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.''