Quote by Immanuel Kant
"Act as if the maxim of your action were to become by your will a universal law of nature."
More from Immanuel Kant
"Act only according to that maxim whereby you can at the same time will that it should become a universal law."
"Sapere aude! Dare to know! Have courage to use your own understanding."
"Two things awe me most: the starry sky above and the moral law within."
"Happiness is not an ideal of reason but of imagination."