“The worst thing you can possibly do is worrying and thinking about what you could have done”

“The thoughts written on the walls of madhouses by their inmates might be worth publicizing”

“Erudition can produce foliage without bearing fruit.”

“We cannot remember too often that when we observe nature, and especially the ordering of nature, it is always ourselves alone we are observing”

“Nothing is more conducive to peace of mind than not having any opinions at all”

“To prejudge other men's notions before we have looked into them is not to show their darkness but to put out our own eye”