The universe forces those who live in it to understand it.
How smart does a chimpanzee have to be before killing him constitutes murder?
The universe is a pretty big place. If it's just us, seems like an awful waste of space.
Not all bits have equal value.
Who are we, if not measured by our impact on others? That’s who we are! We’re not who we say we are, we’re not who we want to be - we are the sum of the influence and impact that we have, in our lives, on others.
The Platonists and their Christian successors held the peculiar notion that the Earth was tainted and somehow nasty, while the heavens were perfect and divine. The fundamental idea that the Earth is a planet, that we are citizens of the Universe, was rejected and forgotten.