Engels' Dialectics of Nature
It is, therefore, from the history of nature and human society thatthe laws of dialectics are abstracted. For they are nothing but the mostgeneral laws of these two aspects of historical development, as well asof thought itself. And indeed they can be reduced in the main to three:
The law of the transformation of quantity into quality andvice versa;
The law of the interpenetration of opposites;
The law of the negation of the negation.
All three are developed by Hegel in his idealist fashion as mere lawsofthought: the first, in the first part of hisLogic, intheDoctrine of Being; the second fills the whole of the secondand by far the most important part of hisLogic, theDoctrineof Essence; finally the third figures as the fundamental law for theconstruction of the whole system. The mistake lies in the fact that theselaws are foisted on nature and history as laws of thought, and not deducedfrom them. This is the source of the whole forced and often outrageoustreatment; the universe, willy-nilly, is made out to be arranged in accordancewith a system of thought which itself is only the product of a definitestage of evolution of human thought. If we turn the thing round, then everythingbecomes simple, and the dialectical laws that look so extremely mysteriousin idealist philosophy at once become simple and clear as noonday.
Moreover, anyone who is even only slightly acquainted with his Hegelwill be aware that in hundreds of passages Hegel is capable of giving themost striking individual illustrations from nature and history of the dialecticallaws.
We are not concerned here with writing a handbook of dialectics, butonly with showing that the dialectical laws are really laws of developmentof nature, and therefore are valid also for theoretical natural science.Hence we cannot go into the inner interconnection of these laws with oneanother.
1.The law of the transformation of quantity into quality andviceversa. For our purpose, we could express this by saying that in nature,in a manner exactly fixed for each individual case, qualitative changescan only occur by the quantitative addition or subtraction of matter ormotion (so-called energy).
All qualitative differences in nature rest on differences of chemicalcomposition or on different quantities or forms of motion (energy) or,as is almost always the case, on both. Hence it is impossible to alterthe quality of a body without addition or subtraction of matter or motion,i.e. without quantitative alteration of the body concerned. In this form,therefore, Hegel's mysterious principle appears not only quite rationalbut even rather obvious.
It is surely hardly necessary to point out that the various allotropicand aggregational states of bodies, because they depend on various groupingsof the molecules, depend on greater or lesser quantities of motion communicatedto the bodies.
But what is the position in regard to change of form of motion, or so-calledenergy? If we change heat into mechanical motion orvice versa,is not the quality altered while the quantity remains the same? Quite correct.But it is with change of form of motion as with Heine's vices; anyone canbe virtuous by himself, for vices two are always necessary. Change of formof motion is always a process that takes place between at least two bodies,of which one loses a definite quantity of motion of one quality (e.g. heat),while the other gains a corresponding quantity of motion of another quality(mechanical motion, electricity, chemical decomposition). Here, therefore,quantity and quality mutually correspond to each other. So far it has notbeen found possible to convert motion from one form to another inside asingle isolated body.
We are concerned here in the first place with nonliving bodies; thesame law holds for living bodies, but it operates under very complex conditionsand at present quantitative measurement is still often impossible for us.
If we imagine any non-living body cut up into smaller and smaller portions,at first no qualitative change occurs. But this has a limit: if we succeed,as by evaporation, in obtaining the separate molecules in the free state,then it is true that we can usually divide these still further, yet onlywith a complete change of quality. The molecule is decomposed into itsseparate atoms, which have quite different properties from those of themolecule. In the case of molecules composed of various chemical elements,atoms or molecules of these elements themselves make their appearance inthe place of the compound molecule; in the case of molecules of elements,the free atoms appear, which exert quite distinct qualitative effects:the free atoms of nascent oxygen are easily able to effect what the atomsof atmospheric oxygen, bound together in the molecule, can never achieve.
But the molecule is also qualitatively different from the mass of thebody to which it belongs. It can carry out movements independently of thismass and while the latter remains apparently at rest, e.g. heat oscillations;by means of a change of position and of connection with neighbouring moleculesit can change the body into an allotrope or a different state of aggregation.
Thus we see that the purely quantitative operation of division has alimit at which it becomes transformed into a qualitative difference: themass consists solely of molecules, but it is something essentially differentfrom the molecule, just as the latter is different from the atom. It isthis difference that is the basis for the separation of mechanics, as thescience of heavenly and terrestrial masses, from physics, as the mechanicsof the molecule, and from chemistry, as the physics of the atom.
In mechanics, no qualities occur; at most, states such as equilibrium,motion, potential energy, which all depend on measurable transference ofmotion and are themselves capable of quantitative expression. Hence, inso far as qualitative change takes place here, it is determined by a correspondingquantitative change.
In physics, bodies are treated as chemically unalterable or indifferent;we have to do with changes of their molecular states and with the changeof form of the motion which in all cases, at least on one of the two sides,brings the molecule into play. Here every change is a transformation ofquantity into quality, a consequence of the quantitative change of thequantity of motion of one form or another that is inherent in the bodyor communicated to it. "Thus, for instance, the temperature of water isfirst of all indifferent in relation to its state as a liquid; but by increasingor decreasing the temperature of liquid water a point is reached at whichthis state of cohesion alters and the water becomes transformed on theone side into steam and on the other into ice." (Hegel, Encyclopedia,Collected Works, VI, p. 217.) Similarly, a definite minimum current strengthis required to cause the platinum wire of an electric incandescent lampto glow; and every metal has its temperature of incandescence and fusion,every liquid its definite freezing and boiling point at a given pressure - in so far as our means allow us to produce the temperature required;finally also every gas has its critical point at which it can be liquefiedby pressure and cooling. In short, the so-called physical constants arefor the most part nothing but designations of the nodal points at whichquantitative addition or subtraction of motion produces qualitative alterationin the state of the body concerned, at which, therefore, quantity is transformedinto quality.
