“Knowing yourself is the beginning of all wisdom.”

“It is the mark of an educated mind to be able to entertain a thought without accepting it.”

“Educating the mind without educating the heart is no education at all.”

“One swallow does not make a summer, neither does one fine day; similarly one day or brief time of happiness does not make a person entirely happy.”

“Philosophy can make people sick.”

“For the things we have to learn before we can do them, we learn by doing them.”

“Freedom is obedience to self-formulated rules.”

“With the truth, all given facts harmonize; but with what is false, the truth soon hits a wrong note.”

“A man without regrets cannot be cured.”