Epicurus, ~300 BC
Letter on Happiness
Epicurus wrote this letter to a student named Menoeceus. It is one of the oldest surviving instructions on how to live well. Key passages:
Let no one delay the study of how to live well while young, nor grow tired of it when old. For no one is too early or too late to care for the health of the soul.
Get used to the idea that death is nothing to us. For every good and every evil lies in sensation — and death is the end of sensation. Therefore the most frightening of evils, death, is nothing to us: while we exist, death is not present; and when death is present, we no longer exist.
He is foolish who says he fears death not because it will hurt when it arrives, but because it hurts to expect it. What causes no trouble when present causes only empty pain while awaited.
The wise man neither rejects Life nor fears its end. Life does not offend him, and he does not think it an evil to stop living. Just as he chooses not simply the largest amount of food but the most pleasant, so he enjoys not the longest time but the most pleasant.
We must remember that the future is neither fully ours nor fully not ours, so that we neither expect it as certain to come, nor despair of it as certain not to come.