He was a man of erudition, but he owed his fame chiefly to his personality.
The noticeable barrenness of Italian literature at this period is referable to the fact that men of genius and talent devoted themselves to erudition and struggled to express their thoughts and feelings in a speech which was not natural.
Resolute in recognizing erudition as the chief concern of man, he sighed over the folly of popes and princes, who spent their time in wars and ecclesiastical disputes when they might have been more profitably employed in reviving the lost learning of antiquity.
Nicholas himself was a man of vast erudition, and his friend Aeneas Silvius (later Pope Pius II.) said of him that "what he does not know is outside the range of human knowledge."
Penetrated by the conviction that ignorance was the worst of the inveterate evils of old Russia, a pitiless enemy of superstition of every sort, a reformer by nature, overflowing with energy and resource, and with a singularly lucid mind armed at all points by a farreaching erudition, Prokopovich was the soul of the reforming party after the death of Peter the Great.