Quote by Marcus Aurelius
"If you would be a real seeker after truth, you must at least once in your life doubt, as far as possible, all things."
More from Marcus Aurelius
"You have power over your mind - not outside events. Realize this, and you will find strength."
"The obstacle in the path becomes the path."
"It is not death that a man should fear, but never beginning to live."
"Everything we hear is an opinion, not a fact. Everything we see is a perspective, not the truth."