Although nature commences with reason and ends in experience it is necessary for us to do the opposite, that is to commence with experience and from this to proceed to investigate the reason.
Leonardo da VinciO painter skilled in anatomy, beware lest the undue prominence of the bones, sinews and muscles cause you to become a wooden painter from the desire to make your nude figures reveal all.
Leonardo da VinciIf you do not rest on the good foundation of nature, you will labour with little honor and less profit.
Leonardo da Vinci