304 THE STRUCTURE OF EVOLUTIONARY THEORY
Geoffroy emphasized, again and again, the two themes most calculated to rouse
Cuvier's ire, and most central to the formalist conviction that adaptation for
function can only record a secondary matching (following production by laws of
form), not a primary construction.
- Function follows form. Consider Geoffroy's favorite motto: "such is the
organ, such will be its function." Or two more specific statements from 1829
(quoted in Russell, 1916, p. 77): "Animals have no habits but those that result from
the structure of their organs ... A vegetarian regime is imposed upon the
Quadrumana by their possession of a somewhat ample stomach, and intestines of
moderate length." - Final causes cannot serve as explanatory principles. Consider Geoffroy's
second favorite motto: "Je me garde de preter a Dieu aucune intention" (I take
care not to ascribe any intentions to God).
Could Cuvier, who thought he knew God's ways (or at least the extent of His
freedoms), remain silent against the taunts of such a turbulent priest?
The debate of1830: foreplay and aftermath
Geoffroy, who loved aphorisms amidst his intense wordiness, often stated: "there
is, philosophically speaking, only a single animal." When he applied this radical
notion of archetype only within the Vertebrata (as he did in his seminal work of
1818), Cuvier remained at relative peace, albeit in opposition. But, two years later,
Geoffroy took the fatal step that first elicited overt opposition from his former
friend. Upholding formalism in explicit contrast to the functionalist credo had riled
Cuvier to a considerable extent, but so long as this apostasy did not invade the
schema of four unbridgeable embranchements, the foundation of Cuvier's
taxonomy (1817), Geoffroy could be tolerated.
In 1820, Geoffroy made a crucial move that filled him with the joy of uni-
fication, and struck Cuvier as an act of unbridled imperialism: he extended the
vertebral archetype to encompass arthropods as well, thus bringing two of the four
embranchements under a common generating form—the vertebra itself. In his key
article of 1822, Geoffroy described this "discovery" as "one
he did write on the subject (particularly in his monographs on fossil crocodiles). We might
also allow that his brand of formalism did encourage an acceptance of evolution as a possi-
bility (as Owen's approbation also testifies)—for the generation of great and continuous di-
versity (within channels) from an underlying archetype does establish a friendly climate for
transmutation (at least within Bauplan), while Cuvier's optimized functionalism discourages
any thought of evolutionary intermediacy. Evolution played a very minor role in the 1830
debate. Still, we will never understand the great antithesis of functionalism and formalism—
a subject that has pervaded the history of biology—if we misread this dichotomy in the later
light of evolutionary theory. The debate between Cuvier and Geoffroy centered upon the
primacy of form or function in morphology, hardly at all on evolution. Russell (1916, p. 66)
has neatly summarized Geoffroy's views on evolution: "That he did believe in evolution to a
limited extent is certain; that his theory of evolution was, as it were, a byproduct of his
lifework, is also certain. Geoffroy was primarily a morphologist and a seeker after the unity
hidden under the diversity of organic form. His theory of evolution had as good as no
influence on his morphology, for he did not to any extent interpret unity of plan as being due
to community of descent."