A cat ain't ever anybody's slave or serf or servant， and can't be—it ain't in him to be. And so， he don't have to obey anybody. He is the only creature in heaven or earth or anywhere that don't have to obey somebody or other， including the angels.

—The Refuge of The Derelicts， Novelist， Mark Twain

貓從來不是任何人的奴隸、農奴或仆人，也不可能是——它自身并沒有這樣的特質。所以，它無需服從任何人。無論是在天堂還是塵世，或者任何地方，貓都是唯一一種無需服從某個人類或是其他生物的物種，貓甚至無需服從天使。

——《廢物收容所》馬克·吐溫，小說家