A formidable final essay. Transcribed in English for the first time, Paul Lafargue’s last major work, The Problem of Knowledge, was originally published in the Revue des Idées on December 15, 1910.

‘The Problem of Knowledge’ (1910) by Paul Lafargue from New Review. Vol. 1 Nos. 19 & 20. August & September, 1913.

(Translated by Richard Perin)

I.

Many philosophers doubt the positive character of our knowledge concerning the external world, because, as Berkeley says, the impressions which we receive through our senses are doubtful, and because our mind, an incorporeal essence, can perceive no corporeal objects. Our knowledge is subjective and we know only the idea which we form of an object; its characteristics, its size, the causes which bring it into existence, its constitution, its relations to the world about it and its variations in space and time are but creations of our reason, mere expressions of our conceptual power. In the same way, according to Kant, causation, space and time are necessary and universal conceptions of our mind. Hence the world about us, in the form in which we see it, is a creation of our own power of imagination. According to Hume, the substance of things is unknown to us, according to Kant the “thing in itself.” The knowledge of things is for us an eternal impossibility.

Huet,¹ the learned bishop of Avranches, ridiculed Descartes, “the so-called inventor of truth”; for at first he was wise enough to doubt everything, but in his very next step he deviated from the right road and affirmed everything, although man can affirm nothing, since he has no certain knowledge of anything, except perhaps the truths which God himself has revealed to us and which are taught by Holy Church. Pyrrho’s sceptism as a theological argument! Charron, the fiery preacher of the Catholic League in the sixteenth century, applies it in the same way; he considers it “a good school” for religion: “In order to plant Christianity in the hearts of a godless and unbelieving people and to cause it to flourish, it is of great advantage to begin to teach it by making the people believe that the world is full of and corrupted by fantastic notions, which we have constructed in our own brains; God indeed created men that they might know the truth, but we cannot know it of ourselves nor through any human agency, but God himself, in whom it lives and who has implanted in man the desire for it, must reveal it to us, as in reality he has done.”²

With Pascal, however, certainty loses its last and only prop, the revelation of truth by God: “Pyrrho’s chief strength,” he says, “consists in this, that we have no certain knowledge of the truth beyond religion and revelation…Since, therefore, excluding religion, there is absolutely no certainty whether man was created by a benign God, an evil demon or an accident, it is doubtful whether these principles are given to us as true, as false, or as uncertain, depending upon our conception of our origin.

“What is man to do in this situation? Shall he doubt everything? Shall he doubt when he is stabbed or burned? Shall he doubt that he doubts? Shall he doubt his own existence? We cannot go as far as that; and I hold as indisputable that there has never been a really absolute sceptic (pyrrhonien).” (Pensées, VIII, §1.)

Many philosophers have combatted the notion that knowledge is impossible. First of all the idealist Hegel: “When we know all the properties of a thing we know the thing in itself; all that remains to prove is that said thing exists outside ourselves, and when our senses furnish us with this proof, then we have completely and fully comprehended the object, Kant’s unknowable ‘thing in itself.’

The Socialist Engels refutes the idea from the standpoint of a political economist: “In Kant’s time our knowledge of nature was so defective that he could consider himself justified in assuming the existence of a mysterious ‘thing in itself’ behind the little which we knew of anything. But thanks to the tremendous advance in science, we have comprehended these incomprehensible things one after another, we have analyzed them and most important of all, have produced them ourselves; we cannot consider and proclaim as unknowable that which we can produce.” (Introduction to “Socialism, Utopian and Scientific.”) An ordinary mortal does not allow himself to become agitated over such doubts, although he knows how often his senses deceive him; nor do the philosophers, who rack their brains over the certainty of knowledge, do so when they step down from the heights of pure reason and metaphysical speculation into the world of reality. Scientists ignore this problem when they are investigating natural phenomena. Nevertheless, since the revival of the Kantian philosophy there are scientific men who become excited about it. More angered than perplexed by these doubts, they consign them to perdition and declare like the physicist Le Bon: “Science is not obliged to concern itself with things in themselves and to contrast them with appearances, that is to say, the phenomena revealed to us through our perceptions. Since the impressions derived from our senses are almost the same for all men constructed after the same plan, science can regard them as real, and can rear its structure upon them. To science it is quite immaterial whether the world which we perceive is real or not. It accepts the phenomena as they are and seeks to adapt itself to them…Our items of knowledge are adapted to us and only for that reason do they interest us.” Le Bon thus sets aside the Kantian doubt; but he does not combat it, on the contrary, he acknowledges it. The naturalist Le Dantec, on the contrary, attacks it and deals it a death blow: “The fact that we live and that the human race does not disappear suffices for us to assert that our knowledge of the outer world is not deceptive and that it applies to all the phenomena about us which serve to maintain our existence.”³

The doubt of the reliability of knowledge, which for more than two thousand years has occupied the thoughts of men and has acquired such great importance in philosophy, merits an investigation into its historical origin and causes and an endeavor to explain and refute it.

