486 THE STRUCTURE OF EVOLUTIONARY THEORY
and interpolation; the catastrophists preached empirical literalism! (I do not raise
this issue to denigrate Lyell and Darwin, for I support their procedure as a general
statement about scientific methodology. Slavish literalism should be shunned in
general, and not only (as in this geological case) when we have reason to regard a
preserved record as systematically imperfect. Still, I know no greater irony in the
history of science than the inverted posthumous reputations awarded to Lyell and
the catastrophists for their supposed positions on "objectivism" in science.)
In paleontology, catastrophism reached an apogee in Georges Cuvier's
Discours preliminaire, originally written as a preface to his great four-volume
compendium on fossil vertebrates (Recherches sur les ossemens fossiles, 1812),
but published and republished separately as an "Essay on the theory of the earth."
Cuvier did not present his Essay as a textbook of catastrophism, but as a statement
about the roles that paleontology and geology should play in unravelling the
history of the earth. Nonetheless, Cuvier's Essay exposes all characteristic features
of catastrophism as a science, and illustrates the incompatibility of this geological
approach with Darwin's prerequisites for natural selection as a chief agent of
macroevolutionary pattern.
On the substantive side of catastrophism, Cuvier devoted most attention to
demonstrating life's temporal directionality, and to illustrating the value of such a
vector for inferring geological history and stratigraphic order. As his greatest
contribution, Cuvier proved that species could become extinct (a phenomenon still
widely doubted at the inception of the 19th century). In his major source of
evidence, Cuvier demonstrated that the anatomy of some fossil quadrupeds lay
outside the boundaries of variation within modern species. He also traced a
stratigraphic sequence of increasing similarity to modern faunas in successively
younger beds, thus documenting a directional pattern within sequences of
extinction, and providing the earth with a meaningful history. Cuvier begins the
Essay by castigating his predecessors for combining their grandiose speculative
theorizing with an inattention to fossils and their stratigraphic positions. He then
presents his concept of proper procedure in the form of a list of questions, mostly
centered upon historical pattern and direction in stratigraphy. "Are there certain
animals and plants peculiar to certain strata, and not found in others? What are the
species that appear first in order, and those, which succeed? Do these two kinds of
species ever accompany one another? Are there alterations* in their appearances;
or, in other words, does the first species appear a second time, and does the second
species then disappear?" (1818, p. 65).
Cuvier's answer, leading to the birth of modern paleontology, affirms
directionality in two senses: fossils from successively older strata become
increasingly
- Cuvier's original text reads: "Y a-t-il des alternatives dans leur retour," so
"alterations," in Jameson's standard translation, should probably read "alternations," thus
rendering Cuvier's inquiry as a question about directionality. He wants to know whether
fossil species mark unique episodes of time, a proposition that would be disproved if
faunas appeared and reappeared in alternation.