Karl Marx
The Difference Between the Democritean and Epicurean Philosophy of Nature
Part II: On the Difference between Democritean and Epicurean Physics In Detail

Chapter One: The Declination of the Atom from the Straight Line


Epicurus assumes a threefold motion of the atoms in the void.(1) One motion is the fall in a straight line, the second originates in the deviation of the atom from the straight line, and the third is established through the repulsion of the many atoms. Both Democritus and Epicurus accept the first and the third motion. The declination of the atom from the straight line differentiates the one from the other.(2)

This motion of declination has often been made the subject of a joke. Cicero more than any other is inexhaustible when he touches on this theme. Thus we read in him, among other things:

“Epicurus maintains that the atoms are thrust downwards in a straight line by their weight; this motion is said to he the natural motion of bodies. But then it occurred to him that if all atoms were thrust downwards, no atom could ever meet another one. Epicurus therefore resorted to a lie. He said that the atom makes a very tiny swerve, which is, of course, entirely impossible. From this arose complexities, combinations and adhesions of the atoms with one another, and out of this came the world, all parts of it and its contents. Besides all this being a puerile invention, he does not even achieve what he desires."(3)

We find another version in the first book of Cicero's treatise On the Nature of the Gods:

“Since Epicurus saw that, if the atoms travelled downwards by their own weight, nothing would be within our control, for their motion would be determined and necessary, he invented a means for escaping this necessity, a means which had escaped the notice of Democritus. He says that the atom, although thrust downwards by its weight and gravity, makes a very slight swerve. To assert this is more disgraceful than to he incapable of defending what he wants."(4)

Pierre Bayle expresses a similar opinion:

“Before him” (i.e., Epicurus) “only the motion of weight and that of reflection were conceded to the atom.... Epicurus supposed that even in the midst of the void the atoms declined slightly from the straight line, and from this, he said, arose freedom.... It must he noted, in passing, that this was not the only motive that led him to invent this motion of declination. He also used it to explain the meeting of atoms; for he saw clearly that supposing they fall] move with equal speed downwards along straight lines, he would never be able to explain that they could meet, and that thus the creation of the world would have been impossible. It was necessary, then, that they should deviate from the straight line."(5)

For the present I leave the validity of these reflections an open question. This much everyone will notice in passing, that the most recent critic of Epicurus, Schaubach, has misunderstood Cicero when he says:

“The atoms are all thrust downwards by gravity, hence parallel, owing to physical causes, but through mutual repulsion they acquire another motion, according to Cicero (De nature deorum, I, xxv [, 69]) an oblique motion due to accidental causes, and indeed from all eternity."(6)

In the first place, Cicero in the quoted passage does not make the repulsion the reason for the oblique direction, but rather the oblique direction the reason for the repulsion. In the second place, he does not speak of accidental causes, but rather criticises the fact that no causes at all are mentioned, as it would be in and for itself contradictory to assume repulsion and at the same time accidental causes as the reason for the oblique direction. At best one could then still speak of accidental causes of the repulsion, but not of accidental causes of the oblique direction.

For the rest, one peculiarity in Cicero's and Bayle's reflections is too obvious not to be stressed immediately. They foist upon Epicurus motives of which the one nullifies the other. Epicurus is supposed to have assumed a declination of the atoms in order to explain the repulsion on one occasion, and on another freedom. But if the atoms do not meet without declination, then declination as an explanation of freedom is superfluous; for the opposite of freedom begins, as we see in Lucretius,(7) only with the deterministic and forced meeting of atoms. But if the atoms meet without declination, then this is superfluous for explaining repulsion. 1 maintain that this contradiction arises when the causes for the declination of the atom from the straight line are understood so superficially and disconnectedly as they are by Cicero and Bayle. We shall find in Lucretius, the only one in general of all the ancients who has understood Epicurean physics, a more profound exposition.

We now shall consider the declination itself.

