"The most useful and honorable science is that of man; and the most properly studied book is the world."

"Let us then, in the first place, lay down as an incontestable maxim that the first impulses of nature are always right."

"Conscience is the voice of the soul; the passions are the voice of the body."

"The rich man, in his bed of down, does not know the value of the poor man's sleep."

"To be truly free, we must obey only those laws we have prescribed for ourselves."