470 THE STRUCTURE OF EVOLUTIONARY THEORY
that the earth's geological history proceed in a particular way: for the stage of
environmental change must permit the Darwinian play to operate (and dominate) in
our real world. Even the most logical and brilliant theory can do no explanatory
work if surrounding conditions never permit its results to emerge. (The expansion
of H 2 O upon freezing may be both true and abstractly important, but irrelevant on a
hot planet that has never experienced a temperature approaching 0° C.)
Darwin himself may not have felt the press or worry of this added
commitment to a Lyellian earth, for his belief in such a world had deep roots, well
antedating his formulation of natural selection (see his first three geological books
on coral reefs, volcanic islands, and the geology of South America— 1842, 1844,
and 1846). Still, the conceptual constraint of requiring an external license for an
internally consistent mechanism has operated as a distinctive and problematical
claim throughout the history of Darwinism. I shall, in this chapter, first explicate
Darwin's argument about biotic competition and progress, then discuss the required
geological license more directly, summarize the strengths and character of the
unfairly maligned catastrophist alternative, and suggest how an alteration of the
geological stage might modify or expand the tenets of Darwinism.
THE PREDOMINANCE OF BIOTIC COMPETITION
AND ITS SEQUELAE
We all know that the most vulgar misinterpretation of Darwin, often willfully made
for martial ends, holds that "survival of the fittest" mandates the subjugation and
extermination of people and nations considered inferior. We also know the
conventional and proper response to this harmful distortion: Darwin conceived
"struggle" as a metaphorical concept defined in terms of reproductive success, not
bloody battle. We can all cite the famous and standard quotation: "I should premise
that I use the term Struggle for Existence in a large and metaphorical sense,
including dependence of one being on another, and including (which is more
important) not only the life of the individual, but success in leaving progeny. Two
canine animals in a time of dearth may be truly said to struggle with each other,
which shall get food and live. But a plant on the edge of a desert is said to struggle
for life against the drought, though more properly it should be said to be dependent
upon the moisture" (1859, p. 62).
Still, the link of struggle with overt battle does play a crucial role in Darwin's
thought. He did include both biotic competition (the domain of overt battle) and
prevalence in difficult environments (the plant at the edge of a desert) within his
larger concept of struggle. And he did regard all forms of biotic competition,
including symbiosis and symbolic posturing for success in mating—not only
combat leading to death or injury—as modes of struggle. Nonetheless, by strongly
emphasizing biotic over abiotic competition, and by stressing examples leading to
the death of losers, Darwin did favor the close analogs of battle. Thus, his friend
and supporter T. H. Huxley frequently referred