Meditations VIII.48

Never forget that the ruling Reason shews itself unconquerable when, concentrated in itself,⁴⁹ it is content with itself so it do nothing that it doth not will, even if it refuse from mere opposition⁵⁰ and not from reason—much more, then, if it judge of a thing on reasonable grounds and advisedly. Therefore the Mind, unmastered by passions, is a very citadel, for a man has no fortress more impregnable⁵¹ wherein to find refuge and be untaken for ever. He indeed who hath not seen this is ignorant, but he that hath seen it and takes not refuge therein is luckless.

• 49.See vii. 28.
• 50.xi. 3. In both places Marcus seems to have the Christians in mind.
• 51.Compare Fronto’s letter to Verus, ii. 1 (of Marcus): arcem munitam et invictam et inexpugnabilem quae in fratris tui pectore sita est.

  Fronto’s Latin, in translation: “the fortified, unconquered, and impregnable citadel that is in your brother’s breast.”