“It was, of course, a grand and impressive thing to do, to mistrust the obvious, and to pin one’s faith in things which could not be seen!”

-Galen, a Roman doctor/philosopher, on Asclepiades's unwillingness to admit that the kidneys processed urine - despite Galen demonstrating the function of the kidneys to Asclepiades by, well, cutting open a live animal and pointing to the urine flowing from its kidneys to its bladder (search the page for "ligatures" to find Galen's experiment described), among other things.