Friedrich Engels, answered from the texts and cited to the page.
Dühring spent considerable energy attacking this law, and in doing so demonstrated precisely that he could not escape it. The negation of the negation is a law of development — not a mystical formula borrowed from Hegel's theology, but a description of how natural and historical processes actually move.1 Consider the grain of barley: it germinates, the original grain is negated, and from that negation grows the plant, which in turn produces many grains — a restoration on a higher level.
The integral calculus follows the same logical form. Geological strata are deposited, eroded, redeposited. Species are negated by speciation. What I am identifying in all these cases is not some secret essence shared between barley and mathematics; I am identifying the common form of a developmental process.1 To say that all these constitute negation of the negation is to embrace them under one law of progress while leaving the specific character of each process to be studied on its own terms.
The dialectic, properly understood, is nothing but the science of the universal laws of motion and evolution in nature, human society, and thought.1 Dühring's objection to the way Marx used this law in the historical sketch of primitive accumulation was that Marx was substituting Hegelian wordplay for genuine analysis.2 Marx traces how scattered individual property — the peasant's direct relation to his means of production — was expropriated by capital from the sixteenth century onward: that is the first negation.
The development of capitalist production itself socializes the labor process while concentrating ownership in fewer hands, until the expropriation of the expropriators becomes possible: that is the second negation, the negation of the negation.3 What results is not a return to the original individual property but a restoration of individual property on the basis of the acquisitions of the capitalist era — cooperative labor, common ownership of land and instruments.3
Dühring reads this as religious analogy: Hegel's first negation is the Fall, his second is Redemption, and therefore Marx is doing theology in economic costume.4 The charge is a conjuror's trick. The fact that a logical form appears in religious mythology does not disqualify it from appearing in nature and history as well. Friction is a process; the fact that some mystic once described sin as a kind of friction does not make mechanics into theology.
What Dühring cannot account for is that the developmental sequence Marx traces in the history of English capital is documented — in the parliamentary enclosure acts, in the destruction of the peasantry, in the concentration of land ownership, in the factory system. The negation of the negation does not produce the necessity of communism by logical sleight of hand; it names the form of a historical process whose content is established by the evidence.
The law is thus neither a metaphysical imposition on reality nor a mere pedagogical convenience. It is a feature of processes that actually occur, at every scale where we have the patience to observe development over time.
It is a very far reaching, and, just, for this reason, a very important law of development of nature, human history and thought, a law which we see realised in the animal and vegetable kingdoms, in geology, in mathematics, in history, and philosophy... The dialectic is, as a matter of fact, nothing but the science of the universal laws of motion, and evolution in nature, human society and thought.Landmarks of Scientific Socialism - Anti-Duhring
The Hegelian negation of the negation is called upon to serve here as a midwife, in default of anything better and clearer, and by means of it the future is brought into existence from the present.Landmarks of Scientific Socialism - Anti-Duhring
Marx says: 'It is the negation of negation. This re-establishes individual property for the producer, but based on the acquisitions of the capitalist era, on the co-operation of free workers and on their common property in land and in the means of production produced by labor itself.'Anti-Dühring, p. 141
For the benefit of the reader who is not familiar with these tricks, it must be expressly pointed out that Hegel's first negation is the catechismal idea of the fall from grace, and his second is that of a higher unity leading to redemption. The logic of facts can hardly be based on this farcical analogy borrowed from the religious sphere.Anti-Dühring, pp. 140–141