Isaac La Peyrère (1596-1676) was a French philosopher, lawyer and diplomat. Although brought up a Calvinist, he was later forced to convert to Catholicism. His theological views created quite a stir when he put forward the theory of humans existing before Adam & Eve in an attempt to explain where Cain’s wife came from. He argued that there must have been two creations; first the creation of the gentiles and later that of Adam, as father of the Hebrews.
He published his claims in 1655 in Praeadamitae, upsetting Catholics, Protestants and Jews. Stephen P. Kershaw relates how Peyrère added the testimony of Solon and Plato to bolster his claim, arguing that if Atlantis in 9600 BC, then humans existed earlier than Genesis suggests.
Some of his ideas are widely accepted today(a).