I can highly recommend Do Androids Dream of Electric Sheep? by Philip K. Dick. The movie Blade Runner was 'based' on this book. It asks questions about what it means to be human. There are three-four groups to whom the question might be put.
There are citizens like Iran, the lead character's wife. She is trying to come to terms with the fact that the world is crumbling around her. TV is her constant companion. With a machine to select your every mood, she chooses depression because it gives feeling into the way things really are. This is a human sensitive to the decaying world, disconnected from life and her husband. She also engages in the corporate, electronically mediated religion of Mercerism.
Then there is John. The radioactive fallout from the last world war has affected his brain. He failed an IQ test to allow him to emigrate to Mars or to even be able to mate. He is sub-human, a chicken head. Yet John is able to empathize with others, spiders and even androids.
Then there are bounty hunters - 'retiring' androids that are quite human in appearance, even in physical attraction. Deckard is caught in his feelings; are androids sub-human and hence retired, or are they human and hence is he a murderer?
Finally, there are the androids, created to do menial work. They are lifelike, some people off world even have sexual relations with them. Some of them kill their owners and return to the Earth. Yet, the very test that Deckard uses to determine whether they are human or not, their lack of ability into empathize or understand the cult of Mercerism (itself an involved theme in the book) leads him to decide that they are not.
To understand the situation of other creatures, to imaginatively enter their existence and feel their pain makes some biological life (ourselves at least) unique. In Dick's world, androids cannot do this. This makes me think of something Raimond Gaita wrote about in his book A Common Humanity, that people's worth is made clearer in the love a saint can show for them. He gives the example of a nun who cared for mentally ill patients with no hope of a flourishing human life far better than the health professionals because she did so non-condescendingly. This was because of the love she held for them. Love and empathy. Without these we dehumanize others. Likewise, when Davros made the Daleks free of pity (this is Dr Who for those who don't know), he dehumanized both the Daleks and everyone they met.