Species

Historical Summary and Conclusions 271

species, which relied upon the Great Chain conception. There was disagreement
about the level of organization, too. Buffon thought that local forms were variants of
the true species, the premiere souche, while Linnaeans tended to name any persistent
variant form as a species. Bonnet and the early Buffon thought that specic forms
were mere abstractions, a nominalist view that gradation imposed also on Lamarck.
Even so, all these writers made use of a generative conception. Species may not exist,
but if they did they were the result of heredity on the reproduction of forms.
Species realists in the later biological tradition tended to be xists, such as Cuvier
and Agassiz, but of course such a contrast was not possible until the possibility of
transmutation over time was mooted. In the period before xism was introduced,
typology was widespread, but species were at best only mutable, not transmutable,
excepting the case of spontaneous generation, in which species could sequentially
change in outward form, rather like the metamorphosis of insects. The process by
which species came to be in the rst instance, however, was irrelevant to how they
were maintained, and a generative notion was used by realists as well, especially
those who stressed form as an identifying or diagnostic factor. Most of them differed
from the transmutationists as to whether the formal diagnosis was a mark of the
real essence; xists thought that the generative process was the reason for the form,
transmutationists that the generative process (Lamarck’s feu éthéré, for example)
was the reason only for the form in a given time or place or conditions. In short, for
xists, the form gave the essence, while for transmutationists, the “essence” meant
that the form would not remain constant. Some like Buffon and A.-P. de Candolle
bridged the two camps, and declared that the real essence of a species was modied
to a certain degree by local conditions and hybridization.
In the period before the Origin, in Britain and presumably elsewhere, species
were declared to be the “property,” as it were, of competent and recognized tax-
onomists, particularly in museums, as McOuat has discussed. A number of experts
doubted the permanence of species so that by the mid-century, several writers had
made the suggestion in reputable forums that species did change.
Darwin’s own views changed—at rst, he was quite comfortable with the stan-
dard generative notion, and made notes on the idea that it was either the physical
impossibility of interbreeding or the “repugnance” of species to interbreed in the
wild. Diagnostic issues followed from the facts of the matter (the nominal essence
did not give the real essence, in other words). But early on he started to toy with the
notion that species were meaningless and conventional, and at the time of the Origin
and shortly after, he seems to have taken this as his position—species are the out-
comes of the evolutionary process acting on varieties, and although real entities indi-
vidually, the rank of species is not real. It doesn’t seem to have made much impact
on his own systematic practice, as it was not to have made much impact on anyone
else either, for some time to come. The rank of species is arbitrary in the Origin.
However, species could “do” things—they could even compete with each other.
Darwin rst thought that geographical isolation formed species most of the time
but by the Origin had shifted to the view that selection against intermediates and
hybrids was the major force. The geographic view of speciation, though, was to
become the majority position in opposition to Darwin except for a few of his most
devoted followers. However, while he may have been a conventionalist in his view