The sphere, however, in which the law of nature discovered by Hegelcelebrates its most important triumphs is that of chemistry. Chemistrycan be termed the science of the qualitative changes of bodies as a resultof changed quantitative composition. That was already known to Hegel himself(Logic, Collected Works, III, p. 488). As in the case of oxygen:if three atoms unite into a molecule, instead of the usual two, we getozone, a body which is very considerably different from ordinary oxygenin its odour and reactions. Again, one can take the various proportionsin which oxygen combines with nitrogen or sulphur, each of which producesa substance qualitatively different from any of the others! How differentlaughing gas (nitrogen monoxide N2O) is from nitric anhydride (nitrogenpentoxide, N2O5) ! The first is a gas, the second at ordinary temperaturesa solid crystalline substance. And yet the whole difference in compositionis that the second contains five times as much oxygen as the first, andbetween the two of them are three more oxides of nitrogen (N0, N2O3, NO2),each of which is qualitatively different from the first two and from eachother.
This is seen still more strikingly in the homologous series of carboncompounds, especially in the simpler hydrocarbons. Of the normal paraffins,the lowest is methane, CH4; here the four linkages of the carbon atom aresaturated by four atoms of hydrogen. The second, ethane, C2H6, has twoatoms of carbon joined together and the six free linkages are saturatedby six atoms of hydrogen. And so it goes on, with C3H8, C4H10, etc., accordingto the algebraic formula CnH2n+2, so that by each addition of CH2 a bodyis formed that is qualitatively distinct from the preceding one. The threelowest members of the series are gases, the highest known, hexadecane,C16H34, is a solid body with a boiling point of 270º C. Exactly thesame holds good for the series of primary alcohols with formula CnH2n+20,derived (theoretically) from the paraffins, and the series of monobasicfatty acids (formula CnH2nO2). What qualitative difference can be causedby the quantitative addition of C3H6 is taught by experience if we consumeethyl alcohol, C2H12O, in any drinkable form without addition of otheralcohols, and on another occasion take the same ethyl alcohol but witha slight addition of amyl alcohol, C5H12O, which forms the main constituentof the notorious fusel oil. One's head will certainly be aware of it thenext morning, much to its detriment; so that one could even say that theintoxication, and subsequent "morning after" feeling, is also quantitytransformed into quality, on the one hand of ethyl alcohol and on the otherhand of this added C3H6.
In these series we encounter the Hegelian law in yet another form. Thelower members permit only of a single mutual arrangement of the atoms.If, however, the number of atoms united into a molecule attains a sizedefinitely fixed for each series, the grouping of the atoms in the moleculecan take place in more than one way; so that two or more isomeric substancescan be formed, having equal numbers of C, H, and 0 atoms in the moleculebut nevertheless qualitatively distinct from one another. We can even calculatehow many such isomers are possible for each member of the series. Thus,in the paraffin series, for C4H10 there are two, for C6H12 there are three;among the higher members the number of possible isomers mounts very rapidly.Hence once again it is the quantitative number of atoms in the moleculethat determines the possibility and, in so far as it has been proved, alsothe actual existence of such qualitatively distinct isomers.
Still more. From the analogy of the substances with which we are acquaintedin each of these series, we can draw conclusions as to the physical propertiesof the still unknown members of the series and, at least for the membersimmediately following the known ones, predict their properties, boilingpoint, etc., with fair certainty.
Finally, the Hegelian law is valid not only for compound substancesbut also for the chemical elements themselves. We now know that "the chemicalproperties of the elements are a periodic function of their atomic weights"(Roscoe-Schorlemmer,Complete Text-Book of Chemistry, II, p. 823),and that, therefore, their quality is determined by the quantity of theiratomic weight. And the test of this has been brilliantly carried out. Mendeleyevproved that various gaps occur in the series of related elements arrangedaccording to atomic weights indicating that here new elements remain tobe discovered. He described in advance the general chemical propertiesof one of these unknown elements, which he termed eka-aluminium, becauseit follows after aluminium in the series beginning with the latter, andhe predicted its approximate specific and atomic weight as well as itsatomic volume. A few years later, Lecoq de Boisbaudran actually discoveredthis element, and Mendeleyev's predictions fitted with only very slightdiscrepancies. Eka-aluminium was realised in gallium (ibid., p. 828). Bymeans of the - unconscious - application of Hegel's law of the transformationof quantity into quality, Mendeleyev achieved a scientific feat which itis not too bold to put on a par with that of Leverrier in calculating theorbit of the still unknown planet Neptune.
In biology, as in the history of human society, the same law holds goodat every step, but we prefer to dwell here on examples from the exact sciences,since here the quantities are accurately measurable and traceable.
Probably the same gentlemen who up to now have decried the transformationof quantity into quality as mysticism and incomprehensible transcendentalismwill now declare that it is indeed something quite self-evident, trivial,and commonplace, which they have long employed, and so they have been taughtnothing new.
But to have formulated for the first time in its universally valid forma general law of development of nature, society, and thought, will alwaysremain an act of historic importance. And if these gentlemen have for yearscaused quantity and quality to be transformed into one another, withoutknowing what they did, then they will have to console themselves with Moliere'sMonsieur Jourdain who had spoken prose all his life without having theslightest inkling of it.
Contents |next section |Marx Engels Archive