And so, at that stage, although the church regarded any figure that was substantially at variance from 4000 BC as heresy, the French natural historian Georges Louis Leclerc, comte de Buffon, in his Les époques de la nature (1779), calculated the age of the earth, first, as 75,000 years, later as 168,000 years, though his private opinion, never published in his lifetime, was that it was nearer half a million years old.
