Tongue The function of muscle is to pull and not to push, except in the case of the genitals and the tongue. - Leonardo da Vinci
Experience Nature 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 Vinci
Mind As every divided kingdom falls, so every mind divided between many studies confounds and saps itself. - Leonardo da Vinci
All existing things are really one. We regard those that are beautiful and rare as valuable, and those that are ugly as foul and rotten The foul and rotten may come to be transformed into what is rare and valuable, and the rare and valuable into what is foul and rotten. - Zhuangzi
What we observe is not nature itself, but nature exposed to our method of questioning. - Werner Heisenberg