that the morals of Socrates and the philosophy of Plato were only the development of it and that an inscription in the temple of Greece, that of Delphi, commended it, after that of the golden mean, as the very teaching of the God whom they worshipped there[1]: Nothing in excess, and know Thyself, contained in few words the doctrine of the sages, and presented for their meditation the principles upon which reposed virtue and wisdom which is its consequence. Nothing further was necessary to electrify the soul of Heraclitus and to develop the germs of genius, which until the moment when he read these two sentences were buried in a cold inertia.
I will not pause therefore to prove the necessity of a knowledge without which all other is but doubt and presumption. I will only examine, in a brief digression, if this knowledge is possible. Plato, as I have said, made the whole edifice of his doctrine rest upon it; he taught, according to Socrates, that ignorance of one's self involves all ignorance, all mistakes, all vices, and all misfortunes; whereas knowledge of one's self, on the contrary, draws all virtue and all goodness[2]: so that it cannot be doubted that this knowledge might be considered possible, since its impossibility merely questioned would render its system null and void. However, as Socrates had said that he knew nothing, in order to distinguish himself from the sophists of his day who pretended to know everything; as Plato had constantly used in his teachings that sort of dialectic which, proceeding toward truth by doubt, consists in defining things for what they are, knowing their essence, distinguishing those which are real from those which are only illusory; and above all as the favourite maxim of these two philosophers had been that it was necessary to renounce all manner of prejudices, not pretending to know that of which one is ignorant, and giving assent only to clear and evident truths; it came to
