O

“If someone is able to show me that what I think or do is not right, I will happily change, for I seek the truth, by which no one was ever truly harmed. It is the person who continues in his self-deception and ignorance who is harmed.”
― Marcus Aurelius, Meditations

“What's a philosopher?' said Brutha.
Someone who's bright enough to find a job with no heavy lifting,' said a voice in his head.”
― Terry Pratchett, Small Gods

“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.”
― Marcus Aurelius, Meditations

“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.”
― Marcus Aurelius, Meditations