As Cavernas de Aco

Isaac Asimov was famous for his stories involving robots, and for inventing the Three Laws of Robotics:

First Law
A robot may not injure a human being or, through inaction, allow a human being to come to harm.

Second Law
A robot must obey the orders given it by human beings except where such orders would conflict with the First Law.

Third Law
A robot must protect its own existence as long as such protection does not conflict with the First or Second Laws.

The earlier stories took place on an Earth not too far in future. In this novel he jumps several millennia into the future. With the aid of robots, some people have colonized 50 worlds near Earth, and they are called The Spacers. They do not want much to do with Earth, but there is some trade. Earth has in the meantime become an overcrowded megalopolis of enclosed levels inhabited by people who have become agoraphobic to an extreme. The population is huge, and taking care of them requires severe rationing measures and artificial foods. Interestingly, the total population is given as 8 billion, not much more than we have today, and less than the maximum we are projected to reach. Asimov was someone who worried about overpopulation to perhaps an extreme degree.

Then a Spacer is murdered, and a detective form Earth named Elijah Bailey is assigned to the case. But the Spacers insist that one of their "people" be involved, only that turns out to be a humaniform robot named R. Daneel Olivaw, who can pass for being a human being. So the novel combines a developing relationship between these characters with a murder mystery, something Asimov was also fond of writing. This novel is the first of three. The second, The Naked Sun is set on the planet Solaria, and a third, The Robots of Dawn is set on the planet Aurora. The three novels explore in some sense different settings: Earth is the more primitive, over-crowded society, Solaria is highly developed but becoming neurotically opposed to any social contact, and Aurora is a more balanced middle. Asimov later tied all of his future history into one big whole, and R. Daneel Olivaw becomes a character in the Foundation series.

1) '''We can't ever build a robot that will be even as good as a human being in anything that counts, let alone better. We can't create a robot with a sense of beauty or a sense of ethics or a sense of religion. There's no way we can raise a positronic brain one inch above the level of perfect materialism.
'We can't, damn it, we can't. Not as long as we don't understand what makes our own brains tick. Not as long as things exist that science can't measure. What is beauty, or goodness, or art, or love, or God? We're forever teetering on the brink of the unknowable, and trying to understand what can't be understood. It's what makes us men.
'A robot's brain must be finite or it can't be built. It must be calculated to the final decimal place so that it has an end. Jehoshaphat, what are you afraid of? A robot can look like Daneel, he can look like a god, and be no more human than a lump of wood is. Can't you see that?'''

2) ''It could not all have burst full-grown into his mind. Things did not work so. Somewhere, deep inside his unconscious, he had built a case, built it carefully and in detail, but had been brought up short by a single inconsistency. One inconsistency that could be neither jumped over, burrowed under, nor shunted aside. While that inconsistency existed, the case remained buried below his thoughts, beyond the reach of his conscious probing.
But the sentence had come; the inconsistency had vanished; the case was his.''