If you are distressed by anything external, the pain is not due to the thing itself but to your own estimate of it; and this you have the power to revoke at any moment.
-- Marcus Aurelius, Roman Emperor
I was about to reply that apparently Marcus Aurelius had never put his hand on a burning stove, but then I remembered that he had probably been taught about Mucius Scaevola about a million times.
This is our monthly thread for collecting these little gems and pearls of wisdom, rationality-related quotes you've seen recently, or had stored in your quotesfile for ages, and which might be handy to link to in one of our discussions.