If, in conformity to right reason, you transact whatever affairs you have in hand with attention, steadiness, and benevolence, and without suffering any thing foreign to your present purpose to interfere, you pay the same deference to the divine monitor within you, as if you were the next moment to part for ever; if you can thus persevere, inattentive to any thing further, and without shrinking from any difficulty, and act with simplicity and energy, according to the nature of the present business, with an heroic regard to truth in all your words; you will thus secure a happy life.

It is not in the power of any one to prevent your acting thus.

Marcus Aurelius, Meditations