Nor is it enough to toughen up his soul; you must also toughen up his muscles.
I do not understand; I pause; I examine.
I study myself more than any other subject. That is my metaphysics, that is my physics.
O human creature,you are the investigator without knowledge, the magistrate without jurisdiction, and all in all, the fool of the farce.
I do not speak the minds of others except to speak my own mind better.
I am myself the matter of my book.