Man does not value or despise any place as the cause of his happiness or unhappiness, but he makes the whole matter depend upon himself and considers himself a citizen of the city of God which is made up of men and gods.
Musonius Rufus, Lecture ix
Now, since, in general, toil and hardship are a necessity for all men, both for those who seek the better ends and for those who seek the worse, it is preposterous that those who are pursuing the better are not much more eager in their efforts than those for whom there is small hope of reward for all their pains... Shall we not be ready to endure hardship for the sake of complete happiness? For surely there is no other end in becoming good than to become happy and to live happily for the remainder of our lives.
Musonius Rufus, Lecture vii