Epictetus 3.22.100-104
Now the spirit of patient endurance the Cynic must have to such a degree that common people will think him insensate and a stone; nobody reviles him, nobody beats him, nobody insults him; but his body he has himself given for anyone to use as he sees fit. For he bears in mind that the inferior, in that respect in which it is inferior, must needs be overcome by the superior, and that his body is inferior to the crowd—the physically weaker, that is, inferior to the physically stronger. Therefore, he never enters this contest where he can be beaten, but immediately gives up what is not his own; he makes no claim to what is slavish. But in the realm of the moral purpose, and the use of his sense-impressions, there you will see he has so many eyes that you will say Argus was blind in comparison with him. Is there anywhere rash assent, reckless choice, futile desire, unsuccessful aversion, incompleted purpose, fault-finding, self-disparagement, or envy?