Immanuel Kant

“Act only on that maxim whereby thou canst at the same time will that it should become a universal law.”

“So act as to treat humanity, whether in thine own person or in that of any other, in every case as an end withal, never as means only.”

“We must not be in the least prejudiced in favour of the existence of the things, but be quite indifferent in this respect, in order to play the judge in things of taste.”