You will find rest from vain fancies if you perform every act in life as though it were your last. — Marcus Aurelius Antoninus. Roman emperor from 161 to 180
If you are distressed by anything external, the pain is not due to the thing itself, but to your estimate of it; and this you have the power to revoke at any moment.
Look well into thyself; there is a source of strength which will always spring up if thou wilt always look there.
Never esteem anything as of advantage to you that will make you break your word or lose your self-respect.
Never let the future disturb you. You will meet it, if you have to, with the same weapons of reason which today arm you against the present.