Just as the point is negated [aufgehoben] in the line, so is every failing body negated in the straight line it describes. its specific quality does not matter here at all. A falling apple describes a perpendicular line just as a piece of iron does. Every body, insofar as we are concerned with the motion of falling, is therefore nothing but a moving point, and indeed a point without independence, which in a certain mode of being-the straight line which it describes-surrenders its individuality [Einzelheit]. Aristotle therefore is correct when he objects against the Pythagoreans: “You say that the motion of the line is the surface, that of the point the line; then the motions of the monads will also be lines."(8) The consequence of this for the monads as well as for the atoms would therefore be-since they are in constant motion(9) — that neither monads nor atoms exist, but rather disappear in the straight line; for the solidity of the atom does not even enter into the picture, insofar as it is only considered as something falling in a straight line. To begin with, if the void is imagined as spatial void, then the atom is the immediate negation of abstract space, hence a spatial point. The solidity, the intensity, which maintains itself in itself against the incohesion of space, can only he added by virtue of a principle which negates space in its entire domain, a principle such as time is in real nature. Moreover, if this itself is not admitted, the atom, insofar as its motion is a straight line, is determined only by space and is prescribed a relative being and a purely material existence. But we have seen that one moment in the concept of the atom is that of being pure form, negation of all relativity, of all relation to another mode of being. We have noted at the same time that — Epicurus objectifies for himself both moments which, although they contradict one another, are nevertheless inherent in the concept of the atom.

How then can Epicurus give reality to the pure form-determination of the atom, the concept of pure individuality, negating any mode of being determined by another being?

Since he is moving in the domain of immediate being, all determinations are immediate. Opposite determinations are therefore opposed to one another as immediate realities.

But the relative existence which confronts the atom, the mode of being which it has to negate, is the straight line. The immediate negation of this motion is another motion, which, therefore, spatially conceived, is the declination from the straight line.

The atoms are purely self-sufficient bodies or rather bodies conceived in absolute self-sufficiency, like the heavenly bodies. Hence, again like the heavenly bodies, they move not in straight, but in oblique lines. The motion of failing is the motion of non-self-sufficiency.

If Epicurus therefore represents the materiality of the atom in terms of its motion along a straight line, he has given reality to its form-determination in the declination from the straight line, and these opposed determinations are represented as directly opposed motions.

Lucretius therefore is correct when he maintains that. the declination breaks the fati foedera, [bonds of fate](10) and, since he applies this immediately to consciousness,(11) it can be said of the atom that the declination is that something in its breast that can fight back and resist.

But when Cicero reproaches Epicurus that

“he does not even attain the goal for which he made all this up -for if all atoms declined, none of them would ever combine, or some would deviate, others would be driven straight ahead by their motion. So it would be necessary as it were to give the atoms definite assignments beforehand: which had to move straight ahead and which obliquely”,(12)

this objection has the justification that the two moments inherent in the concept of the atom are represented as directly different motions, and therefore must be allotted to different individuals: an inconsistency, but a consistent one, since the domain of the atom is immediacy.

Epicurus feels this inherent contradiction quite well. He therefore endeavours to represent the declination as being as imperceptible as possible to the senses; it takes place

In time, in place unfixt (Lucretius, De rerum nature, II, 294). (13)

it occurs in the smallest possible space.(14)

Moreover Cicero, (15) and, according to Plutarch, several ancient authors,(16) reproach Epicurus for saying that the declination of the atom occurs without cause. Nothing more disgraceful, says Cicero, can happen to a physicist.(17) But, in the first place, a physical cause such as Cicero wants would throw the declination of the atom back into the domain of determinism, out of which it was precisely to be lifted. And then, the atom is by no means complete before it has been submitted to the determination of declination. To inquire after the cause of this determination means therefore to inquire after the cause that makes the atom a principle-a clearly meaningless inquiry to anyone for whom the atom is the cause of everything, hence without cause itself.

Finally, Bayle,(18)-supported by the authority of Augustine,(19) who states that Democritus ascribed to the atom a spiritual principle — an authority, by the way, who in contrast to Aristotle and the other ancients is without any importance-reproaches Epicurus for having thought out the concept of declination instead of this spiritual principle. But, on the contrary, merely a word would have been gained with this “soul of the atom", whereas the declination represents the real soul of the atom, the concept of abstract individuality.

Before we consider the consequence of the declination of the atom from the straight line, we must draw attention to another, most important element, which up to now has been entirely overlooked.

The declination of the atom from the straight line is, namely, not a particular determination which appears accidentally in Epicurean physics. On the contrary, the law which it expresses goes through the whole Epicurean philosophy, in such a way, however, that, as goes without saying, the determination of its appearance depends on the domain in which it is applied.

As a matter of fact, abstract individuality can make its concept, its form-determination, the pure being-for-itself, the independence from immediate being, the negation of all relativity, effective only by abstracting from the being that confronts it; for in order truly to overcome it, abstract individuality had to idealise it, a thing only generality can accomplish.

