In the long run, there is nothing to stop intelligent agents from identifying the molecular signature of experience below hedonic zero and eliminatin… - David Pearce

The irrationality of the "appeal to Nature" is illustrated by a simple thought-experiment. Imagine, fancifully, if starvation, disease, parasitism, disembowelling, asphyxiation and being eaten alive were not endemic to the living world - or such miseries have already been abolished and replaced by an earthly paradise. Would anyone propose there is ethical case for (re)introducing them? Even proposing such a thought-experiment can sound faintly ridiculous.

Genes and culture have co-evolved. But crudely, natural selection "designed" male human primates to hunt nonhumans and build coalitions of other male human primates in order to wage territorial wars of aggression. Nature didn't design us to become a scientific community and collaborate to overcome aging. It's difficult to imagine that any human enemy could inflict such gruesome damage on the victims as growing old. The ravages of aging strike down combatants and civilians alike. So the trillions of dollars that humans currently spend on ways to harm and kill each other ("defence") would be more fruitfully spent on defeating our common enemy. We should work together to build a "Triple S" civilisation of superlongevity, superhappiness and superintelligence.

My own sense of how to behave in a simulation has more traditional roots in the theory of perception. I've long believed that each of us lives in an egocentric simulation of the world run by the mind/brain. Since the zombies of each (waking) simulation have sentient real world counterparts, one should treat them as though they were real. Nonetheless as an angst-ridden teenager, my dawning acceptance of an inferential realist theory of perception made me feel as if I'd been condemned to solitary confinement for life. The sense of loneliness was indescribable. Naïve realism is better for one's mental health.