8. The Organic World. (Conclusion)¶
Core Argument¶
In this concluding chapter on organic nature, Engels delivers a devastating critique of Eugen Dühring’s pretensions to biological erudition, exposing the latter’s ignorance as absolute rather than merely partial. The core argument is that Dühring’s claims to foundational knowledge in natural philosophy are entirely hollow, betrayed by his own vacuous, self-contradictory, and oracularly senseless formulations. Engels proceeds to dismantle Dühring’s biological pronouncements point by point, drawing on the cellular theory that had revolutionised nineteenth-century biology.
Engels first attacks Dühring’s suggestion that the term “composition” should replace “development” in biology. This, Engels argues, reveals that Dühring has not the faintest suspicion of how organic bodies actually form. Engels provides a concise account of cell theory: all organic bodies except the very lowest consist of cells, which multiply by fission. The cell nucleus constricts and divides, followed by the cell itself, a process by which the entire animal develops from the fertilised egg and by which tissues are replaced in the adult. To call this process “composition” rather than development is to demonstrate absolute ignorance of the most fundamental fact of organic life.
Engels then subjects Dühring’s attempted definition of life to merciless logical scrutiny. Dühring proposes four characteristics: real differentiation, circulation of substances through special channels from one internal point, and transmission according to a germ-scheme. Engels shows that these criteria contradict one another and, taken together, would exclude from life not only the entire vegetable kingdom but also about half the animal kingdom, including all polyps, worms, starfish, and even the lancelet. Dühring’s assertion that a single simple type underlies all organisms is equally absurd: the simplest type is the cell, but many lowest organisms—protamoeba, monera, bladder seaweeds—are far below the cellular level, being mere albuminous particles without differentiation.
Engels also takes up Dühring’s claim that sensation is bound up with a nerve apparatus and constitutes the sharp boundary between plant and animal. Engels notes that this is merely a Hegelian “crudity” appropriated as Dühring’s own final truth. He points out that many primitive animals and zoophytes show no trace of a nerve apparatus, and that sensation is not necessarily associated with nerves but with certain albuminous bodies. The existence of transitional forms between plant and animal, which Dühring himself admits, makes his sharp dividing line a logical absurdity. Sensitive plants and insect-eating plants further undermine the claim that plants are devoid of sensation.
Engels then offers his own positive definition: life is the mode of existence of albuminous bodies, consisting essentially in the constant self-renewal of their chemical constituents through metabolism. This metabolism is not merely exchange of matter as such—which occurs in inorganic processes like sulphuric acid manufacture or Traube’s artificial cells—but a self-implementing process inherent in albumen itself. Wherever we find an albuminous body not in dissolution, we find life. Engels acknowledges that this definition is inadequate from a scientific standpoint, but argues it is convenient for ordinary usage.
The chapter concludes with a final polemical flourish: Dühring, faring badly in earthly biology, takes refuge in a starry heaven, claiming the antithesis between pleasure and pain is a universal cosmic key to the universe of sensations. Engels dismisses this as the consolation of a man whose gross blunders in terrestrial science matter little when he carries such a key in his pocket.