I recently became aware that the probable originator of the “biological” species concept, which I prefer to call the Reproductive Isolation Species Conception*, or RISC, was Johann Friedrich Blumenbach (1752–1840). He presented this in his doctoral thesis On the natural varieties of mankind (1776), and I missed putting it in my book. What I was not aware of is that Blumenbach wrote a number of books, which were in fact readily translated into English, and one, A manual of the elements of natural history (1825) was widely read, including, as we know, by Darwin when he was still trying to set forth his then sketchy ideas on evolution.
Blumenbach’s Manual is a curious text. It is largely philosophical in the sense that he is trying to set forth a scheme of ideas and general principles that make sense of what was known in biology at the time (1782 for the first edition of the Handbuch der Naturgeschichte). In one way it is an early philosophy of biology. But he makes a number of factual claims, such as his widely cited (but, I fear, badly misunderstood) notion of Bildungstrieb, often translated in English as “formative impulse” or “vital power”.
This is a vague notion of what we might think of as the “generative capacity” of organic bodies; a kind of mix of both heredity and development. Blumenbach is throwing his hat in with those we call epigenesis advocates, in which there are inborn propensities to develop organisms rather than inbuilt structures that merely need to grow, as the preformationists held.† Although he and Kant are regarded as agreeing mostly on this power, they in fact fell out over it (Richard 2000). But Blumenbach does not load the notion with any great weight:
I trust that it is unnecessary to remind the greater part of my readers, that the term Formative Impulse, like the names of every other vital power, of itself, explains nothing; it merely serves to designate a peculiar power formed by the combination of the mechanical principle with that which is susceptible of modification; a power, the constant agency of which we ascertain by experience, whilst its cause, like that of all other generally recognized natural powers, still remains, in the strictest sense of the word—”qualitas occulta*.” [p12]
The asterisk is a reference to Voltaire using the same Latin term for hidden qualities. In other words, Blumenbach knows this is, as it were, something that we recognize in general terms by experience only, and which we hope we will one day have some theoretical explanation for. It’s like the dormitive virtue of opium in Moliére’s The Imaginary Invalid (1673). Having such a concept is intended to guide further thinking, and in a way, it did.
He has a distinction between varieties and monsters, such that when the formative impulse is acted upon in a normal manner, it gives rise to the former, but when it is acted on abnormally, you have disease and “monsters”. For students of hybridisation, note that he allows for hybrids (he calls them Bastards). The discussion on Monsters is an attempt to set up a taxonomy of abnormal development.
What is also of interest in hindsight, knowing that Darwin read this book, is how it treats evolution. In fact, Blumenbach refers to the “hypothesis of evolution”, some 70 years before the Origin. As Gould noted the term meant for Albrecht Haller (1708–1777), who coined it in 1744, basically at the grand scale what it meant in the individual life of the organism: development, an unrolling of a potential already there. The “hypothesis of evolution” was that the potential for all living beings was in the soil of the world in potentia and time would see its inevitable rollout. For Blumenbach, he has this to say:
In order to explain the formation of organized bodies, the hyqpothesis of evolution has been advanced, particularly in modem times. According to it, neither human beings, nor other animals, nor plants are generated, but all have existed from the first creation as perfect, pre-formed germs, within their ancestors, the succeeding generations being lodged in the preceding ones like nests of boxes, and progressively developed, and brought to light by the process of impregnation; an idea which, even if it were not most decisively contradicted by the results of experience, must be considered as inconsonant with every principle of unbiassed reason, as well from the interposition of preternatural (hyper-physical) arrangements which it renders necessary, as from (contrary to all the rules of the philosophical study of Nature,) the uncalled for multiplication of natural (physical) powers, and from the incalculable number of creations without any object, consisting in the multitude of preformed germs, which can never have even an opportunity of development. [pp8–9]
So clearly what Blumenbach is arguing against (now, for he was when younger he was an advocate of the Haller evolution hypothesis) is not the modern theory of evolution at all (see Lenoir 1980); and the view that travels under the term must have influenced Darwin in his attempt to avoid the term altogether. But he was foiled: Spencer had used the term in his pre-Origin book, and all reviewers as well insisted on using the term. And as a result, we have a mixed and mashed view of evolution as having missing links, progressive series, and being the unfolding of potential, all contrary to Darwin’s conception.
Oddly, and somewhat ironically, Blumenbach’s Bildungstrieb has something of a renaissance these days, both (again ironically) under the name epigenetics (see note), and as the so-called “interactionist consensus” of modern biology, in which phenotypes are developmental outcomes in a specific environment. Sometimes, to know the place for the first time, you have to come around full circle on your journey.
References and notes
Lenoir, Timothy. 1980. Kant, Blumenbach, and Vital Materialism in German Biology. Isis 71 (1):77-108.
Richards, Robert J. 2000. Kant and Blumenbach on the Bildungstrieb: A Historical Misunderstanding. Stud. Hist. Phil. Biol. & Biomed. Sci 31 (1):11–32.
* I say “conception” because it is a particular understanding of a concept – species. To talk about species concepts in the plural is to prejudice the argument that one conception is the only appropriate one (and of course that is the one of the person talking about the offered views, usually Mayr).
† One might say that modern gene centrism is a kind of preformationism, leading to a misunderstanding of the nature and role of genes. Unfortunately, modern epigenetics is about something other than propensities to develop in a particular manner, although some have redefined it that way, more in line with Conrad Waddington’s meaning when he introduced it in 1942.