Eternal vigilance is the price of knowledge.
Before he sets out, the traveler must possess fixed interests and facilities to be served by travel.
I like to walk about among the beautiful things that adorn the world; but private wealth I should decline, or any sort of personal possessions, because they would take away my liberty.
Unmitigated seriousness is always out of place in human affairs.
Better not be a hero than work oneself up into heroism by shouting lies.
The great difficulty in education is to get experience out of ideas.