"You see by the papers how I'm annoyed by a set of blockheads who write about the imperfection of the cowpox, as a vaccine, without any knowledge scarcely of its phenomena."

"My greatest ambition has always been to be useful to mankind."

"The deviation of man from the state in which he was originally placed by nature seems to have proved to him a prolific source of diseases."

"I have often been surprised at the credulity of mankind; but I have also been surprised at their obstinacy."

"I have always endeavoured to act upon the principle, that what is right to be done, should be done with all our might."