The Fruitful Facets of Galton's Polyhedron 421
methodological premise. First, to gain broadest generality in aligning evolutionary
studies with physical sciences of higher status, de Vries opens The Mutation
Theory with a claim that theories based on discrete, atomized particles suggest
better experiments than hypotheses about continua. Moreover, such theories can
also ally biology with more prestigious fields like chemistry: "By the mutation
theory I mean the proposition that the attributes of organisms consist of distinct,
separate and independent units. These units can be associated in groups and we
find, in allied species, the same units and groups of units. Transitions, such as we
so frequently meet with in the external form, both of animals and plants, are as
completely absent between these units as they are between the molecules of the
chemist" (1909a, volume 1, p. 3). He then expressed the same argument more
strongly in a popular article (1907b, p. 17): "This principle of mutations is
conducive to the assumption of distinct units in the characters of plants and
animals. Even as chemistry has reached its present high development chiefly
through the assumption of atoms and molecules as definite units, the qualities of
which would be measurable and could be expressed in figures, in the same way
systematic botany and the allied comparative studies are in need of a basis for
measurement and calculations."
Second, and in an odd conflation of proper methodology and empirical truth-
value, de Vries argues in his Preface that Darwinian gradualism should be rejected
(or at least strongly disfavored a priori) because insensible change over millennia
cannot easily become the subject of experiment!
The origin of species has so far been the object of comparative studies only.
It is generally believed that this highly important phenomenon does not
lend itself to direct observation, and, much less, to experimental
investigation. This belief has its root in the prevalent form of the
conception of species and in the opinion that the species of animals and
plants have originated by imperceptible gradations. These changes are
indeed believed to be so slow that the life of a man is not long enough to
enable him to witness the origin of a new form. The object of the present
book is to show that species arise by saltations and that the individual
saltations are occurrences which can be observed like any other
physiological process ... In this way we may hope to realize the possibility
of elucidating, by experiment, the laws to which the origin of new species
conform (1909a, volume 1, p. vii).With such negativity towards the methodology and worldview of natural
selection and gradualism, how could Charles Darwin serve de Vries as chief
intellectual guru, even surpassing the influence of Sachs and experimental-ism?
We cannot grasp de Vries' convictions and contradictions until we understand the
powerful extent and threefold nature of Darwin's largely psychological hold upon
him.
First of all, we often forget the extent of Darwin's work on plant physiology—
largely published during the 1870's as de Vries began his career, and primarily in
the same areas, particularly the proximate causes of movement,