The problem of knowledge was taken up by the Sophists of ancient Greece with a logical boldness which the modern philosophers did not possess when the subject was broached anew. The items of knowledge which are transmitted to us through our senses appeared to them questionable and doubtful, and for the conception of Pure Reason they had not the slightest respect. They said: Our senses inform us but imperfectly; when a twig is dipped into water, it appears to be broken; on the horizon the moon appears much larger than in the zenith; a round tower appears flat from a distance; the trees along the two sides of a path appear to approach closer to each other the further we recede from them; a substance that is pleasant to the nose may be disagreeable to the taste; a painting that appears uneven to the eye is flat to the touch; when we roll a ball under the index finger and the middle finger crossed over it, we receive an impression of two balls; when we are upon a moving ship, the hills on the shore seem to be moving, and so on.

The senses not only deliver to us wrong impressions, but these impressions vary with different individuals and with the state of the same individual: a smell which is pleasant to many affects others disagreeably; honey seems sweet to one, bitter to another; Democritus maintained that it was neither sweet nor bitter, and Heraclitus that it had both properties; we may freeze when we go to a banquet, and perspire when we come away from it, while he who was not there does not notice this change at all, and so on.

Since things are known to us only through the impressions of our senses, we know only how they appear to us, but not how they are; why should we suppose, says Anesidemus,⁴ that our perceptions of the nature of things are more correct than those of the animals; animals with telescopic eyes must receive visual impressions different from ours. An object, upon contact, gives an entirely different impression when the body is covered with a hard shell from the impression given when the body is covered with scales or feathers. The difference in sensibilities is attested by facts: oil, which is useful to man, kills bees and wasps; hellebore, a deadly poison to man, makes quail and goats grow heavy and fat; sea water, absolutely necessary to the life of fish, is injurious to man if he is kept in it for a prolonged period, and so on.

“Since we know things only through our senses,” says Aristippus, a pupil of Socrates, “we cannot know whether they really possess the properties through which they act upon us; we have the sensations of sweetness, whiteness, warmth, but we do not know whether the things which cause these sensations are really sweet, white or warm.”

Protagoras, the ingenious Sophist, whose views, unfortunately, we know only from one or two mutilated quotations, and from what Plato tells of him in his dialogues (he was obliged to doctor and weaken them in order to be able to refute them, though, to be sure, he does not always succeed), says: “As the eye is blind so long as no colored object is present to excite it, so the object is colorless so long as there is no eye to recognize it; there is no object in and for itself, and no object becomes what it is or will be except to the individual who perceives it, and he naturally perceives it variously, according to the condition in which he may be. Things are to everybody only that which he sees in them according to his nature, consequently man is the measure of all things, of the existent as it is, of the non-existent as it is not.” This famous proposition of Protagoras is the entire basis of subjective philosophy, the philosophy of the bourgeoisie, the individualistic class par excellence, the members of which measure all things in accordance with their interests and inclinations.

The Sophist doubted his own perceptions as little as Descartes doubted his own thoughts; he was certain that he was alive, saw light and enjoyed the odor of the rose; he did not deny that to him the rose seemed fragrant and the snow white, but he did not know whether the rose really was fragrant and whether the snow really was white; nor did he know whether rose and snow awakened exactly the same sensations in others; certainly not, for their nature was different from his; hence how can we know that things appear the same to all men? We can indeed know something of our own impressions, he asserts, but we know nothing of the things themselves, and still less do we know the impressions of other men. The most varied sensations are expressed by the same word; when two men assert that they have the same sensation, neither can state with certainty that the perception of the other is the same as his own, for he can only feel according to his own subjectivity and not according to that of the other man. We cannot know things, nor communicate to another the impressions which they produce in us; we exchange words, but not sensations. Consequently there is no universally valid knowledge, since it could rest only upon perceptions; there are only opinions, asserts Protagoras, but there is no correct universally valid opinion.

The Sophists taught that we should not accept current opinions without examination, not even those inherited from our fathers, but that everybody must form his own opinions for himself, must accept as true only that which seems to him to be true, and attribute value only to that which corresponds to his personal conviction and brings him some advantage. Thus they laid the foundation for a new philosophy, in which, as Hegel remarks, the principle of subjectivity was to predominate. They prepared the ground for this philosophy in public courses of instruction, by teaching only that which served to make men happy, and they praised highly the renunciation of all investigations into the nature of things, to which the old natural philosophy had devoted itself; for these investigations are absolutely sterile. The Catholic Church also hurled its thunderbolt against natural science, that invention of Satan. The Sophists and the Church formerly represented the spirit of the bourgeoisie, who, bent above all things upon profits, refused to support such a study until it became convinced that a knowledge of the forces of nature and their utilization in industry formed a source of inexhaustible wealth.

