A Division of Worms

Natural History, Feb, 1999 by Stephen Jay Gould

   In sketching the life of one of our most celebrated naturalists, we have
   conceived it to be our duty, while bestowing the commendation they deserve
   on the great and useful works which science owes to him, likewise to give
   prominence to such of his productions in which too great indulgence of a
   lively imagination had led to results of a more questionable kind, and to
   indicate, as far as we can, the cause or, if it may be so expressed, the
   genealogy of his deviations.

Cuvier then proceeded to downplay Lamarck's considerable contributions to anatomy and taxonomy and to excoriate his senior colleague for fatuous speculation about the comprehensive nature of reality. Cuvier especially ridiculed his subject by contrasting his caricature of Lamarck's ideas with the sober approach of proper empiricism:

   These [evolutionary] principles once admitted, it will easily be perceived
   that nothing is wanting but time and circumstances to enable a monad or a
   polypus gradually and indifferently to transform themselves into a frog, a
   stork, or an elephant.... A system established on such foundations may
   amuse the imagination of a poet; a metaphysician may derive from it an
   entirely new series of systems; but it cannot for a moment bear the
   examination of anyone who has dissected a hand ... or even a father.

Cuvier's eloge reeks of exaggeration and unjust ridicule, especially toward a colleague ineluctably denied the right of response--the reason, after all, for our venerable motto De mortuis nil nisi bonum (Say only good of the dead). But Cuvier did base his disdain on a legitimate substrate, for Lamarck's writing certainly shows a tendency to grandiosity in its comprehensive pronouncements, combined with frequent refusal to honor, or even to consider, alternative views with strong empirical support.

L'esprit de systeme, the propensity for constructing complete and overarching explanations based on general and exceptionless principles, may apply to some corners of reality but works especially poorly in the maximally complex world of natural history. Lamarck did feel drawn to this style of system building, and he showed no eagerness to acknowledge exceptions or to change his guiding precepts. But the rigid and dogmatic Lamarck of Cuvier's caricature can be regarded only as a great injustice, for the man himself did maintain appropriate flexibility before nature's richness and did eventually alter the central premises of his theory when his own data on the anatomy of invertebrate animals could no longer sustain his original view.

This fundamental change--from a linear to a branching system of classification for the basic groups, or phyla, of animals--has been well documented in standard sources of modern scholarship about Lamarck (principally in Richard W. Burkhardt Jr.'s The Spirit of System: Lamarck and Evolutionary Biology, Harvard University Press, 1977; and Pietro Corsi's The Age of Lamarck: Evolutionary Theories in France 1790-1830, University of California Press, 1988). But the story of Lamarck's intellectual journey remains incomplete, for both the first explicit statement and the final conclusion have been missing from the record--the beginning because Lamarck noted his first insight as a handwritten insertion, heretofore unpublished, in his own copy of his first printed statement about evolution (the Floreal address of 1800, recycled as the preface to his 1801 book on invertebrate anatomy); and the ending because his final book of 1820, Systeme analytique des connaissances positives de l'homme (Analytic system of positive knowledge of man), has been viewed only as an obscure swan song about psychology--a rare book even more rarely consulted, despite a fascinating section containing a crucial and novel wrinkle on Lamarck's continually changing views about the classification of animals. Stories deprived of both beginnings and endings cannot satisfy our urges for fullness or completion--and I am grateful for this opportunity to supply these terminal anchors in this two-part essay.