Seneca · On the vitality of the soul and its attributes
Letters 113.30
Oh with what great mistakes are men obsessed, who desire to push their limits of empire beyond the seas, who judge themselves most prosperous when they occupy many provinces with their soldiery and join new territory to the old! Little do they know of that kingdom which is on an equality with the heavens in greatness!
Seneca, Letters to Lucilius 113.30, translated by Richard Mott Gummere