Socrates, according to Grote the most eminent of Sophists, attached greater value than any other man to the formulation of the subjective philosophy and its final separation from all science; as the starting point for his teachings he took, not the knowledge of things, but the knowledge of himself, of his ego. In the Phaedo, Plato makes him interpret the world through man, while the old philosophy, which, in content and tendency, was a natural philosophy, sought to explain man through the world.

He demanded that the sciences be immediately useful in practical life; of geometry, that which was necessary to surveying, of astronomy, merely that which was necessary “in order to know the hours of night, the days of the month and the seasons of the year.” Xenophon reports that he, “far from seeking the causes of the heavenly phenomena, pointed to the foolishness of the people who busied themselves with such contemplations…Whoever learns a trade,” he said, “hopes to exercise it later for his own and others’ benefit; but those who seek to penetrate into the secrets of the gods (that is to say, the secrets of nature), do they believe that they will ever be able to control the winds, the rain, the seasons according to their wishes or according to their needs, even when they shall have learned correctly the causes of all existing things? Or do they content themselves with a mere knowledge of the facts, without flattering themselves with such consciousness of power?” (Memorabilia, Book I.)

Socrates believed that he was wasting his time if he occupied himself with the properties of things; he recommended that things (pragmata) be abandoned for ideas (logoi); the real (onta), for the truth of the real (aletheia ton onton). This truth was the idea which men formed of things: the knowledge of the concept of a thing made superfluous any investigation into its nature. A knowledge of the idea “horse,” Plato maintained, teaches us the nature of the horse. According to him, ideas contain the reality; the latter receives its form not from matter but from the idea, it makes everything into that which it is, hence the idea represents the real embodiment of the thing.

But not all Sophists shared this high opinion of the conception of Pure Reason. They made all kinds of objections, for instance: we can only express that which we feel in a particular state, but we cannot assert anything positive of that which lies outside of ourselves, and we can assert no general truth, because the senses intervene between the outer world and the reason, which is, so to say, imprisoned and cannot escape from itself. They subject the ideas of motion and of space, the definitions of geometry and the arithmetical operations to an exact and painstaking criticism.5

Socrates abandoned science for ethics, the only study worthy of a free man. In fact, the Sophists busied themselves incessantly and chiefly with morals, customs, usages, justice and legality, which they subjected again and again to merciless criticism.

Gorgias boasted of his discovery that appearance was more important than truth, and Pyrrho declared that appearance was the master wherever it showed itself; that is the theory of appearance which the Sophists made the cornerstone of their ethics. Since to each man things are what they appear to him to be according to the impressions of his senses, therefore truth is merely an individual opinion; each should consider as true that which appears true to him, and as just and right that which appears to him to be just and right; for man is the measure of things in the physical as well as in the moral world. The boldest among them opposed nature to society, natural right to law, the external world (physics) to the mind (nous), and concluded therefrom that each must follow his own inclinations and interests; and whenever law and custom run counter to the latter, they infringe the natural right of the individual and place upon him a compulsion to which he need not submit. He may overstep it without hesitation if he can do so with impunity. No one should control himself according to any universally valid morality, but he should satisfy the inclinations and interests of his ego. The ego becomes the starting point of morality. The fundamental principle of the new doctrine was: “Do unto others as you would that they do unto you.” Thus Hesychius reports, and the Sophist Isocrates interpreted him: “Do unto others nothing that you yourself would not suffer from them.

“Conduct yourself toward others as you would that I should conduct myself toward you.” Christianity has accepted this principle and adopted it in the following form: “Do unto no man what you would not that others do unto you. Love thy neighbor as thyself.”

The Stoics, who inscribed upon their flag “Return to nature!”, although they rejected the simple natural philosophy, taught that in order to be free in every respect the wise man should accept no office nor any obligation to anyone; he should not take upon himself the burden of educating children, nor should he place his neck under the marriage yoke since there are so many other means of satisfying sexual needs. The Cynics satisfied them in public, in order to return completely to nature. Zeno, and also Plato, preached the community of women.

The Sophists attacked the social institutions. Lykophron declared that the superiority of the nobility was based upon a fanciful notion; Alcidamas said that the contrast between free men and slaves was foreign to nature; still others said that slavery was unnatural–city, state and nation, they taught, were too restricted for those whose home was the universe. The wise man is a cosmopolitan, he cannot belong to a city or a state, because he must not relinquish his liberty at any price, and because the road to the nether regions is equally distant from all places. It is ridiculous to sacrifice oneself for his country, the wise man, whose home is the world, will never sacrifice his life and his wisdom to please a few fools.⁶

Socrates, like Pyrrho, had not the courage to drive his doubts to their extreme logical conclusion; but long before Bentham he made the good dependent upon the useful. He advised men to be virtuous on account of the advantages which virtue brings; for instance, we should not commit adultery because of the dangers to which we thereby expose ourselves; we should participate in public life because the welfare of the community is also useful to the individual; we should cherish friendship, which found its idealized expression in the platonic pederasty, on account of the services which we may expect of it, and so on But in contrast to the other Sophists, Socrates identified legality with the conception of justice to such an extent that he refused to escape from a sentence which he considered unjust, merely in order not to violate the law. Like Pyrrho he made it a rule to hold fast to sound common sense and to do the same as others; and in order to avoid giving offense, he sacrificed to the gods, whose existence was to the Sophists as much a matter of doubt as the knowledge of things.

