Internalism and Laws of Form 279
of origin—that is, we must still know whether an ancestral form arose by
adaptation or constraint (or by what mixture of the two poles). Thus, we may say
that Darwin's new dimension expanded the scope of the dichotomy by compelling
its application to two domains—past and present—when we analyze the basis of
any trait in a living organism.
Evolution does not establish an ultimate divide for all transitions in the history
of biology. Several themes pass right through this great revision, only altering their
terms and explanations. Formalism vs. functionalism may be the most prominent
and persistent of issues too grand even for evolution to undo (or fully resolve).
Paley and Agassiz once fought this battle in grand style; Dawkins and Goodwin
cannot cast so broad a conceptual net, or muster the same stylistic panache today,
but they pursue the same conflict. Paley vs. Agassiz remains relevant to modern
evolutionists by the primary criterion of genealogical continuity.
If Paley and Agassiz represent the yin and yang of totality for the analysis of
form, then Darwin, though a pluralist who understood both poles, did ultimately
cast his lot with the Paleyan yin, in filial piety with a British tradition that has
spanned centuries, and still continues today. This imbalance, and the struggle for
redress that now commands so much discussion in contemporary evolutionary
biology, defines one of the three major issues that led me to write this book. The
formalist alternative, as embodied in the subject now generally called "constraint,"
provides a counterweight to stabilize the second leg in Darwin's essential tripod of
support—the primacy of adaptation in asserting the creativity of natural selection
at overwhelming relative frequency among the causes of evolutionary change.
The past holds sufficient interest and capacity for illumination all by itself,
and no justification in terms of present enlightenment need ever be given. Still, as a
practicing scientist, I do favor the use of history as a current guide— while I
struggle not to wrench the meaning and motivation of arguments from the primary
matrix of their own time. I don't know how else to proceed when tides of history
overwhelm a worthy subject for little reason beyond the vagaries of fashion and
contingency. Scientists too often become convinced that inexorable logic or
irrefutable data have closed a subject forever. Even worse, given our propensity for
historical ignorance, we often collectively forget that an alternative ever existed at
all. In such cases, I know no better tactic for reopening an important subject than
the record of history—the proof that brilliant scientists (so worthy of our
admiration that we cannot belittle their concerns) devoted their concentrated
attention to an issue that never achieved true settlement, but only veered towards
transient "resolution" by sociological complexities of shifting preferences, rather
than logic of proof or exigencies of data. I believe that structuralist and formalist
approaches to anatomy fell out of favor for such invalid reasons of fashion, and
that the full range of this primary dichotomy must now be reestablished. And I
unabashedly call upon the great formalists of history to state their case; while I ask
modern evolutionists to make the proper translation to modern terms.