DANIEL BROWNaccount suggests, and that its geological formations can be explained
without recourse to such divine interventions as the Great Flood.
Tennyson describes astronomy and geology in his late poem "Parnassus"
(1889) as "terrible Muses" (AT 16). Both sciences had been formidable
sources of inspiration from an early point in his career. His wide reading
acquainted him with P.S. Laplace's nebular hypothesis that had by 1800
eliminated the need to invoke God to explain the origin and regular
movements of the planets. Laplace argued that the planets orbited in the
same plane and the same direction because they had been formed together,
in accordance with the laws of physics and chemistry, as the condensation
of the sun's revolving gaseous atmosphere. Tennyson alludes to the theory
in section CXVIII of In Memoriam: "The solid earth wheron we tread / In
tracts of fluent heat began" (8-9). Laplace's nebular hypothesis was
complemented by the speculations of G.L.L. Buffon and Jean-Baptiste
Lamarck on the mutability of species. Lyell's Principles was probably the
main source for Tennyson's early familiarity with Lamarck's doctrines of
evolution, in which an animal's continuous use of specific attributes ensures
that certain physical features become more prominent. Lamarck believed
that such changes were heritable, so that in his famous example of the
giraffe, the neck and front legs of the creature enlarged over time as each
generation strove for edible leaves that lay beyond their reach.
The nebular hypothesis, the evidence of the fossil record, and La-
marckian models of species development: all are synthesized in the spec-
ulative evolutionary cosmology that Robert Chambers presented
anonymously in his popular Vestiges of the Natural History of Creation
(1844). Tennyson read a review of the book in November 1844 that
prompted him to remark: "it seems to contain many speculations with
which I have been familiar for years." 7 Section CXVIII presents a progres-
sive evolutionary history that echoes the broad sweep of Chambers's
cosmology. Beginning with Laplacian and Lyellian principles of "fluent
heat" and "cyclic storms" (n), the stanzas advance to the appearance of
humanity and its possible future evolution. At this point, Tennyson appeals
to a Lamarckian principle in which human beings strive to purge them-
selves of their animal inheritance, so that they can "Move upward, working
out the beast" (27). But it is noticeable that Tennyson opens the long
sentence that features these ideas with the conditional phrase "They say"
(7). The skeptical inflection of this phrase emerges more clearly in section
CXX, where the poet feels able to dismiss materialist science, even if it
should finally establish that human beings are nothing more than "cunning
casts in clay": "Let Science prove we are, and then / What matters Science
unto men, / At least to me?" (5-8). This is the strongest of Tennyson's
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