Friends and acquaintances are the surest passport to fortune.

A happy life is impos­si­ble; the best that a man can attain is a heroic life.

The fundament upon which all our knowledge and learning rests is the inexplicable.

We should be surprised that a matter that generally plays such an important part in the life of man has hitherto been almost entirely disregarded by philosophers, and lies before us as raw and untreated material.

If anyone spends almost the whole day in reading...he gradually loses the capacity for thinking...This is the case with many learned persons; they have read themselves stupid

He who does not enjoy solitude will not love freedom.

The highest, most varied and lasting pleasures are those of the mind.