"There is no way we can raise a positronic brain one inch above the level of perfect materialism... 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."
- Lije Baley (Caves of Steel)