Science fiction offers two immediate things to the reader: the ability to travel to far away times and places, to alternate histories and to gorgeously realized other worlds. It also often gives us a sense of great familiarity – it is, after all, other humans exploring the universe. This duality of the genre lets the author take a modern human and put him in an altogether alien environment. The author gives this person a series of immense obstacles to overcome so as to see how he will react. By the end of the novel, both the author and, by extension, the audience will hopefully learn something about the human condition. In this way, science fiction can be thought of as a great thought experiment – projecting modern ideas, philosophies, mores, norms etc. onto a society inherently deprived of those very attributes. This lets the author satirize modern society, show any glaring problems with it, and often, predict where it will end up. But this is not all that science fiction does. Perhaps by putting the recognizable man of this world into the alien-ness of that world, we will realize something in humankind that is inherent to everyone, across time. Often, in the words of Brian Aldiss, science fiction’s main goal is to define what makes us human.
But what of the actual setting of the story? How do the starscapes, distant planets and future Earths contribute to the definition of humanity that the author is trying to express? After reading Frankenstein, one of the first science fiction novels, we can see that the setting is often an extreme representation of locations as to mirror the emotions and mindsets of the characters inhabiting them. The monster in this book is at home in the frigid arctic and can dance around the mountains of Switzerland with no hesitation. In much the same way, the androids of DADES can live on the ruins of Earth with no problem. In fact, they would prefer to live on the radioactive-dust covered surface of our planet than work as slaves for the rich on Mars. The androids in DADES mirror the monster in both their ability to live in inhospitable landscapes and their role as antagonist – and by extension as the way to define humanity.
Knowing this, does DADES fall into the definition of science fiction set by Aldiss? The answer comes down to whether or not defining humanity is of central importance to Philip K. Dick. In the first half, where we are introduced to Nexus-6 androids – “capable of selecting within a fielda field of two trillion constituents, or ten million separate neural pathways,” – which are indistinguishable from humans without either taking a bone marrow biopsy or administering one of two advanced ‘empathy tests’. This is the key to the story. In DADES, we are led to believe that empathy is the penultimate human trait. Androids – near perfect replicas of humans – do not produce empathy naturally, not even the Nexus-6 models. Dick appears to use this as the distinguishing feature of humanity in the novel, however with a more subtle reading, it is clear that he does not want empathy – a trait raise to religious status in post-apocalypse Earth – to be the sole definition of humanity. Take Iran Deckard for instance, the wife of Richard Deckard, who has to ‘dial in’ artificially to be depressed at the world she lives in. This is arguably one of the more human quirks, paradoxical as it may be, that we see in the novel. She realizes that as a human, she should be irrevocably depressed by living in the world she does; yet there she is, artificially making herself depressed – an attitude she can change with the turn of a knob.
Dick did not right DADES to show us what he believes humanity is. He instead wants us to consider what makes us human in regard to near-perfect human replicas. In a society that has rejected androids, he wants us to question whether or not that society has rejected humans.
 Modern of course is relative to the author’s time – in DADES’ case, it would be a person from 1968.
 See 1984 for a perfect example – what was once a warning seems to be overwhelmingly used as an instruction manual.
 In a technique dating back to at least Thomas Aquinas, where one uses what a thing is not to define what it is.
 Do Androids Dream of Electric Sheep, page 28