The Essence of Darwinism and the Basis of Modern Orthodoxy 109
almost frenetic pace in its cascading of facts, one upon the other. Only Darwin's
meticulous sense of order and logic of argument save the work from disabling
elision and overload.
Whenever he introduces a major subject, Darwin fires a volley of disparate
facts, all related to the argument at hand—usually the claim that a particular
phenomenon originated as a product of history. This style of organization virtually
guarantees that Whewell's "consilience of inductions" must become the standard
method of the Origin. Darwin's greatest intellectual strength lay in his ability to
forge connections and perceive webs of implication (that more conventional
thinking in linear order might miss). When Darwin could not cite direct evidence
for actual stages in an evolutionary sequence, he relied upon consilience—and
sunk enough roots in enough directions to provide adequate support for a single
sturdy trunk of explanation.
Again, Darwin starts with pigeons, unleashing a cannonade of disparate
arguments, all pointing to the conclusion that modern breeds of pigeons derive
from a single ancestral stock. None of these facts permits the construction of an
actual temporal series (methods one and two); but all identify the features of a
current configuration that point to history as the underlying cause. Darwin, as
usual, proceeds by particular example, but I doubt that a better general description
of consilience could be formulated:
From these several reasons, namely, the improbability of man having
formerly got seven or eight supposed species of pigeons to breed freely
under domestication; these supposed species being quite unknown in a wild
state, and their becoming nowhere feral; these species having very
abnormal characters in certain respects, as compared with all other
Columbidae, though so like in most other respects to the rock pigeon; the
blue color and various marks occasionally appearing in all the breeds, both
when kept pure and when crossed; the mongrel offspring being perfectly
fertile;—from these several reasons, taken together, I can feel no doubt that
all our domestic breeds have descended from the Columba livia with its
geographical subspecies (pp. 26-27).
Every scholar could cite a favorite case of Darwinian consilience. For my
part, I especially admire Darwin's uncharacteristically long discussion (pp. 388-
406) on transport from continental sources and subsequent evolution to explain the
biotas of oceanic islands. Consider the main items in Darwin's own order of
presentation:
(1) The general paucity of endemic species on islands, contrasted with
comparable areas of continents; why should God put fewer species on islands?
(2) The frequent displacement of endemic island biotas by continental species
introduced by human transport. If God created species for islands, why should
species designed for continents so often prove superior in competition: "He who
admits the doctrine of the creation of each separate species, will have to admit, that
a sufficient number of the best adapted plants and animals have not been created
on oceanic islands; for man has unintentionally stocked them from various sources
far more fully and perfectly than has nature" (p. 390).