Des Époques de la Nature
Buffon’s theory of the earth
Buffon & a Mastodon Tooth
Buffon’s Works
• Histoire Naturelle, Génèrale et Paticulière
Published in 1749 (1st three volumes) &
subsequently. 35 published during Buffon’s
lifetime, laying out all that was known of natural
history at the time. 12 volumes on mammals
(beginning with the horse: a human-centered
ordering!); 9 on birds; 5 on minerals plus
supplements…
• Included: Des Époques de la Nature, a theory of
the earth’s history. Supplementary volume 5,
1778.
Other interests
• Measurements/studies of the strength of
timbers (including issues of scale).
• Agricultural improvements.
• Iron foundry
Buffon’s theory
• Comet collides with the sun.
• Material is ejected, forming the earth and
other planets.
• Earth begins as a glob of magma, slowly
cooling as it orbits the sun.
• Uneven surface forms as the earth cools.
• Ore bodies formed beneath the surface as
the earth began to solidify.
Life
• Eventually the earth cooled enough for water to exist on
the surface; over time the entire surface was covered by
the subsequent rains.
• Complex chemical processes get underway.
• New kinds of rock (sedimentary) begin to form; at the
same time, life begins.
• Limestone (made of the shells of tiny organisms) records
the life of the ancient earth.
• Sediments harden, sea level retreats (as bubbles near
the earth’s surface burst, creating new spaces for water
to flow down into).
• Plants begin on land as the sea retreats
Volcanic Activity
• Again (as for de Maillet and, later, Werner),
volcanoes are explained as due to underground
combustion of plant materials accumulated in
coal beds.
• These combustible materials actually burst into
flame when exposed to water, hence the
proximity of most active volcanoes to the sea.
• Foundering of the land joining NA to Europe
forms the Atlantic Ocean.
More on Life
• Life an inherent property/tendency of
matter.
• Organic molecules arise by chemical
processes acting on the earth.
• First living things not necessarily simple–
instead, Buffon favours spontaneous
formation of fully-fledged life. The heat of
the early earth made the process more
vigourous at the beginning than it is today.
Evolution
• As the poles cooled first, life begins there.
• At first tropical life is formed, then life adapted to
colder conditions. Rhino and elephant fossils in
the North are assumed to indicate much warmer
climate then.
• No descent here.
• But degeneration of animals in inferior
environments (N.A.) is a kind of ‘evolution’ that
Buffon did believe in, although (clearly) this
process is not ‘progressive’ or adaptive.
Human Beings
• Reason is not matter: A special gift for our
species…
• But life and even thinking things may well
exist elsewhere in the universe.
2 time scales
• 1778: 75,000 years.
• Unpublished until the 19th Century: 3,000,000
years. (Influenced here by the thickness of
sedimentary strata and ideas about the time
required to form them.)
• Why suppress one figure while adopting another
that’s equally unacceptable to conventional
religious views? (A matter of what the audience
would entertain?)
• Similarly, the 7 epochs (‘milestones in time’)
seem a half-hearted attempt to appease
religious worries.(see p. 84)
Calculating the Earth’s Age
• Another clock like de Maillet’s: A long process,
and some measure of the rate at which it has
gone on.
• But a different basis: The original, molten earth
has since been steadily cooling.
• Experiments with iron balls of different sizes at
Buffon’s foundry provide an estimate of how long
the earth would take to cool from just barely
solid to its present temperature (taken from a
cave near the foundry).
On Ecology
• “The Earth makes the plants; the Earth and the
plants make the animals.”
• North American species are degenerate forms
descended from European & Asian species.
The influence of an unhealthy environment is to
blame for this; such environments have less
impact on humans than they have on animals,
but the impact is there nonetheless.
• Dispute with Jefferson over the N.American
bison, mastodons & other impressive N.
American fauna.
Philosophical Ideas
• Knowledge expands by noting resemblances & relations
between things.
• Anything absolutely unique is therefore unknowable.
• This applies to God in particular.
• Science is confined to secondary causes and can say
nothing about God.
• These causes tell us how things came to be a certain
way, but they don’t explain why (i.e. they provide no
insight into purpose).
• Scientists should appeal to causes in operation today,
not to unknown/catastrophic causes (an early
uniformitarian, in this regard).
Push-back
• Faculty of Theology at U. Paris– Buffon escaped
‘censure’ only by dismissing his views as ‘pure
philosophical speculation,’ and proposing a
reading of Genesis that took God to have
created the materials of the world (after which
secondary causes took over…).
• What does this threat of censure involve?
Official, authoritative disapproval with real social
consequences: Buffon might have been unable
to continue in his role as keeper of the king’s
garden, which Buffon had turned into a
scientific/botany position.