Discourses, "On the Same" (§1)

“If these things are true, and if we are not silly, and are not acting hypocritically when we say that the good of man is in the will, and the evil too, and that everything else does not concern us, why are we still disturbed, why are we still afraid? The things about which we have been busied are in no man’s power; and the things which are in the power of others, we care not for. What kind of trouble have we still?”