Hence the doubt of the Sophists as to the reliability of our knowledge and their contempt for all science led them to the acceptance of sound common sense as the guide of the wise and as the universal guaranty of that to which human knowledge may attain with certainty. To be sure, their starting point had been the opposition, in conjunction with Heraclitus, to the ideas then prevalent, which were the relics of an outworn social system.

The first Sophists originated in the commercial cities of Ionia and Greater Greece, where since the seventh century B.C. commerce and industry had undermined the communistic organization of the gens and the patriarchal family by displacing the community of goods with private property and forming a new class, the bourgeoisie.

For the numerous households that lived under the absolute authority of the father, who personified the ancestors, the patriarchal family was a kind of Providence: it cared for all bodily and spiritual needs. The crops of its fields and the labor of its slaves maintained its members; reverence for its ancestors, its history, its legends and traditions, and its rules of life, which were accepted without criticism and had unconditional validity, formed their spiritual and moral atmosphere.

The class of patriarchal aristocrats sank in proportion as the wealth and power of the merchants and tradespeople rose. The nobility, for whom war was the only means of acquiring wealth, had nothing but hate and contempt for these upstarts of commerce and industry. Theognis, an aristocratic poet, even wished to “drink their black blood.” But these despised individuals dared to contest with them the rule of the cities, to take away their estates by usury, to join with degraded nobles, artisans and slaves in order to rob them of power, to banish them and to expropriate their wealth. For centuries bloody civil wars raged in the cities of antiquity.

The individualistic society which the new class built upon the ruins of the patriarchal family community, had no providence at its disposal such as was represented by the patriarchal family, and to compensate for this lack it created for itself the providence of God. Instead of, as formerly, hoping for prosperity from the good fortune of the entire family, the member of the new society now made his prosperity dependent upon the success of his individual enterprises; freed from the despotism of the patriarch and left to his own devices, he was now obliged to provide for his own bodily and intellectual needs. The Sophists undertook his education, which in olden times had been the task of the family: they founded the first schools in which a charge for tuition was made, and in which they taught everything that a man should know in order to fight his way in the struggle for existence, being restrained neither by the morality nor the outworn customs of the patriarchate.

Instead of sacrificing his individuality to the gens or patriarchal family, man now placed his ego in the foreground of society; instead of taking the community into consideration in all things, he now took thought only of his own person, his ego, he was “the measure of all things,” according to the profound saying of Protagoras. In the new social conditions was rooted the principle of subjectivity, from which the Sophists derived the subjective philosophy, which became the philosophy of the bourgeoisie.

Aristophanes and Anytos accused Socrates of despising the gods and the ancestral customs, of corrupting morals and demoralizing the young. Similar accusations were also made against the other Sophists, but their teachings were adapted to the intellectual and moral needs of their time and were the philosophical expression of that time. Says Plato: “The people is the great Sophist, whose ideas and inclinations must not be opposed.” The people were in the throes of a complete moral dissolution: Thucydides states that they permitted themselves all kinds of excesses, dishonesty was the order of the day, and the most solemn oaths could not be trusted. The crowd applauded the most self-seeking and shameless utterances of its favorite orators, such as the following: Each pursues his own interests as well as he can, without ever allowing himself to be restrained by consideration for the right; the right of the stronger is a natural law; in the end everybody measures right and honor by the standard of his own advantage and pleasure, and so on. The doubt of knowledge and cynical rejection of personal and general concepts of morality are the intellectual reflections of the transformation in social conditions which had been brought about by economic and political events and which completely remodeled ancient society.

Doubt, which was born at the same time as the bourgeoisie, established itself in its philosophy. Descartes believed that he had dislodged it with his famous axiom: “I think, therefore I am” (Cogito, ergo sum); he might just as well have said: “I feel, therefore I am.” He shot beside the mark. The Sophists never doubted their thoughts or feelings, but the certainty of the knowledge which these were able to furnish them. This doubt continues to flourish undisturbed in the minds of the philosophers.

At various times, during epochs of transition, the dissolute morality of the Sophists made its appearance in the history of the bourgeoisie, but at no other time has it been proclaimed with such cynicism.

II.

