Where is the proof that other animals, let alone other humans, possess sentience, and that their behavior patterns and/or EEG results are not wholly instinctual patterns/responses? Different types of people have different types of neurons and slightly different brain structures, and certainly “animal” species differ in that way from humans and from one another. Why do trees', or plants’, slower form of consciousness, or non-neuron-based existence, or whatever you’d call it, make them unworthy of the self-determined life, while animals’ comparatively faster perceptions, or “more like us” brain structures, make them more worthy?
Should we slaughter a cornfield to spare a bovine? Eliminate an acre of soy to preserve a redwood? What makes one better than the other?
I know and understand said difference, and in another way, I "know" why soy is different from redwoods and preschoolers, too--the way we all do, in the sense that we've accepted a perceptual normative from the perspective of our biological and cultural wishful self-immanence: exactly the type of behavior we're supposed to put behind us as potential correct-believers.
Any belief system based upon killing one type of structure, and not another, is, unless derived wholly from openly selfish reasons--taste; admittedly-subjective feelings; or, material health rationales, whether incorrect or correct--necessarily a religion, and a clumsy one, in the sense that it claims or undertakes to provide the sole definitive existential answers. Although occasionally more vitriolic and arrogant, and occasionally more giving and modest, plant-based or solely-plant consumption systems with the tiniest scrap of morality are making profound judgments about the weight and value of self, other, part, and whole; about soul, creation, and meaning. A willful epistemological blindness characterizes such viewpoints, for unlike the prominent token modern religions, the morality of any given plant-slaying belief system--say, "veganism"--does not offer itself as an advocate for neuronic superiority, but rather, presumes that we've already accepted the faith of neuronic superiority--or perceived-sentient superiority, vertebrate superiority, or locomotive superiority--and makes its case from there. Personificationist deists, at least, tend to vest their offerings, requests, and/or demands in the presumed power and omnipresence of one or more deities, offering an origin narrative which, if true, might justify such offerings, requests, and/or demands. The "neurons make me special" crowd, by contrast, takes it for granted that you already agree with them.
"Don't eat meat because it's wrong to kill animals" is a value judgment more decisive and random than "Men shall not lie with men." In either case, "Because it offends an all-powerful entity" is a justification which itself requires a normative framework, but the latter prohibition against male homosexuality admittedly rationalizes itself through subscription to the unproven and/or unprovable. The intellectual superiority of one who acknowledges one's supra-intellectual, willfully non-investigative claims, versus one who deceives oneself about being a rationalist, is profound; ergo, we see many dumb Christians being, in truth, more intelligent and honest than many a progressive opinionist. Those who make the "wrong to kill animals" argument without citing a supernatural force, and a concurrent belief in the unobservability or falsifiability of said force or the reasons why we are its subjects, experience an unpleasant dissonance at the thought of justifying their morality. Plant-denialists may argue that killing free-range all-natural chickens for consumption is always wrong, while killing factory-farmed lentils for consumption is always right, a distinction that requires a massive expenditure of faith. The save "everyone agrees that suffering is wrong" is ineffective, even if everyone did feel that way, for a bovine which exerts little-to-no effort, sleeps whenever it wants and stuffs itself with food whenever it wants--or, conversely, dwells in an organic grass range with its loving family and friends--and is then killed painlessly with no forewarning--still does not satisfy plant-denialists. They find, upon approach, that they must and do have other reasons, specifically latent Judeo-Christian traditions regarding the importance Yahweh/Christ vests in the soul, for their beliefs. For acknowledged WASPs and other Christians, this is a comforting overlap, whereas for pseudo-militant queer vegan online activists, it threatens to raise troubling thoughts from the cellar of the mind.
Today's belief systems, of whatever form, would be well-advised to develop more thorough origin stories, namely, ones injected with structural justifications for desired behavior. Fostering nihilism among the people is all poor and bad, but sustained philosophies of any kind--black lives matter; fat acceptance; polyamorous transsexual adoptions; anything which is expressly not nihilism--require more. The staying power of the Torah and its successors has been the composite panelboarding of Nun, Atum, Osiris et. al. into the varying originative or justificatory narratives explaining why it was consistently important to care about, e.g., getting up in the morning and/or genital placement. The Big Bang Entropy and Big Bang Cold Death doomsday cults work well at dissembling things, but, without an essentially Judeo-Christian mythos from which to draw, will perform badly at guiding behavior over the long term. Next century's people, farther removed from the residual cultural value of the soul, and its correspondingly sentient capacity for free will, will care less about animal rights, sexual consent, or space exploration, absent a non-nihilistic, even if stupid, normative inside which to rationalize reasons.
Given the Bank's interest in some degree of perpetuation, we should see over the next century or two the fiat creationist Big Bang be more coherently reindoctrinated into the Torah--not as a mere re-expression of Genesis, but more modern, sparkling, and rewritten. In short, a Reformation is in order: some manner of faux resistance to the soulless age, which reaffirms itself by clarifying its updated acceptance of the tradition humans think is their tradition (e.g., Genesis/Big Bang, followed by Cold Death/Rapture), but discarding some token non-structural elements to make us think, like a good election or revolution, that things are fundamentally different. What will be the new religion? What barely glimpsed godform will justify correct behavior before death?