人生的快樂取決於你思維的品質。因此，依此看管你的想法，注意勿持有違背美德與常理的觀點。The happiness of your life depends upon the quality of your thoughts: therefore, guard accordingly, and take care that you entertain no notion unsuitable to virtue and reasonable nature.

The happiness of your life depends upon the quality of your thoughts: therefore, guard accordingly, and take care that you entertain no notion unsuitable to virtue and reasonable nature.
— Marcus Aurelius, Roman Emperor
人生的快樂取決於你思維的品質。因此，依此看管你的想法，注意勿持有違背美德與常理的觀點。

– 馬爾庫斯‧奧列里烏斯 (121-180) 羅馬帝國時期的最後一位君主，任內討伐日耳曼民族。他也是哲學家，其著作 Meditations (沉思錄) 闡述他的哲學理念並表現出羅馬文明最優異之處。