The sophistic criticism of the false and variable impressions of the senses has not been refuted and cannot be refuted; every day it is confirmed by countless striking proofs of the unreliability of our senses. It is approved in the popular saying, “There is no disputing about tastes and colors.”

Hardly two years ago, Blondot, the famous physicist of Nancy, discovered the N-rays, the presence of which could be ascertained by a bright spot upon a phosphorescent screen; numbers of European and American scientists, as expert experimenters as himself, also saw this bright spot; and yet they finally had to admit that these rays were an optical illusion of the observer. Every man sees the sun shining in brilliant light; those skilled in optics maintain that if an aeronaut could pass beyond the earth’s atmosphere, the sun would appear black to him. In order to show that the same object produces different impressions upon different individuals, a professor of psychology had a clown enter the lecture-room suddenly, turn three or four somersaults and as suddenly withdraw. The professor asked his audience to state what they had just seen, without conferring with each other; no two statements agreed in respect. to the movements and the clothing of the clown. The legal testimony of eye and ear witnesses is contradictory unless it has been previously agreed upon; thus in the Steinheil trial ten witnesses, among them six policemen, accustomed to making investigations at the scenes of crimes, gave varying testimony in regard to the position of Steinheil’s body; his servant and a neighbor saw it stretched out upon the floor; four policemen found him kneeling and leaning against the door, the fifth saw him with his back turned toward the wall near the washstand, etc. When an historian has but a single piece of evidence, he will make positive statements in regard to an event; but if several documents are in existence, he will be uncertain as to details and often as to the whole. Where is the historian who could untangle the Dreyfus case, which is obscured by so many different kinds of statements? History is not an exact science.

The conceptions of Pure Reason, which to Plato appeared incontrovertibly true, are necessarily erroneous, since they are sense-perceptions transmitted through the brain, when the senses transmit only imperfect impressions to the latter. Pure Reason, to which Kant ascribed all certainty, appears so uncertain that we must examine its conclusions in the light of experience, which, in the judgment of Poincaré, the mathematician, is the only source of truth. Common sense corrects the judgment of Pure Reason. The senses deceive the mind, which in its turn deceives the senses. Therefore Charron wrote triumphantly: “See, how marvellously far man can go with his insight and certainty when the inner and outer world are equally filled with errors and defects, when reason and the senses, the chief tools of science, are mutually misleading.”

Public opinion and common sense, which Socrates and Pyrrho in ancient times, Thomas Reid and Royer Collard in modern times, took as their guide, are unreliable also. Both consist primarily of perceptions, which may be deceptive; thus because our vision deceives us as to the size and the path of the sun, public opinion and common sense declared that the sun revolves about the earth, that the earth is the centre of the universe.

The Sophists maintained that different impressions are received by each individual, hence we can create no objective science. And in reality a science founded only on sense impressions would have a limited validity, it would necessarily be purely subjective, and would vary not only with individuals, but also with the changes which age effects in the senses.

But since, as Le Dantec says, we are still living and our species has not become extinct, the latter must have possessed a more or less perfected and certain minimum of knowledge in order to adapt itself to the natural and social conditions to which it was subjected. This minimum of knowledge must have general validity, since the men of the most various races and countries established state and family institutions, forms of property and methods of production which resembled one another and which were evolved from one another. As the popular proverbs show, which in Vico’s opinion always contain the same kernel in different shells, common sense is essentially the same everywhere. But in order that such a similarity in social and economic evolution could occur among all the peoples of the earth, this minimum of knowledge must have increased to the extent to which man broadened his experiences.

