Charles Lyell, Historian of Time's Cycle - Time's Arrow, Time's Cycle: Myth and Metaphor in the Discovery of Geological Time - page 117

neither trait). I suggest another resolution: LyeU's dichotomy, wid- ened by
later textbook cardboard, is false outright. Geology in the 1830s was not a war
between uniformitarian modernists and a catastrophist old guard with a hidden
theological agenda.
Multiple Meanings of Uniformity and
Lyell's Creative Confusion
When I was studying freshman geology as an undergraduate at Antioch
College, our professor took us to a hill of travertine (limestone deposited by a
spring), and told us that it was 15,000 years old, according to a principle called
uniformitarianism. A colleague, he told us, had measured the current rate of
accumulation. The principle of uniformity permitted us to assume that this rate
had been constant—and a millimeter per year (or whatever) extrapolated to the
bottom of the pile yielded an age of 15,000 years. If we do not accept the
constancy of nature's laws in space and time, my professor added, we will be
unable to apply any science beyond the immediate present.
Figure 4.3
Agassiz's comment of highest praise jotted alongside his criticisms
in his copy of Lyell's Principles.