Thus, while the atom frees itself from its relative existence, the straight line, by abstracting from it, by swerving away from it; so the entire Epicurean philosophy swerves away from the restrictive mode of being wherever the concept of abstract individuality, self-sufficiency and negation of all relation to other things must be represented in its existence.

The purpose of action is to be found therefore in abstracting, swerving away from pain and confusion, in ataraxy. (20) Hence the good is the flight from evil,(21) pleasure the swerving away from suffering.(22) Finally, where abstract individuality appears in its highest freedom and independence, in its totality, there it follows that the being which is swerved away from, is all being., for this reason, the gods swerve away from the world, do not bother with it and live outside it.(23)

These gods of Epicurus have often been ridiculed, these gods who, like human beings, dwell in the intermundia [The spaces between the worlds, literally: inter-worlds] of the real world, have no body but a quasi-body, no blood but quasi-blood,(24) and, content to abide in blissful peace, lend no car to any supplication, are unconcerned with us and the world, are honoured because of their beauty, their majesty and their superior nature, and not for any gain.

And yet these gods are no fiction of Epicurus. They did exist. They are the Elastic gods of Greek art.[23] Cicero, the Roman, rightly scoffs at them,(25) but Plutarch, the Greek, has forgotten the whole Greek outlook when he claims that although this doctrine of the gods does away with fear and superstition, it produces no joy or favour in the gods, but instead bestows on us that relation to them that we have to the Hyrcanian [24] fish, from which we expect neither harm nor advantage.(26) Theoretical calm is one of the chief characteristics of the Greek gods. As Aristotle says:

“What is best has no need of action, for it is its own end."(27)

We now consider the consequence that follows directly from the declination of the atom. In it is expressed the atom's negation of all motion and relation by which it is determined as a particular mode of being by another being. This is represented in such a way that the atom abstracts from the opposing being and withdraws itself from it. But what is contained herein, namely, its negation of all relation to something else, must be realised, positively established. This can only be done if the being to which it relates itself is none other than itself, hence equally an atom, and, since it itself is directly determined, many atoms. The repulsion of the many atoms is therefore the necessary realisation of the lex atomi, [Law of the atom] as Lucretius calls the declination. But since here every determination is established as a particular being, repulsion is added as a third motion to the former ones. Lucretius is therefore correct when he says that, if the atoms were not to decline, neither their repulsion nor their meeting would have taken place, and the world would never have been created.(28) For atoms are their own sole object and can only be related to themselves, hence speaking in spatial terms, they can only meet, because every relative existence of these atoms by which they would be related to other beings is negated. And this relative existence is, as we have seen, their original motion, that of falling in a straight line. Hence they meet only by virtue of their declination from the straight line. It has nothing to do with merely material fragmentation.(29)

And in truth: the immediately existing individuality is only realised conceptually, inasmuch as it relates to something else which actually is itself — even when the other thing confronts it in the form of immediate existence. Thus man ceases to he a product of nature only when the other being to which he relates himself is not a different existence but is itself an individual human being, even if it is not yet the mind [Geist]. But for man as man to become his own real object, he must have crushed within himself his relative being, the power of desire and of mere nature. Repulsion is the first form of self-consciousness, it corresponds therefore to that self-consciousness which conceives itself as immediate-being, as abstractly individual.

The concept of the atom is therefore realised in repulsion, inasmuch as it is abstract form, but no less also the opposite, inasmuch as it is abstract matter; for that to which it relates itself consists, to be true, of atoms, but other atoms. But when I relate myself to myself as to something which is directly another, then my relationship is a material one. This is the most extreme degree of externality that can be conceived. In the repulsion of the atoms, therefore, their materiality, which was posited in the fall in a straight line, and the form-determination, which was established in the declination, are united synthetically.

Democritus, in contrast to Epicurus, transforms into an enforced motion, into an act of blind necessity, that which to Epicurus is the realisation of the concept of the atom. We have already seen above that he considers the vortex (dini) resulting from the repulsion and collision of the atoms to be the substance of necessity. He therefore sees in the repulsion only the material side, the fragmentation, the change, and not the ideal side, according to which all relation to something else is negated and motion is established as self-determination. This can be clearly seen from the fact that he conceives one and the same body divided through empty space into many parts quite sensuously, like gold broken up into pieces.(30) Thus he scarcely conceived of the One as the concept of the atom.

