Also disclaimed: I eat meat without guilt but I've been talking myself out of just about everything lately.
What if the ultimate, pristine understandings of the Non-Aggression Principle (NAP) not only applies to all life but to anything that was ever alive? Where you couldn't harvest crops or slaughter animals and would need to either adopt an ethic that does not feature starvation or secure an inorganic fuel for your body. And what is that substance?
Strictly speaking, you'd also have to drink water that does not contain life immoral for you to consume. You can't boil the water because that would kill sovereign organisms. You need water that is somehow pure of all life. Extensively filtered? Organisms effectively evicted? Just like an evicted (as opposed to aborted) baby, organisms in the water have been displaced from their original vessel without harm. But what could you possibly eat except the bodies of dead plants and animals? Maybe that substance, if it exists, is the closest to the fountain of youth in Nature. Maybe even the cure for cancer. Cancer in this case directly tied somehow to the consumption of organic or once-conscious material. If the Non-Aggression Principle applies to all life in this manner, then libertarianism is actually the cure for cancer and we are doomed until that substance is yanked from the universe.
Could we survive off water and vitamins alone? Must we consume some amount of plant or animal life? I started to make a pretty good case to myself for some variation of the vegan diet being necessary but even that is not strict enough. Assuming for this rabbit-hole that eating organic material is definitely a source of cancer, then why would that be? If all plant and animal life is sacred then consuming any such life would be cannibalism. If doing so results in cancer it seems Nature does not approve. Cancer might be Nature's kill-switch to prevent any of its constituent parts from consuming or becoming the whole. The poison released by one kill or salad may not be fatal but such 'violations' will culminate in the defense of all remaining life against that particular predator.
Another way to look at the NAP applied in this way is that cancer-causing elements in the deceased could vary based on the manner of death. Where a pig enduring the stress of a slaughterhouse releases more of the poison into its body than a pig who gets a surprise bolt through its skull. That pig didn't panic; it was chewing its slop and never knew an instant of fear. Free range chickens never knowing the stress of a hatchery would offer less of a cumulative cancer risk; their minds have not flooded their bodies with additional toxins. Looking at it this way, Nature wouldn't seem to be looking to punish violations of life as much as punishing prolonged stress or torment.
Nature: Consume life to sustain yourself if you must; I have ensured you do not do so in perpetuity and that every moment of fear, panic, and confusion in your prey is more poisonous than the last.
Consistent with this: humans suffering Post-Traumatic Stress (PTS) would be less desirable meals for the health-conscious human cannibal. As if life's ultimate defense is postmortem. The especially cruel cause their prey to be proportionately more toxic or maybe less delicious. Maybe a lion sneaks up on a sleeping gazelle and notices an improved flavor over yesterday's gazelle caught after a prolonged chase. I can't help but think of that drawing of a frog in a bird's beak but the frog's hands are outside choking the bird. I'd feel silly saying hunter-gatherers behaved immorally but could live suggesting they may not have had sufficient technology.
Editor's Note: This was a Twitter rant and has been edited.