Virgil to Dante

“Why are thy thoughts thus riveted?” my guide
Exclaim’d, “that thou hast slack’d thy pace? or how
Imports it thee, what thing is whisper’d here?
Come after me, and to their babblings leave
The crowd. Be as a tower, that, firmly set,
Shakes not its top for any blast that blows!
He, in whose bosom thought on thought shoots out,
Still of his aim is wide, in that the one
Sicklies and wastes to nought the other’s strength.”

-- Purgatorio, Canto V (Cary translation)