href="@public@vhost@g@gutenberg@html@files@25711@[email protected]#FNanchor_1_8" class="pginternal" tag="{http://www.w3.org/1999/xhtml}a">[8] "Wer die Wahrheit kennet und saget sie frei,
Der kommt in Berlin auf die Stadt-Vogtei."

CONTENTS.

FREEDOM IN SCIENCE AND TEACHING.

CHAPTER I.

DEVELOPMENT AND CREATION.

Nothing is more helpful for the understanding of scientific controversies, or for the clearing of confused conceptions, than a contrasted statement, as defined and clear as possible, of the simplest leading propositions of the contending doctrines. Hence it is highly favourable to the victory of our modern doctrine of evolution that its chief problem, the question as to the origin of species, is being more and more pressed by these opposite alternatives: Either all organisms are naturally evolved, and must in that case be all descended from the simplest common parent-forms—or: That is not the case, and the distinct species of organisms have originated independently of each other, and in that case can only have been created in a supernatural way, by a miracle. Natural evolution, or supernatural creation of species—we must choose one of these two possibilities, for a third there is not.

But as Virchow, like many other opponents of the doctrine of evolution, constantly confounds this latter proposition with the doctrine of descent, and that again with Darwinism, it will not be superfluous to indicate here, in a few words, the limitation and subordination of these three great theories.

I. The general doctrine of development, the progenesis-theory or evolution-hypothesis (in the widest sense), as a comprehensive philosophical view of the universe, assumes that a vast, uniform, uninterrupted and eternal process of development obtains throughout all nature; and that all natural phenomena without exception, from the motions of the heavenly bodies and the fall of a rolling stone to the growth of plants and the consciousness of men, obey one and the same great law of causation; that all may be ultimately referred to the mechanics of atoms—the mechanical or mechanistic, homogeneous or monistic view of the universe; in one word, Monism.

II. The doctrine of derivation, or theory of descent, as a comprehensive theory of the natural origin of all organisms, assumes that all compound organisms are derived from simple ones, all many-celled animals and plants from single-celled ones, and these last from quite simple primary organisms—from monads. As we see the organic species, the multiform varieties of animals and plants, vary under our eyes through adaptation, while the similarity of their internal structure is reasonably explicable only by inheritance from common parent-forms, we are forced to assume common parent-forms for at least the great main divisions of the animal and vegetable kingdoms, and for the classes, orders, and so forth. Thus the number of these will be very limited, and the primitive archigonian parent-forms can be nothing else than monads. Whether we finally assume a single common parent-form (the monophyletic hypothesis), or several (the polyphyletic hypothesis), is wholly immaterial to the essence of the theory of descent; and it is equally immaterial to its fundamental idea what mechanical causes are assumed for the transformation of the varieties. This assumption of a transformation or metamorphosis of species is, however, indispensable, and the theory of descent is very properly called also the "metamorphosis hypothesis," or "doctrine of transmutation;" as well as Lamarckism, after Jean Lamarck, who first founded it in 1809.

III. The doctrine of elimination, or the selection theory, as the doctrine especially of "choice of breed or selection," assumes that almost all, or at any rate most, organic species have originated by a process of selection; the artificial varieties under conditions of domestication—as the races of domestic animals and cultivated plants—through artificial choice of breeds; and the natural varieties of animals and plants in their wild state by natural choice of breeds: in the first case, the will of man effects the selection to suit a purpose; in the second, it is effected in a purposeless way by the "struggle for existence." In both cases the transformation of the organic forms takes place through the reciprocal action of the laws of inheritance and of adaptation; in both cases it depends on the survival or selection of the better-qualified minority. This theory of elimination was first clearly recognised and appreciated in its full significance by Charles Darwin in 1859, and the selection-hypothesis which he founded on it is