"These creatures are among us, although morphologically they do not differ from us; we must not posit a difference of essence, but a difference of behavior. In my science fiction I write about about them constantly. Sometimes they themselves do not know they are androids. Like Rachel Rosen, they can be pretty but somehow lack something; or, like Pris in We Can Build You, they can be absolutely born of a human womb and even design androids — the Abraham Lincoln one in that book — and themselves be without warmth; they then fall within the clinical entity "schizoid," which means lacking proper feeling. I am sure we mean the same thing here, with the emphasis on the word "thing." A human being without the proper empathy or feeling is the same as an android built so as to lack it, either by design or mistake. We mean, basically, someone who does not care about the fate which his fellow living creatures fall victim to; he stands detached, a spectator, acting out by his indifference John Donne's theorem that "No man is an island," but giving that theorem a twist: that which is a mental and a moral island is not a man."