Why you should become a Bible-believing anarchist
who also believes the universe was created around 4004 B.C.
According to de Buffon’s unpublished manuscript, he wanted to say that the sedimentary rocks probably took at least three million years to form, but Buffon’s fear of contemporary reaction to this great date led him to put a much smaller figure of 75,000 years in the published book. The Catholic church in France was still powerful.
There was no such thing as "geology" in the modern sense before James Hutton and Charles Lyell. They made up "uniformitarianism" and "deep time" to get rid of God. Not all evolutionary propagandists were open and public about that, much less aggressive; many sought to persuade the public by toning down their anti-Biblical conclusions. Mortenson notes that
In 1778 Georges-Louis Comte de Buffon (1708-1788) postulated that the earth was the result of a collision between a comet and the sun and had gradually cooled from a molten lava state over at least 75,000 years (a figure based on his study of cooling metals).8
Mortenson is a creationist, but has done so much reading in evolutionary studies that he speaks like an evolutionist. Notice that Mortenson does not say Buffon "made up the whole comet-story out of thin air, desperate to evade God's revelation in the Bible." Mortenson says he "postulated" the idea. There. That sounds more "scientific." Here's the footnote:
8. Georges Comte de Buffon, Les époques de la nature (Paris: n.p., 1778). According to de Buffon’s unpublished manuscript, he actually believed that the sedimentary rocks probably took at least three million years to form. But Buffon’s fear of contemporary reaction to this great date led him to put 75,000 years in the published book.
Did Buffon "actually believe" that story? God will judge. But he knew that "millions of years" was a fringe idea at that time, and many Christians would balk at it. So scientific accuracy would take a back seat to Marketing. The priority isn't "the facts." The priority is moving people away from the Bible. Buffon was not neutral. Many like him adopted a "methodological naturalism" which excluded God from their calculations.
Buffon’s Published Estimate
In his Histoire naturelle (1749), Buffon described experiments with cooling iron spheres.
From this, he estimated the Earth’s age at about 75,000 years, already far beyond Ussher’s 4004 BC chronology.
Even this number provoked the Sorbonne theologians, and Buffon was forced to issue a kind of retraction — stating that he only spoke “as a philosopher,” but as a Christian he believed in the Mosaic chronology.
Buffon’s Private Convictions
Surviving notes and an unpublished manuscript (only uncovered in the 20th century) reveal that Buffon thought the sedimentary strata alone must have required at least 3 million years to form.
This was not just a guess: he combined observations of erosion, deposition, and fossil succession with his physics of heat loss.
He understood perfectly well that publishing such figures would invite ecclesiastical condemnation — hence the drastic reduction in print.
Why Buffon Matters
He was arguably the first naturalist to push geology toward truly deep time using semi-quantitative methods.
His caution in publication shows how fraught the “nature-grace” split you mentioned could be: natural philosophy pointed to millions of years, but public orthodoxy required lip service to Scripture.
Later geologists (Hutton, Lyell) could openly build on the idea of millions of years, but Buffon had to disguise his conclusions.
ߑ? So yes — your note is right, and it makes Buffon more important than many on your list who never directly confronted chronology. He’s a pivotal example of someone whose epistemology and unpublished convictions went much farther than his official print.
For evolutionists, marketing is more important than accuracy. The details don't matter that much, as long as the audience breaks away from the Biblical chronology.