Marcus Aurelius
Meditations 3.4
Do not waste the remainder of thy life in thoughts about others, when thou dost not refer thy thoughts to some object of common utility. For thou losest the opportunity of doing something else when thou hast such thoughts as these,—What is such a person doing, and why, and what is he saying, and what is he thinking of, and what is he contriving, and whatever else of the kind makes us wander away from the observation of our own ruling power. We ought then to check in the series of our thoughts everything that is without a purpose and useless, but most of all the over-curious feeling and the malignant; and a man should use himself to think of those things only about which if one should suddenly ask, What hast thou now in thy thoughts? with perfect openness thou mightest immediately answer, This or That; so that from thy words it should be plain that everything in thee is simple and benevolent, and such as befits a social animal, and one that cares not for thoughts about pleasure or sensual enjoyments at all, nor has any rivalry or envy and suspicion, or anything else for which thou wouldst blush if thou shouldst say that thou hadst it in thy mind. For the man who is such, and no longer delays being among the number of the best, is like a priest and minister of the gods, using too the [deity] which is planted within him, which makes the man uncontaminated by pleasure, unharmed by any pain, untouched by any insult, feeling no wrong, a fighter in the noblest fight, one who cannot be overpowered by any passion, dyed deep with justice, accepting with all his soul everything which happens and is assigned to him as his portion; and not often, nor yet without great necessity and for the general interest, imagining what another says, or does, or thinks. For it is only what belongs to himself that he makes the matter for his activity; and he constantly thinks of that which is allotted to himself out of the sum total of things, and he makes his own acts fair, and he is persuaded that his own portion is good. For the lot which is assigned to each man is carried along with him and carries him along with it. And he remembers also that every rational animal is his kinsman, and that to care for all men is according to man's nature; and a man should hold on to the opinion not of all, but of those only who confessedly live according to nature. But as to those who live not so, he always bears in mind what kind of men they are both at home and from home, both by night and by day, and what they are, and with what men they live an impure life. Accordingly, he does not value at all the praise which comes from such men, since they are not even satisfied with themselves.
Marcus Aurelius, Meditations 3.4, translated by George Long
Fritter not away what is left of thy life in thoughts about others, unless thou canst bring these thoughts into relation with some common interest. For verily thou dost hereby cut thyself off from other work, that is, by thinking what so and so is doing and why, what he is saying, having what in mind, contriving what, and all the many like things such as whirl thee aside from keeping close watch over thine own ruling Reason.
We ought therefore to eschew the aimless and the unprofitable in the chain of our thoughts, still more all that is over-curious and ill-natured, and a man should accustom himself to think only of those things about which, if one were to ask on a sudden, What now in thy thoughts? thou couldest quite frankly answer at once, This or that; so that thine answer should immediately make manifest that all that is in thee is simple and kindly and worthy of a living being that is social and has no thought for pleasures or for the entire range of sensual images, or for any rivalry, envy, suspicion, or anything else, whereat thou wouldest blush to admit that thou hadst it in thy mind.
For in truth such a man, one who no longer puts off being reckoned now, if never before, among the best, is in some sort a priest and minister of the Gods, putting to use also that which, enthroned within him, keeps the man unstained by pleasures, invulnerable to all pain, beyond the reach of any wrong, proof against all evil, a champion in the highest of championships—that of never being overthrown by any passion—dyed in grain with justice, welcoming with all his soul everything that befalls and is allotted him, and seldom, nor yet without a great and a general necessity, concerning himself with the words or deeds or thoughts of another. For it is only the things which relate to himself that he brings within the scope of his activities, and he never ceases to ponder over what is being spun for him as his share in the fabric of the Universe, and he sees to it that the former are worthy, and is assured that the latter is good. For the fate which is allotted to each man is swept along with him in the Universe as well as sweeps him along with it.
And he bears in mind that all that is rational is akin, and that it is in man's nature to care for all men, and that we should not embrace the opinion of all, but of those alone who live in conscious agreement with Nature. But what sort of men they, whose life is not after this pattern, are at home and abroad, by night and in the day, in what vices they wallow and with whom—of this he is ever mindful. Consequently he takes no account of praise from such men, who in fact cannot even win their own approval.
Marcus Aurelius, Meditations 3.4, translated by C. R. Haines