Aristotle correctly argues against him:

“Hence Leucippus and Democritus, who assert that the primary bodies always moved in the void and in the infinite, should say what kind of motion this is, and what is the motion natural to them. For if each of the elements is forcibly moved by the other, then it is still necessary that each should have also a natural motion, outside which is the enforced one. And this first motion must not be enforced but natural. Otherwise the procedure goes on to infinity."(31)

The Epicurean declination of the atom thus changed the whole inner structure of the domain of the atoms, since through it the form-determination is validated and the contradiction inherent in the concept of the atom is realised. Epicurus was therefore the first to grasp the essence of the repulsion — even if only in sensuous form, whereas Democritus only knew of its material existence.

Hence we find also more concrete forms of the repulsion applied by Epicurus. In the political domain there is the covenant,(32) in the social domain friendship, which is praised as the highest good.


Part II, Chapter 2: The Qualities of the Atom


(1) Stobaeus, Physical Selections, 1, p. 33. Epicurus says ... that the atoms move sometimes vertically downwards, at other times by deviating from a straight fine, but the motion upward is due to collision and recoil.

Comp. Cicero, On the Highest Goods and Evils, I, vi. (Plutarch,) On the Sentiments of the Philosophers, p. 249 [I, 12]. Stobaeus, 1.c., p. 40.

(2) Cicero, On the Nature of the Gods, 1, xxvi [73]. What is there in Epicurus' natural philosophy that does not come from Democritus? Since even if he introduced some alterations, for instance the swerve of the atoms of which I spoke just now ...

(3) Cicero, On the Highest Goods and Evils, I, vi [18-19]. He (Epicurus) believes that these same indivisible solid bodies are borne by their own weight perpendicularly downward, which he holds is the natural motion of all bodies; but thereupon this clever fellow, encountering the difficulty that if they all travelled downwards in a straight fine, and, as I said, perpendicularly, no one atom would ever he able to overtake any other atom, accordingly introduced an idea of his own invention: he said that the atom makes a very tiny swerve,- the smallest divergence possible; and so are produced entanglements and combinations and cohesions of atoms with atoms, which result in the creation of the world and all its parts, and of all that is in them.

(4) Cicero, On the Nature of the Gods, I, xxv [69-70]. Epicurus saw that if the atoms travelled downwards by their own weight, we should have no freedom of the will, since the motion of the atoms would he determined by necessity. He therefore invented a device to escape from determinism (the point had apparently escaped the notice of Democritus): he said that the atom while travelling vertically downward by the force of gravity makes a very slight swerrve to one side. This defence discredits him more than if he had had to abandon his original position. Comp. Cicero, On Fate, x [22-23].

(5) Bayle, Dictionnaire historique et critique (Historical and Critical Dictionary), art. Epicurus.

(6) Schaubach, On Epicurus' Astronomical Concepts [in German], in Archiv für Philologie und Pédagogie, V, 4, [1839,] p. 549.

(7) Lucretius, On the Nature of Things, 11, 251 ff. Again, if all movement is always interconnected, the new rising from the old in a determinate order ... what is the source of the free will?

(8) Aristotle, On the Soul, I, 4 [409, 1-5]. How are we to imagine a unit [monad] being moved? By what agency? What sort of movement can be attributed to what is without parts or internal differences? If the unit is both originative of movement and itself capable of being moved, it must contain differences. Further, since they say a moving line generates a surface and a moving point a line, the movements of the psychic units must be lines.

(9) Diogenes Laertius, X, 43. The atoms are in continual motion.

Simplicius, 1.c., p. 424. ... the followers of Epicurus ... [taught] eternal motion.

(10) Lucretius, On the Nature of Things, 11, 251, 253-255. ... if the atoms never swerve so as to originate some new movement that will snap the bonds of fate, the everlasting sequence of cause and effect....

(11) Ibid., II, 279-280. ... there is within the human breast something that can fight against this force and resist it.

(12) Cicero, On the Highest Goods and Evils, I, vi [19-20]. ... yet he does not attain the object for the sake of which this fiction was devised. For, if all the atoms swerve, none will ever come to cohere together; or if some swerve while others travel in a straight line, by their own natural tendency, in the first place this will be tantamount to assigning to the atoms their different spheres of action, some to travel straight and some sideways....

(13) Lucretius, 1.c., 293.

(14) Cicero, On Fate, x [22]. ... when the atom swerves sideways a minimal space, termed [by Epicurus] elachiston [the smallest].