This similarity also extends to the animals, and among them leads to the same consequences, for, as Charron says, “there is close relationship and affinity between man and the higher animals.” Apparently the supposition, shared also by the Sophists, is correct, that the pupilled eyes of certain vertebrates and the compound eyes of insects, as well as the eyes with arched cornea and strongly convex lens of the short-sighted, see the same objects differently from the eyes of the far-sighted, which are provided with flattened cornea and lens; but that does not prevent them from obtaining a similar knowledge of the outer world, which is exact to the extent that they know how to procure the means of existence, to protect and defend themselves and to rear their progeny. Since they are formed of the same substance, present the same cellular structure, and, in order to sustain and reproduce themselves, must undergo an unlimited number of experiences which are more or less alike, men and animals must have had the same sense impressions and attained to similar knowledge. Hence, for example, it is more than probable that the animals have mastered the first principles of mathematics; a donkey, says Diogenes, knows as well as a mathematician that a straight line is the shortest path to the manger or the water-trough; pigeons do not begin to set until the female has laid two eggs, as though they knew that 1+1=2; the sheep know the time of day without having learned the conception thereof from Pure Reason, they know as well as the shepherd does when the time has come to return to the stable; chickens have a certain idea of space and prove it by their reluctance to mount to a roost higher than that to which they are accustomed. This idea of space is not inborn with the animals, that is, it is not instinctive; we may, for instance, observe how puppies acquire it. Hence we must admit that in spite of the diversity of the impressions produced among men and animals by the same things, more or less similar ideas are formed by both, since both are made of the same substance. Hence if it is impossible to deny to men and animals a certain minimum of knowledge, we must, with Freycinet, acknowledge “the peculiar approximation (adéquation) of the outer world and the intelligence,” which Parmenides defined when he said: “The possible alone can be conceived, and the consequence of that is that our art of computation and its various combinations, in other words the language of mathematics, as the human intellect created it, is wonderfully adapted to express the processes of nature…Formulas that had been invented for theoretical speculations proved subsequently to be in exact conformity with natural phenomena, indeed they often express them best.” Who could have thought that the proposition: “Spherical surfaces are in direct ratio to the square of their radii” would ever serve as well for the decrease in gravity and in radiating forces; that the series of odd numbers would represent the distances covered by a freely falling body during the separate and successive moments of its fall; that the curves produced when we cut a sphere through planes which have different inclinations to its axis (a discovery made by Appolonius of Perga more than two thousand years ago) would serve Keppler as the basis of his astronomical system? To this Freycinet adds: “It is difficult to see merely a remarkable coincidence in these facts and to ascribe to accident alone so many concurrences. I see therein proof that the human mind and nature obey a definite plan, which in a marvellous fashion. enables the mind to understand nature.”⁷ Freycinet’s plan, which presupposed a God as creator, can be nothing other than the universal composition of matter in the universe, which is everywhere the same; hence animate and inanimate substances are composed of the same elements, and therefore man can understand the world. Berkeley says with justice: “The mind, as an immaterial being, cannot perceive material things,” but matter endowed with intelligence can perceive them.

This knowledge, even though a minimum, which we cannot deny to man, is not yet science, but merely a preliminary step toward science; if, in order to know the outer world, man had availed himself of his senses only, this knowledge would hardly have advanced further than that of the animals, whose senses are far more perfect, with the exception of the sense of touch, which has been extraordinarily developed by the use of the hand. Thus, for instance, geometry would not have come into being if man had not invented the rod to measure the length and breadth of fields, instead of estimating them with the eye. The rod used by primitive peoples to measure arable land, which every year was partitioned anew among the families of the gens or of the village, was of such great utility to them that it assumed a mystical character: the peasants of the Russian Mir (village community) called it the “Holy Rod” and kept it in the church; the Egyptians chose the ell, the unit of measure for the division of arable land, as the hieroglyphic symbol of truth and justice; everything measured by it was just and true.

A piece of wood, a rod, takes the place of one of the senses: from that time on the length and breadth of a field was no longer a mere perception of the eye, uncertain and variable according to the individual; that which it measures is true and just, and there is no further occasion for disputes as at the time when it was estimated by the eye.

We know the properties of things by the impressions which they make on us: it is through sense impressions that we first come in contact with the outer world, and during childhood they form our only means of knowing things. The savages use them almost exclusively, hence the superiority of their senses. But the properties of things exert an influence not only upon our senses, but also upon inanimate bodies. The weight of a thing makes itself perceptible upon the scale as well as in our hands; its hardness. its temperature, its luminosity, etc., affect inanimate bodies as well as our animate bodies; hence we may define the properties of a thing as its inherent power of exerting an influence upon animate and inanimate bodies.

The sensitiveness of inanimate bodies is even more delicate than that of animate bodies; thus the former are caused to vibrate by the Hertzian waves of wireless telegraphy, which we cannot notice at all; we would be unable to distinguish the degrees of hardness of the various kinds of steel if we merely used our senses and not the Brinell measuring apparatus in Keep’s drill. The result is that we can avail ourselves of the sensitiveness of inanimate bodies in order to learn the properties of things: a column of quicksilver, for instance, to measure the temperature, litmus paper to ascertain whether a liquid is acid or basic, and so on. Hence, Kant and the Neo-Kantians are guilty of a grave error when they assert that we know, and can know, the properties of things only through the impression of our senses.

Therefore it is no longer the uncertain and variable perceptions of men which form the basis of our knowledge, but the certain and invariable influence upon inanimate bodies; although formerly it was impossible to know the temperature of the air with exactness, as long as we were limited to the uncertain and variable impressions upon human senses, we have been able to ascertain it exactly since the sensitiveness of quicksilver indicated it to us. Two astronomers who observe the same star will make different drawings of it, while the photographic plate, the “retina of scientists” as Jansen calls it, presents an exact picture. Since photography has the advantage over the eye of eliminating all subjectivity and of preserving faithfully the imprints of the impressions acting upon it, it is replacing to an ever-increasing extent observations by the naked eye. Maneuvrier’s little apparatus, which is based on the fact that electrical resistance is proportional to the aqueous contents of a mixture, reveals to us far better than the tongue of the most experienced gourmand whether a wine is diluted or not. Analysis by freezing enables us to determine exactly, by the amount of ice formed, how much water has been added to milk, and to diagnose the state of health of an unseen milch cow, which would be impossible to the most skilled veterinary. Man has only learned the tone of his own voice since the invention of the phonograph, and even then he does not recognize it, for he hears it, as others hear it, without the resonance of his head.

