Another equally grand idea of the same philosopher is closely connected with his theory of primitive slime, which coincides with the extremely important Protoplasm theory. For Oken, as early as 1809, asserted that the primitive slime produced in the sea by spontaneous generation, at once assumed the form of microscopically small bladders, which he called “Mile,” or “Infusoria.” “Organic nature has for its basis an infinity of such vesicles.” These little bladders arise from original semi-fluid globules of the primitive slime, by the fact of their periphery becoming condensed. The simplest organism, as well as every animal and every plant of higher kind, is nothing else than “an accumulation (synthesis) of such infusorial bladders, which by various combinations assume various forms, and thus develop into higher organisms.” Here again we need only translate the expression little bladder, or infusorium, by the word cell, and we arrive at the Cell theory, one of the grandest biological theories of our century. Schleiden and Schwann, about thirty years ago, were the first to furnish experiential proof that all organisms are either simple cells, or accumulations (syntheses) of such cells, and the more recent protoplasm theory has shown that protoplasm (the original slime) is the most essential (and sometimes the only) constituent part of the genuine cell. The properties which Oken ascribes to his Infusoria are exactly the properties of cells, the properties of elementary beings, by whose accumulation, combination, and varying development, the higher organisms are formed.
These two extremely fruitful thoughts of Oken, on account of the absurd form in which he expressed them, were at first little heeded, or entirely misunderstood, and it was reserved for a much later era to establish them by actual observation. The supposition that the individual species of plants and animals originated from common prototypes by a slow and gradual development of the higher organisms out of lower ones, was of course most closely connected with these ideas. Man’s descent from lower organisms was likewise asserted by Oken—“Man has been developed, not created.” Although many arbitrary perversities and extravagant fancies may be found in Oken’s philosophy of nature, they must not prevent us paying our just admiration to these grand ideas, which were so far in advance of their age. This much is clearly evident from the statements of Goethe and Oken which we have quoted, and from the views of Lamarck and Geoffroy which have to be discussed next, that during the first decade of our century no doctrine approached so nearly to the natural Theory of Descent, newly established by Darwin, as the much decried “Natur-philosophie.”
CHAPTER V.
THEORY OF DEVELOPMENT ACCORDING TO KANT AND LAMARCK.
Kant’s Dualistic Biology.—His Conception of the Origin of Inorganic Nature by Mechanical Causes, of Organic Nature by Causes acting for a Definite Purpose.—Contradiction of this Conception with his leaning towards the Theory of Descent.—Kant’s Genealogical Theory of Development.—Its Limitation by his Teleology.—Comparison of Genealogical Biology with Comparative Philology.—Views in favour of the Theory of Descent entertained by Leopold Buch, Bär, Schleiden, Unger, Schaafhausen, Victor Carus, Büchner.—French Nature-philosophy. —Lamarck’s Philosophie Zoologique.—Lamarck’s Monistic (mechanical) System of Nature.—His Views of the Interaction of the Two Organic Formative Tendencies of Inheritance and Adaptation.— Lamarck’s Conception of Man’s Development from Ape-like Mammals.— Geoffroy St. Hilaire’s , Naudin’s , and Lecoq’s Defence of the Theory of Descent.—English Nature-philosophy.—Views in favour of the Theory of Descent, entertained by Erasmus Darwin, W. Herbert, Grant, Freke, Herbert Spencer, Hooker, Huxley.—The Double Merit of Charles Darwin.
The teleological view of nature, which explains the phenomena of the organic world by the action of a personal Creator acting for a definite purpose, necessarily leads, when carried to its extreme consequences, either to utterly untenable contradictions, or to a twofold (dualistic) conception of nature, which most directly contradicts the unity and simplicity of the supreme laws which are everywhere perceptible. The philosophers who embrace teleology must necessarily assume two fundamentally different natures: an inorganic nature, which must be explained by causes acting mechanically (causæ efficientes), and an organic nature, which must be explained by causes acting for a definite purpose (causæ finales). (Compare p. [34.])
This dualism meets us in a striking manner when considering the conceptions of nature formed by Kant, one of the greatest German philosophers, and his ideas of the coming into being of organisms. A closer examination of these ideas is forced upon us here, because in Kant we honour one of the few philosophers who combine a solid scientific culture with an extraordinary clearness and profundity of speculation. The Königsberg philosopher gained the highest celebrity, not only among speculative philosophers as the founder of critical philosophy, but acquired a brilliant name also among naturalists by his mechanical cosmogeny. Even in the year 1755, in his “General History of Nature, and Theory of the Heavens,”[(22)] he made the bold attempt “to discuss the constitution and the mechanical origin of the whole universe, according to Newton’s principles,” and to explain them mechanically by the natural course of development, to the exclusion of all miracles. This cosmogeny of Kant, or “cosmological gas theory,” which we shall briefly discuss in a future chapter, was at a later day fully established by the French mathematician Laplace and the English astronomer Herschel, and enjoys at the present day almost universal recognition. On account of this important work alone, in which exact knowledge is coupled with most profound speculation, Kant deserves the honourable name of a natural philosopher in the best and purest sense of the word.
If we read Kant’s Criticism of the Teleological Faculty of Judgment, his most important biological work, we perceive that in contemplating organic nature he always maintains what is essentially the teleological or dualistic point of view; whilst for inorganic nature he, unconditionally and without reserve, assumes the mechanical or monistic method of explanation. He affirms that in the domain of inorganic nature all the phenomena can be explained by mechanical causes, by the moving forces of matter itself, but not so in the domain of organic nature. In the whole of Anorganology (in Geology and Mineralogy, in Meteorology and Astronomy, in the physics and chemistry of inorganic natural bodies), all phenomena are said to be explicable merely by mechanism (causa efficiens), without the intervention of a final purpose. In the whole domain of Biology, on the other hand—in Botany, Zoology, and Anthropology—mechanism is not considered sufficient to explain to us all their phenomena; but we are supposed to be able to comprehend them only by an assumption of a final cause acting for a definite purpose (causa finalis). In several passages Kant emphatically remarks that, from a strictly scientific point of view, all phenomena, without exception, require a mechanical interpretation, and that mechanism alone can offer a true explanation. But at the same time he thinks, that in regard to living natural bodies, animals and plants, our human power of comprehension is limited, and not sufficient for arriving at the real cause of organic processes, especially at the origin of organic forms. The right of human reason to explain all phenomena mechanically is unlimited, he says, but its power is limited by the fact that organic nature can be conceived only from a teleological point of view.