Do you see us slavering for revenge, that most pointlessly biological of imperatives? - Alastair Reynolds

But make no mistake. My counterpart is capable of a great deal of ruthlessness in pursuit of a just cause. He believes he has right on his side. And men who think they have right on their side are always the most dangerous sort.

All of it is physics, though, whether you are studying starlings or quarks.

The world had absorbed the dizzying lessons of modern science easily enough, hadn’t it? Reality was a trick of cognition, an illusion woven by the brain. Beneath the apparently solid skin of the world lay a fizzing unreality of quantum mechanics, playing out on a warped and surreal Salvador Dali landscape. Ghost worlds peeled away from the present with every decision. The universe itself would one day simmer down to absolute entropic stasis, the absolute and literal end of time itself. No action, no memory of an action, no trace of a memory, could endure for ever. Every human deed, from the smallest kindness to the grandest artistic achievement, was ultimately pointless.
But it wasn’t as if people went around thinking about that when they had lovers to meet, menus to choose from, birthdays to remember. The humdrum concerns of normal life trumped the miraculous every time.…And the knowledge that humanity was not alone in the universe would be as relevant to most as the knowledge that protons were built of quarks.