"A life without investigation is not worth living."

"By harming a horse, you decrease his excellence. Thus, by harming a person, you decrease their excellence."

"Those whose hearts are fixed on reality itself deserve the title of Philosophers."

"'Excellence' is not a gift, but a skill that takes practice. We do not act 'rightly' because we are 'excellent', in fact we achieve 'excellence' by acting 'rightly'."

"Will life be worth having, if that higher part of man be destroyed, which is improved by justice and depraved by injustice?"

"If you do not take an interest in the affairs of your government, then you are doomed to live under the rule of fools."

"If the truth of all things that are is always in our soul, then the soul must be immortal, so you should take courage and whatever you do not happen to know, that is to remember, at present, you must endeavor to discover and recollect I cannot swear to everything I have said in this argument but one thing I am ready to fight for in word and deed, that we shall be better, braver and more active men if we believe it right to look for what we do not know, than if we think we cannot discover it and have no duty to seek it."

"The key is not to live but to live well."

"All men are by nature equal, made all of the same earth by one Workman; and however we deceive ourselves, as dear unto God is the poor peasant as the mighty prince."

"Is there any self-existent fire? and do all those things which we call self-existent exist? or are only those things which we see, or in some way perceive through the bodily organs, truly existent, and nothing whatever besides them? And is all that which we call an intelligible essence nothing at all, and only a name?"