442 THE STRUCTURE OF EVOLUTIONARY THEORY
- Darwin recognized both kinds of variation. Early in his career he correctly
emphasized the mutational mode. Unfortunately, his critics later badgered him into
a more extreme and less generous commitment to the primacy of fluctuating
variation (note the direct contradiction to claim 4 and, in turn, the contradiction of
4 and 1—quite an intellectual odyssey: from exclusivity of one form, to pluralism,
to exclusivity of the other. Note also that de Vries often stated all these positions in
the same publication; thus, I am not only recording a consistent and legitimate
ontogenetic change in opinion): "To sum up, we see that Darwin always
distinguished between individual differences and single variations and that he
ascribed to the latter at least a very considerable role in the origin of species. It was
only by the pressure of criticism that he finally gave up this view and gave the
place of honor to the ever-present individual variations" (1909a, volume 1, p. 39). - Darwin erred in advocating natural selection for the origin of species. The
Mutation Theory has corrected this basic mistake, and therefore represents a novel
direction for evolutionary thought. Darwin deserves our highest praise for his
historical role, but he has now been superseded:
The theory of descent aims at the scientific explanation of systematic
relationship. It is Darwin's immortal service to have obtained general
recognition for this generalization. By doing this he revolutionized the
whole of biological, systematic, embryological and paleontological science.
Tapping inexhaustible sources for new investigation and discovering
everywhere mines where new facts were to be had for the picking up. The
several propositions and hypotheses which Darwin employed as supports
for this theory should be regarded now only as such, since their interest is
mainly historical. They have served their purpose and are thereby fully
justified... This is especially true of the theory of selection, which now has
served its time as an argument for the theory of descent; happily this theory
no longer stands in need of such support (1909a, volume 1, p. 28).- The theory of natural selection is erroneous. The theory of mutation is
correct. "The mutation theory is opposed to that conception of the theory of
selection which is now prevalent. According to the latter view the material for the
origin of new species is afforded by ordinary or so-called individual variation.
According to the mutation theory individual variation has nothing to do with the
origin of species. This form of variation, as I hope to show, cannot even by the
most rigid and sustained selection lead to a genuine overstepping of the limits of
the species and still less to the origin of new and constant characters" (1909a,
volume 1, p. 4).
One might conjecture that this full range of viewpoints represents a transition
from heart (in the early entries of the sequence) to mind—that is, from de Vries'
need to express fealty with his personal hero to his recognition of the oppositional
logic within his own system. (One might also be more cynical and interpret the
early entries as diplomatic attempts to court favor with Darwinians—but I don't
think that this interpretation can be fairly defended, for