Consciousness?
Sentience?
advanced cognition?

Morality?
Advanced communication skills?
Physical dexterity?
Highly adaptable?

Or is it the ability to recognizes our obligation to all of life on earth as stewards of it? That separates us from animals. All animals exist for is daily survival, and for them there is no connection to history or the future. Man does recognize these things, and is cursed with it. Not only the realization of our own mortality, but the mortality of the universe itself.

We are the universe witnessing it's own existence, and all possibilities that could arise from it.

Deep shit.