124 THE STRUCTURE OF EVOLUTIONARY THEORY
work. Moreover, this cause operates at a lower level, and solely for the benefit of
individual firms. Only as an incidental result, a side-consequence, does good
design and overall balance emerge. Adam Smith, in coining one of the most
memorable metaphors in our language, ascribed this process to the action of an
"invisible hand." In the modern terms of hierarchy theory, we might say that
overall order arises as an effect of upward causation from individual struggle. We
may thus gain some clarity in definition, but we can't match the original prose. In
his most famous words, Smith wrote in the Wealth of Nations (Book 4, Chapter 2):
"He intends only his own gain, and he is in this, as in many other cases, led by an
invisible hand to promote an end which was no part of his intention ... I have never
known much good done by those who affected to trade for the public good."
But Paley had assured us, in 500 closely-argued pages, that the analogous
features of the natural world—good design of organisms and harmony of
ecosystems—not only prove the existence of God, but also illustrate his nature, his
personality, and his benevolence. In Darwin's importation of Adam Smith's
argument, these features of nature become epiphenomena only, with no direct
cause at all. The very observations that Paley had revered as the most glorious
handiwork of God, the unquestionable proof of his benevolent concern, "just
happen" as a consequence of causes operating at a lower level among struggling
individuals. And, as the cruelest twist of all, this lower-level cause of pattern seems
to suggest a moral reading exactly opposite to Paley's lofty hopes for the meaning
of comprehensive order—for nature's individuals struggle for their own personal
benefit, and nothing else! Paley's observations could not be faulted—organisms are
well designed and ecosystems are harmonious. But his interpretations could not
have been more askew— for these features do not arise as direct products of divine
benevolence, but only as epiphenomena of an opposite process both in level of
action and intent of outcome: individuals struggling for themselves alone.
I write this chapter with two aims in mind: first, to explicate the major sources
and content of Darwin's argument; and second, to identify the truly essential claims
of Darwinism, in order to separate them from a larger set of more peripheral
assertions and misunderstandings—so that we can rank and evaluate the role of
modern proposals and debates by the depth of their challenge to the central logic of
our profession's orthodoxy. To fulfill this second goal, I try to identify a set of
minimal commitments required of those who would call themselves "Darwinians."
I argue that this minimal account features a set of three broad claims and their
(quite extensive) corollaries. I then use this framework to organize the rest of this
book, for I devote the historical chapters of this first part to pre- and post-
Darwinian discussions of the three claims. Then, following a chapter on the
construction of the Modern Synthesis as a Darwinian orthodoxy for the twentieth
century, I revisit the three claims in the second part, this time by examining
modern challenges to their exclusive sway.
By interpreting Darwin's radical theory as a response to Paley (actually an
inversion), based on an importation of the central argument from Adam