented their ideas as ‘the philosophy of science’. There is a deep irony here, since they also accused dialectical materialism (without the slightest foundation) of aspiring to the role of the ‘Queen of the Sciences’.

With the natural advance of science, open support for subjective idealism, just like religion before it, becomes increasingly untenable. Yet paradoxically, the ideas (or rather, the prejudices) of subjective idealism still exert a powerful influence on the minds of some scientists who were subjected to the half-baked nonsense of logical positivism in their student days and never recovered from the experience.


In Ludwig Feuerbach, Engels states that the great basic question of all philosophy, especially of modern philosophy, is that concerning the relation of “thinking and being”, of “spirit and nature”. He then proceeds to deal with one of the most important questions in philosophy: the theory of knowledge.

He asks:

…In what relation do our thoughts about the world surrounding us stand to this world itself? Is our thinking capable of the cognition of the real world? Are we able in our ideas and notions of the real world to produce a correct reflection of reality? (F. Engels, Ludwig Feuerbach and the End of Classical German Philosophy, Marx and Engels Collected Works (Henceforth referred to as MECW), Vol. 26, Lawrence and Wishart, p. 367.)

“The overwhelming majority of philosophers give an affirmative answer to this question”, says Engels, including here not only all materialists, but also the most consistent idealists like Hegel, who considered the real world to be the realisation of a mystical ‘absolute idea.’ But he adds:

In addition there is yet another set of philosophers – those who dispute the possibility of any cognition, or at least of an exhaustive cognition, of the world. Among them, of the more recent ones, we find Hume and Kant, and they have played a very important role in philosophical development. (Ibid., p. 367.)

Thus, we see that there are really three trends in philosophy: two consistent, or monist tendencies – materialism and idealism – and one inconsistent tendency that vacillates between empirical materialism and subjective idealism. The latter school of thought was given its fullest expression in the philosophy of Immanuel Kant. Hume and Kant, the true ancestors of logical positivism, both tended to fence off ‘the appearance’ from that which appears, the perception from that which is perceived, the “thing-for-us” from the “thing-in-itself”.

Kant granted the existence of the material world, but tried to establish a boundary beyond the world of appearance, the “thing-in-itself”, which he declared to be “unknowable”, something fundamentally different from the appearance, belonging to the “beyond” (Jenseits), inaccessible to knowledge, but revealed to faith.

Here sense perception appears as a third term separating the external physical world from the perceiving subject (the Ego). The senses appear as a barrier to real knowledge, rather than a bridge to understanding and thus dominating the real, physical world.

The Kantian trick was to confuse the unknowable with the unknown. In reality, the “thing-in-itself” gradually becomes a “thing-for-us” through the constant progress of human consciousness, science, industry, and technology. Through this progress, what was unknown yesterday is known to us today or will be known tomorrow.

For Marxists human ideas and concepts are in the final analysis nothing but reflections of the material world. The truth of these reflections is tested, and if necessary, the ideas adjusted, on the basis of human activity.


Early, mechanical materialism was unable to solve this problem and arrive at a scientific understanding of the real relationship between subject and object. This is what Marx deals with in his Theses on Feuerbach. The early materialism was limited by the level achieved by the science of the day, which was very rigid and mechanical in nature (Engels referred to it as the “metaphysical outlook”, although we use the word metaphysics differently today).

Mechanics sees the relation between subject and object in a simplistic, static and one-sided way: pushing, pulling, levers, pulleys etc. All motion is imparted from without. Newton’s mechanical universe required the Almighty to give it a push to set it in motion, but after that it worked perfectly, like clockwork. The relationship was passive and one-sided.

In this clockwork universe, there is little or no room for subjective activity and creative initiative. Every action is predetermined by Nature’s Eternal Laws.

By contrast, the idealists exaggerated the role of the subject, seeing it as all-important. They even derived the existence of the object from the subject. The conception of the activity of the subject was contained and developed by the objective idealist, Hegel. That is what Marx meant when he said that the subjective element was developed by the idealists, not the materialists. It was the bringing together of the two elements, the concept of activity of the subject of the idealists and the notion of the objectivity of the material world, which was the key to solving the problem.

The arguments of subjective idealism and the subject-object problem are easily dealt with once we adopt the standpoint of practice and approach the theory of knowledge from a concrete historical point of view, and not from the standpoint of empty and static abstraction. This was dealt with by Marx in the second of his Theses on Feuerbach:

The question whether objective truth can be attributed to human thinking is not a question of theory but is a practical question. Man must prove the truth, i.e., the reality and power, the this-worldliness of his thinking in practice. The dispute over the reality or non-reality of thinking which is isolated from practice is a purely scholastic question. (K. Marx, ‘Theses On Feuerbach’, MECW, Vol. 5, p. 367.)

Ultimately, the truth of materialism is provided by the history of science itself. Humankind does not merely contemplate nature but actively transforms it, and this ceaseless productive activity is what demonstrates the correctness or otherwise of ideas, as Engels explains:

The most telling refutation of this as of all other philosophical quirks is practice, namely, experimentation and industry. If we are able to prove the correctness of our conception of a natural phenomenon by bringing it about ourselves, producing it out of its conditions and making it serve our own purposes into the bargain, then the ungraspable Kantian ‘thing-in-itself’ is finished. The chemical substances produced in the bodies of plants and animals remained just such ‘things-in-themselves’ until organic chemistry began to produce them one after another, whereupon the ‘thing-in-itself’ became a ‘thing for us’… (F. Engels, Ludwig Feuerbach and the End of Classical German Philosophy, MECW, Vol. 26, pp. 367-368.)


