We know with certainty that never could man have acquired the sciences and arts by himself guided only by his natural abilities and without the benef… - Ibn Hazm

" "

We know with certainty that never could man have acquired the sciences and arts by himself guided only by his natural abilities and without the benefit of instruction. (This applies, e.g., to) medicine, the knowledge of the physiological temperaments, the diseases and their causes, in all their numerous varieties, and the invention of adequate treatment and cure of each of them by drugs or preparations, which could never have been actually tried out. For how could anyone test every prescription on every disease since this would take tens of thousands of years and necessitate the examination of every sick person in the world?