(15) Ibid. Also he is compelled to profess in reality, if not quite explicitly, that this swerve takes place without cause....

(16) Plutarch, On the Creation of the Soul, VI (VI, p. 8, stereotyped edition). For they do not agree with Epicurus that the atom swerves somewhat, since he introduces a motion without cause out of the non-being.

(17) Cicero, On the Highest Goods and Evils, I, vi [191. The swerving is itself an arbitrary fiction (for Epicurus says the atoms swerve without a cause, yet this is a capital offence in a natural philosopher, to speak of something taking place uncaused]. Then also he gratuitously deprives the atoms of what he himself declared to be the natural motion of all heavy bodies, namely, movement in a straight line downwards....'

(18) Bayle, 1.c.

(19) Augustine, Letter 56.

(20) Diogenes Laertius, X, 128. For the end of all our actions is to be free from pain and fear.

(21) Plutarch, That Epicurw Actually Makes a Pleasant Life Impossible, 1091. Epicurus too makes a similar statement to the effect that the Good is a thing that arises out of your very escape from evil....

(22) Clement of Alexandria, The Miscellanies, II, p. 415 [21]. ... Epicurus also says that the removal of pain is pleasure....

(23) Sencea, On Benefits, IV [,4, 11, p. 699. Yes, and therefore God does not give benefits, but, free from all care and unconcerned about us, he turns his back on the world... and benefits no more concern him than injuries....

(24) Cicero, on the Nature of the Gods, 1, xxiv [681. ... you gave us the formula just now -God has not body but a semblance of body, not blood but a kind of blood.

(25) ibid.. xi [112, 115-116]. Well then, what meat and drink, what harmonies of music and flowers of various colours, what delights of touch and smell will you assign to the gods, so as to keep them steeped in pleasure?... Why, what reason have you for maintaining that men owe worship to the gods, if the gods not only pay no regard to men, but care for nothing and do nothing at all? “But deity possesses an excellence and pre-eminence which must of its own nature attract the worship of the wise.” Now how can there be any excellence in a being so engrossed in the delights of his own pleasure that he always has been, is, and will continue to be entirely idle and inactive?

(26) Plutarch, That Epicurus Actually Makes a Pleasant Life Impossible, [1100-] 1101. ... their theory ... does remove a certain superstitious fear; but it allows no joy and delight to come to us from the gods. Instead, it puts us in the same state of mind with regard to the gods, of neither being alarmed nor rejoicing, that we have regarding the Hyrcanian fish. We expect nothing from them either good or evil.

(27) Aristotle, On the Heavens, If, 12 [292 4 -6]. ... while the perfectly conditioned has no need of action, since it is itself the end....

(28) Lucretius, On the Nature of Things, 11, 221, 223-224. If it were not for this swerve, everything would fall downwards like rain-drops through the abyss of space. No collision would take place and no impact of atom on atom would he created anything. created. Thus nature would never have

(29) Ibid., II, 284-292. So also in the atoms ... besides weight and impact there must be a third cause of movement, the source of this inborn power of ours....

But the fact that the mind itself has no internal necessity to determine its every act and compel it to suffer in helpless passivity-this is due to the slight swerve of the atoms....

(30) Aristotle, On the Heavens, I, 7 -276a, 11. If the whole is not [275 30-276, 1] If the whole is not continuous, but exists, as Democritus and Leucippus think, in the form of parts separated by void, there must necessarily be one movement of all the multitude. ... but their nature is one, like many pieces of gold separated from one another.

(31) Ibid., III, 2 [300, 9-17]. Hence Leucippus and Democritus, who say that the primary bodies are in perpetual movement in the void or infinite, may be asked to explain the manner of their motion and the kind of movement which is natural to them. For if the various elements are constrained by one another to move as they do, each must still have a natural movement which the constrained contravenes, and the prime mover must cause motion not by constraint but naturally. If there is no ultimate natural cause of movement and each preceding term in the series is always moved by constraint, we shall have an infinite process.

(32) Diogones Laertius, X, 150. Those animals which are incapable of making covenants with one another, to the end that they may neither inflict nor suffer harm, are without either justice or injustice. And those tribes which either could not or would not form mutual covenants to the same end are in like case. There never was an absolute justice, but only an agreement made in reciprocal intercourse, in whatever localities, now and again, from time to time, providing against the infliction or suffering of harm.