Linnaeus' biological theory of the fixity of the species is so superbly suited to serve as the point of departure for our investigations because of its persuasive simplicity. In a few lucid sentences the fixity of the living type is exhaustively formulated, and at the same time a catalogue of problems is presented that would be desirable in race theory today, since the modern studies are caught up in the difficulties of one or another subordinate detail and thus lose sight of the whole.
In his "Observationes" in Regna III Naturae, Linnaeus developed in a series of propositions the axioms of biology as he practiced it; and the first four of these propositions formulate the problem of species.
The first proposition states the fact that all living beings emerge from an egg and that each egg produces a creature that resembles its parents. Linnaeus concludes from this that no new species are produced in the present time.
The second proposition speaks of the multiplication of the number of individuals in all species through ongoing procreation; and from this he concludes that each species consists of a greater number of individuals today than it did in the beginning.
In the third proposition Linnaeus traces this multiplied chain back to the original ancestor of each species (either a hermaphrodite or a pair differing in gender).
The fourth proposition infers that since, first, no new species can emerge, and, second, like produces only like, and, third, the species is a unity—therefore the origin of those creative unities must be traced back to God.
Thus the species are ontic unities and cannot vary; procreation is nothing more than the method for preserving these unities through the generations; the originator of these unities is God. The concepts and theses are forcefully and clearly formulated, and some of them are still part of the edifice of race theory in their original primitiveness. Thus the thesis of the immutability of hereditary unities is preserved in the principle of the constancy of racial types; it is the indispensable basis for the claim of the fateful consequences for man's spiritual and intellectual life that result from his belonging physically to a particular race.
Through a strange concatenation of historical circumstances, in the prevailing popular opinion [Nazi race ideology in 1933], the concept of the species and subspecies, after having gone through natural philosophy, Darwinism, and recent research in genetics, has once again arrived at the point where it was in Linnaeus' time. And the new attempts to interpret the phenomena of constancy and variation in such a way that the insight into the creative power of nature regains its rightful place have not progressed to the point where we would be justified in speaking of a new post-Linnaean view of the living world.
What remains overlooked today is the problem of origins in this context. Linnaeus solved it with his thesis that God has created the life form and fixed it for all time, but since God as the originator of species and races is out of the question for any self-respecting modern scholar, these living unities must have "evolved." [This] brings up the phenomenon of variation, which cannot be reconciled with the claim of strict constancy.
[Finally it is not taken into consideration that] nothing is gained with the word evolution and that the beginning or origin of a succession of phenomena of the type of the living form is (1) a theoretical and speculative problem and (2) a metaphysical, real-ontological problem; at most, this is grudgingly admitted for the problem of the absolute origin of being.