“Today as always, men fall into two groups: slaves and free men. Whoever does not have two-thirds of his day for himself, is a slave, whatever he may be: a statesman, a businessman, an official, or a scholar.”
― Friedrich Nietzsche

There are, as always, social and political aspects to seeing nothing as well. Pythagoras in the sixth century B.C. found it perfectly natural to count slaves as 'nothing,' . . . Slaves, like machines today, were simply taken for granted. These days, we take for granted everything from homeless people sleeping in the street to telephones and computers. We have learned to renormalize these things as part of 'nothing.' Whatever is standard becomes effectively invisible.”
― K.C. Cole, The Hole in the Universe