The exact knowledge, universally valid because always the same, which we gained by the substitution of inanimate nature for our senses, enables the physician to diagnose disease by its aid, the psychologist to employ it in the study of the psychical properties of the ego. Socrates said: “Know thyself!” and modern man adds: “with the aid of inanimate matter.”

Wherever possible science is substituting inanimate things. for the senses of the scientists. In many sciences this substitution has been completed: the chemist employs none of his senses to learn the properties of the sulphuric acid or other bodies which he analyzes or combines; we could endow him with a new sense or deprive him of one of the old ones without altering his scientific knowledge, for this is not based upon the perceptions of the senses, which are subject to errors and variations, but upon the knowledge of matter through inanimate matter, which is subject to no errors and variations.

Industrial production, which at one time was in advance of science, must now follow limping after: as long as its control was dependent upon human senses it was unreliable; in spite of the most thorough training there was often no plausible explanation at all of false or poor manufacture. Reliability was not attained until we had recourse to every possible kind of recording apparatus, from the simplest (thermometer, manometer, etc.) to the most complicated (voltameter, amperemeter, pyrometer, calorimeter, etc.).

The substitution of the sensitiveness of matter for human impressions, which enables us to learn temperature by the degrees upon the column of quicksilver, tone by the number of acoustic vibrations per second, etc., transforms that which is quality for men into quantity with respect to matter. This transformation enables us to replace phenomena by numerical proportions, and alters the nature of our knowledge The qualitative knowledge of a thing is knowledge of it in respect to men; the quantitative knowledge of it is knowledge with respect to other things. The principle of subjectivity, the starting point of the subjective philosophy of the bourgeoisie, is replaced by the principle of objectivity.

Even when they do not mislead us, the senses only furnish us with an extremely limited knowledge of things, revealing to us only some of their properties; for instance, the eye does not perceive one-tenth of the solar spectrum; its receptive power is far below that of inanimate matter; where the eye of the astronomer is unable to penetrate the darkness in the empty space which Herschel described as a “coal-sack,” the photographic plate reveals new constellations and scattered cosmic matter; the more sensitive photographic plates become, the more extended does astronomic knowledge become, knowledge of even the most secret depths of the heavens.

The limits of the sensitiveness of matter are unknown to us; that of scientific instruments is restricted, and yet it becomes finer from day to day. The thermometer, which could hardly measure 100 degrees, left us in ignorance in regard to phenomena which the bolometer has made plain to us; this instrument, which is based upon the electrical resistance of metals under the influence of heat and which can indicate the millionth part of a degree, showed us that the solar spectrum is much more extensive than was supposed. Scientific knowledge does not advance in proportion to the perfection of our senses, but in proportion as the methods for utilizing the sensitiveness of inanimate matter become more general and as the apparatus of re- search and control become more numerous and more sensitive.

However, the knowledge of things will always be incomplete, on account of the lack of perfection of our senses, and of the instruments which replace them, and on account of the methods which we must employ in our investigations.

No object is entirely independent of the outer world; it is determined by the coincidence of an infinite number of conditions and accompanying circumstances; it never remains the same; influenced in an infinite variety of ways by its environment, it is in a state of constant change; in order to study it, we must regard it as entirely independent of its environment, as invariable, and must test its properties one after another. The abstract sciences have all struck out along the same road: it was possible to obtain the objects of their studies, the point, the line, the surface, numbers, only by separating them from their environment and depriving them of their physical properties, in order to transform them into imaginary entities, devoid of objective reality and only existent in the mind of him who conceives them.⁸ For this reason the theoretical deductions of mathematics, which do not depend upon the senses, are not subject to the errors of the senses, and since they are logically constructed they have universal validity, because they correspond to the universal laws of human reason; hence the geometries of Euclid, Lobatschefsky and Riemann, although they are mutually contradictory, are accepted as true by mathematicians, for their propositions form strictly logical systems.

The natural sciences, which substitute instruments for the senses, are as universally valid as the abstract sciences, since the scientist does not analyze his impressions; he studies the actions of things, not upon his senses, but upon other things; he records them and classifies them in order to deduce from them theoretical conclusions and possibilities of practical utilization; he examines the influences of things, not upon his senses, but upon other things. Knowledge was subjective as long as it was based upon the results of the perceptions of our senses, it became objective so soon as it was based on the facts furnished us by the objects. The incisive and incontrovertible criticism of the Greek philosophers, who undermined the foundations of subjective knowledge, cannot affect objective knowledge.

