@Pyro: At work with limited internet at the moment so I can't reply to most of this stuff, but the one thing I wanted to quickly comment on: Empathy is not an ideal, it is an instinct separate and distinct. Same goes for sympathy. These are things most social creatures possess, especially pack-based ones (ex: tribal humans).

The reason this is important to note is because it paves the way for the formation of morality when combined with a sufficient level of intellect. This is why our morals have evolved over time and become more expansive, comprehensive, and complex.

It's also because you are certainly correct about some humans possessing limited or completely vacant empathy and/or sympathy. This is typically due to a mental disorder, though. As well, our intellect makes us capable of overriding base natures, like empathy. Ex: Soldiers being trained to kill.