In the period of its historical ascent, the bourgeoisie played a most progressive role, not only in developing the productive forces, and thereby mightily expanding humanity’s power over nature, but also in pushing back the frontiers of science, knowledge, and culture.

Luther, Michelangelo, Leonardo, Dührer, Bacon, Kepler, Galileo, and a host of other pathfinders of civilisation shine like a galaxy, illuminating the broad highway of human cultural and scientific advance opened by the Reformation and Renaissance.

In its youth the bourgeoisie was capable of producing great thinkers: Locke, Hobbes, Kant, Hegel, Adam Smith, and Ricardo. In the period of its decline, it is only capable of producing flea-crackers.

Foucault Image public domain
The degeneration of bourgeois philosophy is a reflection of the dead-end of the
capitalist system itself / Image: public domain

The latest major wave of such ideas came in the 70s, 80s, and 90s as a reaction to the defeats of a series of revolutions worldwide – defeats which were compounded by the collapse of the Soviet Union. This led to the growth of the school of postmodernism which covered postmodernist philosophy, poststructuralism, postcolonialism, queer theory, and a whole host of so-called theories based on identity politics.

But whereas Mach and Avenarius, as Lenin brilliantly showed, were bad copies of Berkeley, Kant, and Hume, today’s postmodernist geniuses are bad copies of bad copies. Desperate to appear original and trying hard to hide their incompetence they stuff their works with incomprehensible, convoluted, and intentionally ambiguous language.

They say there is nothing new under the sun. That statement is proven to be true by the entire history of bourgeois philosophy in our times. Every single school of philosophy for the last 150 years at least is merely a regurgitation, in one way or another, of the irrational ideas of subjective idealism – the crudest, most absurd, and pointless varieties of idealism.

The latest postmodernist craze is just another one of these variants. It has served to confuse and disorient a whole generation of philosophy students in the universities, who imagine that they have discovered something entirely new and novel, when in reality they merely repeat the absurdities of earlier philosophies, which were already comprehensively demolished by Lenin as early as 1908. Here we have the most striking proof of the correctness of Marx’s celebrated dictum: “social being determines consciousness”.

The degeneration of bourgeois philosophy is a reflection of the dead-end of the capitalist system itself. A system which has become irrational must lean on irrational ideas. In attempting to maintain itself, the bourgeoisie has turned against its own revolutionary past. Turning against the best traditions of the enlightenment, capitalism is clinging ever harder to the modern-day descendants of feudal mysticism and scholasticism.

A man on the edge of a precipice is not capable of rational thought. In a vague way, the ideologues of the bourgeoisie sense that the system they defend is reaching its end. The spread of irrational tendencies, mysticism, and religious fanaticism reflects the same thing.

Nowadays, the subjective idealists are reduced to fighting a desperate rear-guard action, which amounts to the total dissolution of philosophy, reducing it entirely to semantics (the study of the meaning of words).

The endless arguments about meaning and semantics and the minutiae of meanings resembles nothing so much as the interminable debates of the medieval Schoolmen on such fascinating subjects as whether angels had sex and how many of them could dance on the head of a pin. The problem is that in their obsession with form, they forgot the content altogether. As long as the formal rules were obeyed, the content could be as absurd as one liked.

Marx once observed: “Philosophy and the study of the actual world have the same relation to one another as onanism and sexual love.” (K. Marx and F. Engels, The German Ideology, MECW, Vol. 5, p. 236.) Modern bourgeois philosophy prefers the former to the latter. In its obsession with combatting Marxism (and materialism in general), it has dragged philosophy back to the worst period of its old, outworn, and sterile past.

The fact that all this fussing and fiddling and playing with words could be given the name of philosophy at all is a proof of how far modern bourgeois thought has declined. Hegel wrote in The Phenomenology of Mind: “By the little with which the human spirit is satisfied, we can judge the extent of its loss.” That would be a fitting epitaph for all of bourgeois philosophy after Hegel and Marx.

In the present period, the honour of fighting against the stream, of combatting mystical and irrational thought, falls to the revolutionary vanguard of the working class, the Marxists. To cite once more the words of Joseph Dietzgen: “Philosophy is not a science, but a safeguard against social democracy.” (In those days, the Marxists called themselves social democrats.)

And he added: “Then it is no wonder that social democrats have their own philosophy.” That philosophy – the philosophy of Marxism – is called dialectical materialism. It remains one of the most important weapons in our revolutionary arsenal.

And anyone who wishes to understand how to use that weapon correctly should consider it a duty not just to read, but to make a careful study of one of the most fundamental texts in all the rich arsenal of Marxist thought, Materialism and Empirio-criticism.

London, 16 December 2020

[1] The word fideism comes from fides, the Latin word for faith, and it is a theory that maintains that faith is independent of reason, and faith is superior at arriving at particular truths.