A man should always have these two rules in readiness. First, to do only what the reason of your ruling and legislating faculties suggest for the service of man. Second, to change your opinion whenever anyone at hand sets you right and unsettles you in an opinion, but this change of opinion should come only because you are persuaded that something is just or to the public advantage, not because it appears pleasant or increases your reputation.
Marcus AureliusIf someone can prove me wrong and show me my mistake in any thought or action, I shall gladly change. I seek the truth, which never harmed anyone: the harm is to persist in one's own self-deception and ignorance.
Marcus AureliusLive not one's life as though one had a thousand years, but live each day as the last.
Marcus AureliusBe not disgusted, nor discouraged, nor dissatisfied, if thou dost not succeed in doing everything according to right principles; but when thou bast failed, return back again, and be content if the greater part of what thou doest is consistent with man's nature, and love this to which thou returnest
Marcus Aurelius