Epictetus

“For this is your duty, to act well the part that is given to you; but to select the part, belongs to another.”

“Men are disturbed not by things, but by the views which they take of things.”

“Take away then aversion from all things which are not in our power, and transfer it to the things contrary to nature which are in our power. But destroy desire completely for the present.”

“My opinions alone are mine, and they cannot be taken from me, and I am satisfied while I have them, wherever I may be and whatever I am doing.”