"I have often observed, that those who have a great esteem for their own opinions, are very apt to despise those of others."

"I once kept a viper in a sealed glass jar until it died, to observe the effects of air deprivation."

"I have seen a piece of glowing wood continue to shine in a vacuum, proving that not all light requires air."

"If a man will not be a fool, he must not be a dogmatist."

"The corpuscular philosophy is the most intelligible of all."