"The study of nature is not a luxury, but a necessity for a happy life."

"The magnitude of pleasure reaches its limit in the removal of all pain. When that state is present, pleasure can be varied, but it cannot be increased, nor can it be diminished, so long as it is not d…"

"I was never anxious to please the mob, for I have not learned what pleases it."

"The time when you should most of all withdraw into yourself is when you are forced to be in a crowd."

"The time when we are best able to enjoy ourselves is when we have least need of enjoyment."