Meditations 7.13

Just as it is with the members in those bodies which are united in one, so it is with rational beings which exist separate, for they have been constituted for one co-operation. And the perception of this will be more apparent to thee if thou often sayest to thyself that I am a member melos of the system of rational beings. But if [using the letter r] thou sayest that thou art a part meros, thou dost not yet love men from thy heart; beneficence does not yet delight thee for its own sake; thou still doest it barely as a thing of propriety, and not yet as doing good to thyself.

Marcus Aurelius, Meditations 7.13, translated by George Long

The principle which obtains where limbs and body unite to form one organism, holds good also for rational things with their separate individualities, constituted as they are to work in conjunction. But the perception of this shall come more home to thee, if thou sayest to thyself, I am a limb of the organized body of rational things. But if [using the letter R] thou sayest thou art but a part, not yet dost thou love mankind from the heart, nor yet does well-doing delight thee for its own sake. Thou dost practise it still as a bare duty, not yet as a boon to thyself.

Marcus Aurelius, Meditations 7.13, translated by C. R. Haines