122 THE STRUCTURE OF EVOLUTIONARY THEORY
The origin of Darwin's concept of natural selection provides my favorite example
of cultural context as a promoter.
The link of Darwin to Malthus has been recognized and accorded proper
importance from the start, if only because Darwin himself had explicitly noted and
honored this impetus. But if Darwin required Malthus to grasp the central role of
continuous and severe struggle for existence, then he needed the related school of
Scottish economists—the laissez-faire theorists, centered on Adam Smith and the
Wealth of Nations (first published in the auspicious revolutionary year of 1776)—
to formulate the even more fundamental principle of natural selection itself. But
the impact of Adam Smith's economics did not strike Darwin with the force of
eureka; the concepts crept upon him in the conventional fashion of most influences
upon our lives. How many of us can specify a definite parental admonition, or a
particular taunt of our peers, as central to the construction of our deepest
convictions?
Silvan S. Schweber (1977), a physicist and historian of science, has traced the
chain of influence upon Darwin from Adam Smith's school of Scottish
economists—beginning in the early 1830's, and culminating in Darwin's intense
study of these ideas as he tried to fathom the role of individual action during the
weeks just preceding his "Malthusian" insight of September 1838. I believe that
Schweber has found the key to the logic of natural selection and its appeal for
Darwin in the dual role of portraying everyday and palpable events as the stuff of
all evolution (the methodological pole), and in overturning Paley's comfortable
world by invoking the most radical of possible arguments (the philosophical pole).
In fact, I would advance the even stronger claim that the theory of natural
selection is, in essence, Adam Smith's economics transferred to nature. We must
also note the delicious (and almost malicious) irony residing in such an assertion.
Human beings are moral agents and we cannot abide the hecatomb*—the death
through competition of nearly all participants—incurred by allowing individual
competition to work in the untrammeled manner of pure laissez-faire. Thus, Adam
Smith's economics doesn't work in economics. But nature need not operate by the
norms of human morality. If the adaptation of one requires the deaths of thousands
in amoral nature, then so be it. The process may be messy and wasteful, but nature
enjoys time in abundance, and maximal efficiency need not mark her ways. (In one
of his most famous letters, Darwin wrote to Joseph Hooker in 1856: "What a book
a devil's chaplain might write on the clumsy, wasteful, blundering, low, and
horribly cruel works of nature!") The analog of pure laissez-faire can and does
operate in nature—and Adam Smith's mechanism therefore enjoys its
* "Hecatomb," an unfamiliar word in English, should enter the vocabulary of
all evolutionists as a wonderfully appropriate description for this key aspect of
Darwinism. A hecatomb is, literally, an offering of a hundred oxen in
sacrifice. Yet, even in Homer, the word had come to designate any large
number of deaths incurred as a sacrifice for some intended benefit—a good
description of natural selection. And hecatomb trips so much more lightly off
the tongue than "substitutional load."