"The blood of a living creature is a most elaborate and curiously contrived liquor."

"I have often observed that those who are most confident in their own opinions, are generally the least able to defend them."

"I have always looked upon the study of nature as a means of enlarging the human mind."

"I have often thought that the greatest obstacle to the progress of knowledge is the obstinacy of men in adhering to their old opinions."

"I have always been of the opinion, that the best way to understand the nature of things, is to examine them by experiments."