two points that I regard as most crucial to understanding the general argument
through (or despite) conscious idiosyncrasies in my presentation.
History
Many technical treatises in science begin with a short section on previous history
of work in the field—usually written in the hagiographical mode to depict prior
history as a march towards final truths revealed in the current volume. Sometimes,
authors get a bit carried away, and these historical sections expand into substantial
parts of the final book. Lest anyone make the false inference that my full first half
of history arose in this haphazard and initially unintended way, I hasten to assure
readers that my final result was my intention from the start.
For several reasons, I always conceived this book as a smooth joining of two
halves, roughly equal in length and importance. First, and ontogenetically, I had
written my earlier technical book, Ontogeny and Phylogeny, in this admittedly
unusual manner—and I remain pleased with both the distinctiveness and the
efficacy of the result. Second, I believe that the history of evolutionary thought,
and probably of any other subject imbued with such importance to our lives and to
our understanding of nature, constitutes an epic tale of fascinating, and mostly
honorable, people engaged in a great struggle to comprehend something very deep
and very difficult. Thus, such histories capture a bit of the best in us (also of the
worst, but all human endeavors so conspire)—a bit, moreover, that cannot be
expressed in any other way. We really do need to honor the temporal substrate of
our current understanding, not only as a guide to our continuing efforts, but also as
a moral obligation to our forebears.
But a third and practical reason trumps all others. Although I would not state
such a claim as a generality for all scientific analyses, in this particular case I do
not see how the structure of evolutionary theory can be resolved and the
appropriate weights of relative importance assigned to the different components
thereof, absent such a historical perspective. (Would it not be odd to claim, in any
case, that the quintessential science for resolving the nature of life's history can
itself be understood as a pristine construction, a fully-formed conceptual entity
drawn intact from some analog of Zeus's brow, rather than an "organic" structure
of ideas with its own ontogeny and history?)
To give one example at the largest and at the smallest scales of my argument,
I don't know how I could have properly defended my identification and explication
of the threefold essence of Darwinian logic without documenting the history of
theoretical debate in order to tease out the components that have always been most
troubling, most central, and most directive. A pure description of the theory's
abstract logic simply will not suffice. To epitomize, I have identified these
essential components on three basic grounds: that logic compels (Chapter 2), that
history validates (Chapters 3-7), and that current debate reaffirms (Chapters 8-12).
The middle term of this epitome unites the end members; I cannot present a
coherent or compelling defense without this linkage. The three issues of agency,
efficacy and scope build the Darwinian es-
36 THE STRUCTURE OF EVOLUTIONARY THEORY