"Nature is nowhere accustomed more openly to display her secret mysteries than in cases where she shows tracings of her workings apart from the beaten paths; nor is there any better way to advance the …"

"All we know is still infinitely less than all that still remains unknown."

"I confess that I have been led to embrace this opinion by a careful consideration of the structure and use of the valves in the veins."

"There is no science which does not spring from pre-existing knowledge, and no certain and definite idea which has not derived its origin from the senses."

"The human body is a machine, but it is also a living soul."