134 THE STRUCTURE OF EVOLUTIONARY THEORY
will certainly give an immense advantage to one tribe over another" (1871, p. 166).
This passage has often been quoted, but without its surrounding context of
contrary alternatives and restrictive caveats, as a clean example of Darwin's move
to a higher level of selection when required. But such an interpretation seriously
misrepresents Darwin's motives and logic. He did make the move, but only as one
factor in a surrounding context of mitigation. I regard these mitigations and
restrictions to hold the line of organismal selection (expressed in three distinct
arguments, discussed below) as far more interesting than the move itself, for
Darwin's extreme reluctance to address selection at any level other than the
organismic lies so well exposed in the totality.
- The Descent, as a whole, rests upon the strongest mode of argument for
organismal selection. Darwin did not write a separate book on human evolution;
his ideas (mostly speculative) on this subject occupy the first, and shorter, part of a
two volume treatise entitled, in full: The Descent of Man, and Selection in Relation
to Sex. In other words, Darwin wrote the Descent as an introduction to his general
exposition of sexual selection. We might regard the two parts as oddly juxtaposed
until we realize that many of Darwin's major arguments about human evolution—
in the establishment of secondary sexual characters, and in differentiation among
races, for example—invoke sexual selection by intraspecific competition, rather
than ordinary natural selection as adaptation to external environments. As Ruse
(1980) notes, Darwin viewed sexual selection as the strongest general argument
against group selection, for its theme of relentless struggle in mating among
members of a population guarantees that individualism must reign, largely by
precluding the formation of alliances that higher-level selection could exploit.
(Modern notions of sexual selection do envision the formation of such alliances, so
the argument may strike us as incorrect today—but Darwin conceived sexual
selection as a hyperindividual mode.) - Darwin does not present his argument for tribal selection as a happy
solution to the problem of morality, but only as one potential factor among others.
He also devises an argument based on organismal selection—in the form that
would be called "reciprocal altruism" today: "As the reasoning powers and
foresight of the members became improved, each man would soon learn from
experience that if he aided his fellow-men, he would commonly receive aid in
return. From this low motive he might acquire the habit of aiding his fellows"
(1871, p. 163). - Darwin presents tribal selection as a peculiarity based on the uniqueness of
human consciousness, and thus as a strictly circumscribed exception to the
generality of organismal selection throughout living nature. As conscious beings,
we become especially sensitive to the "praise and blame" of our fellows. If
altruistic behavior gains a status as virtuous, then we might be persuaded— against
our deeper biological drive for seeking personal advantage—to engage in such
behaviors in order to foster praise or avoid calumny. In other words, a form of
"cultural evolution," rooted in our unique level of consciousness, could overcome
the behaviors driven by organismal selection, and