Can the man say, Fiat lux, Let there be light; and out of chaos make a world? Precisely as there is light in himself, will he accomplish this.

Thomas Carlyle (1795-1881) Scottish essayist and historian

Lecture (1840-05-12), “The Hero as Poet,” Home House, Portman Square, London
    (Source)

Talking about Shakespeare and his creativity.

The lecture notes were collected by Carlyle into On Heroes, Hero-Worship, & the Heroic in History, Lecture 3 (1841).