The Sophists, the pitiless destroyers of subjective knowledge, with an incomprehensible inconsistency took men, whose knowledge they denied, as the measure of all things, and abandoned the old objective natural philosophy, in order to found the subjective philosophy of the bourgeoisie. The men of science who created the objective knowledge of nature, thus returning to the philosophy of the ancients which was despised by the bourgeois philosophers, are to-day working toward a new and grandiose natural philosophy.

NOTES

1. Huet (1630-1721) was a tutor of the Dauphin, and with Bossuet prepared the edition of the classics entitled “In usum Delphini.”-Translator’s Note.

2. Charron, “Discours Chretiens” (1600). The method really appears to be excellent; Kant and others followed it in order to return to Christianity; Socrates and Pyrrho employed it to adapt themsleves to pagan polytheism; for, as the fiery Catholic of the sixteenth century remarked, “so long as absolute scepticism exists, there will be no heresy and no dissenting opinions; an adherent of Pyrrho or of the Academy can never be a heretic, for that is a contradiction.”

3.. G. Le Bon, L’édification de la connaissauce scièntifique (Revue scientifique, February 1, 1908). Le Dantec, Les sensations et le monisme scientifique (Revue scièntifique, February 20, 1904).

4. Sceptical philosopher (First century B. C.).

5. We may cite here some samples of Sophistic criticism: As long as a thing is in one and the same place it is at rest; but a flying arrow is always for one instant at the same place, hence it is at that instant of its flight at rest, consequently also during the whole flight; hence the movement of the arrow is only apparent.

If every existing thing is in space, space itself must be in space and so on to infinity; but since this is inconceivable, nothing existing can be in space. The mathematicians ridicule those who desire to divide a straight line into two equal parts: how can we divide into two equal parts a line which is formed of an odd number of points, nine for instance. We cannot divide the fifth point, since by definition it has no dimensions; but if we do not divide it, the parts are unequal.

We cannot subtract one number from another, for instance 5 from 6: for in order to be able to subtract one thing from another the former must be contained in the latter; but if 5 is contained in 6, so also is 4 contained in 5, 3 in 4, 2 in 3 and 1 in 2; if we add all these the sum is 15; but 15 cannot be subtracted from 6.

6. The Christians of the first centuries cared not at all for their country; the bishop Prudens, who lived in the fourth century, rejoiced that Rome had conquered all peoples and had made the world into one city. On the other hand the Christian poets of the Sibylline proverbs in the second century cherished furious hatred against the rich and against Rome, “the accursed city which spread such unspeakable suffering over the world;” they even hailed its fall in advance, and desired to live to see it. Christianity, which at first had turned only to the disinherited of society, altered its views as it gained over the more wealthy social strata.

7. De Freycinet, “Essai sur la philosophie des sciences” (1895).

8. Savages do not distinguish between object and number; they consider number to be a property of the object, just as civilized men consider heat. electricity and light; later on number becomes separated from objects, so that it becomes an abstract, imaginary being, which is treated like an object. Point, line and surface are in the same manner separated from the body of which they are properties; the point is deprived of three dimensions, the line of two, and the surface of one.

The New Review: A Critical Survey of International Socialism was a New York-based, explicitly Marxist, sometimes weekly/sometimes monthly theoretical journal begun in 1913 and was an important vehicle for left discussion in the period before World War One. Bases in New York it declared in its aim the first issue: “The intellectual achievements of Marx and his successors have become the guiding star of the awakened, self-conscious proletariat on the toilsome road that leads to its emancipation. And it will be one of the principal tasks of The NEW REVIEW to make known these achievements,to the Socialists of America, so that we may attain to that fundamental unity of thought without which unity of action is impossible.” In the world of the East Coast Socialist Party, it included Max Eastman, Floyd Dell, Herman Simpson, Louis Boudin, William English Walling, Moses Oppenheimer, Robert Rives La Monte, Walter Lippmann, William Bohn, Frank Bohn, John Spargo, Austin Lewis, WEB DuBois, Arturo Giovannitti, Harry W. Laidler, Austin Lewis, and Isaac Hourwich as editors. Louis Fraina played an increasing role from 1914 and lead the journal in a leftward direction as New Review addressed many of the leading international questions facing Marxists. International writers in New Review included Rosa Luxemburg, James Connolly, Karl Kautsky, Anton Pannekoek, Lajpat Rai, Alexandra Kollontai, Tom Quelch, S.J. Rutgers, Edward Bernstein, and H.M. Hyndman, The journal folded in June, 1916 for financial reasons. Its issues are a formidable and invaluable archive of Marxist and Socialist discussion of the time.

PDF of full issue: https://www.marxists.org/history/usa/pubs/newreview/1913/v1n19-aug-1913.pdf

PDF of issue 2: https://www.marxists.org/history/usa/pubs/newreview/1913/v1n20-sep-1913.pdf