“The investigation of the truth is in one way hard, in another easy. An indication of this is found in the fact that no one is able to attain the truth adequately, while, on the other hand, no one fails entirely, but everyone says something true about the nature of all things, and while individually they contribute little or nothing to the truth, by the union of all a considerable amount is amassed.”

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

“And further, observing that all this indeterminate substance is in motion, and that no true predication can be made of that which changes, they supposed that it is impossible to make any true statement about that which is in all ways and entirely changeable. For it was from this supposition that there blossomed forth the most extreme view of those which we have mentioned, that of the professed followers of Heraclitus, and such as Cratylus held, who ended by thinking that one need not say anything, and only moved his finger; and who criticized Heraclitus for saying that one cannot enter the same river twice, for he himself held that it cannot be done even once.”

“In all things of nature there is something of the marvelous.”

“Some men are just as sure of the truth of their opinions as are others of what they know.”

“For though we love both the truth and our friends, piety requires us to honor the truth first.”

“All human actions have one or more of these seven causes: chance, nature, compulsion, habit, reason, passion, and desire.”