What is known of the life of this almost forgotten scholar has been collected by G.Weill (De Gulielmi Postelli vita et indole, 1892).

He visited the East, brought back oriental MSS., and was more than once imprisoned on charges of heresy.
He dreamed of converting the Mohammedans, and of uniting the whole world under the empire of France.] In this last stage of the Renaissance, which includes the first quarter of the seventeenth century, soil was being prepared in which the idea of Progress could germinate, and our history of it origin definitely begins with the work of two men who belong to this age, Bodin, who is hardly known except to special students of political science, and Bacon, who is known to all the world.

Both had a more general grasp of the significance of their own time than any of their contemporaries, and though neither of them discovered a theory of Progress, they both made contributions to thought which directly contributed to its subsequent appearance..