Public opinion contains all kinds of falsity and truth, but it takes a great man to find the truth in it. The great man of the age is the one who can put into words the will of his age, tell his age what its will is, and accomplish it. What he does is the heart and the essence of his age, he actualizes his age. The man who lacks sense enough to despise public opinion expressed in gossip will never do anything great.

It is because the method of physics does not satisfy the comprehension that we have to go on further.

Everybody allows that to know any other science you must have first studied it, and that you can only claim to express a judgment upon it in virtue of such knowledge. Everybody allows that to make a shoe you must have learned and practised the craft of the shoemaker, though every man has a model in his own foot, and possesses in his hands the natural endowments for the operations required. For philosophy alone, it seems to be imagined, such study, care, and application are not in the least requisite

To him who looks upon the world rationally, the world in its turn presents a rational aspect. The relation is mutual.

What is rational is actual and what is actual is rational

Not curiosity, not vanity, not the consideration of expediency, not duty and conscientiousness, but an unquenchable, unhappy thirst that brooks no compromise leads us to truth.

The courage of the truth is the first condition of philosophic study.