There’s an interpretation of the Adam and Eve allegory that I like, though I note that I'm not Christian.
Being naked humans in the natural setting of the garden, and eating from the tree of knowledge of good and evil, Adam and Eve realize their nakedness and thereby become distinct from the rest of the natural creatures. Squirrels are natural (i.e. of nature). Cats, dogs, fish, and all the rest are natural. By this I mean that we can observe these animals and come up with more-or-less unwavering templates for what natural behaviour looks like (mating rituals, vocalizations, sleep habits… whatever). It is natural for a carnivore to prey on other animals, and neither partner in this relationship has a choice in the matter. The carnivore’s body requires the nutrition of other animals and cannot survive otherwise. Likewise, the prey is stuck in a biological station that occasionally demands payment for existence.
There’s nothing humans can do about any of that.
Back to Adam and Eve. Eating the knowledge-apple has the effect of making them aware that they are standing naked in a natural world. They are no longer animals within that world because this “original sin” gives them too much mental capacity to be subjected to the instinct-driven autopilot existence that we see in animals, and what's more we’re left with the inclination to make judgements of rightness and wrongness. We might think of this as symbolizing a critical spark of intelligence that separated man from some earlier hominid in our evolutionary history. No longer a part of the instinct-driven fauna, we are forced to draw our own conclusions about the correct ways to act in all situations. If we see a squirrel eating an acorn we can call that right behavior for the squirrel, because we know that squirrels don’t, for example, eat birds. And there are countless other behaviours that are either right or wrong for squirrels to be doing. We’re not like that ourselves though. It is our born-into condition that we must draw our own conclusions about correct and incorrect behaviour for every action, and this is what human culture comes from. Even if we decide to defer decisions to some higher power, all the specific applications of our morals and how they should be applied (e.g., don’t lie, don’t kill) are left to us, and the gray areas are easy to get lost in. Should we lie to spare an other's feelings? Can we kill to defend ourselves? This awareness of ourselves and the consequences of our actions is the uncrossable gap between us and the animal world. Humans are unnatural creatures in a natural setting. The incredible gift of our human intelligence comes at the price of having to use it critically and often not having binary answers to seemingly clear questions. To not use this intelligence may in fact be the only truly incorrect behaviour humans are capable of. We’re not animals.
Now comes an interesting question. Is the “correct” behavior for humans to eat meat or not? There are, as I see it, two stances to take. One is to point to the animal kingdom and to recognize that ingesting animals is common, necessary, and natural, and while we may be aware that this inflicts suffering on our prey, it is nonetheless the way of things. The other stance says that the same human intelligence that lets us (a) ask the question to begin with and (b) assess nutritional intake, has simultaneously provided the science which points us to non-animal sources of all of the nutrients that a vegetarian diet would otherwise miss, so we can’t claim ignorance; we know that we don’t need meat to be healthy. Acknowledging that the world is a cruel place and that the animal kingdom is subject to the pervasive suffering of the predator-prey relationship, shouldn’t we have the maturity to not contribute to that suffering unnecessarily? We can’t take the examples of the animal kingdom as a license to kill, because unlike animals, we’re not bound to an instinct-driven mode of existence. We’re outside of it.
At this time, modern nutritional science seems to say that a healthy diet can either include or not include meat, although a meat-free diet should probably include certain nutritional supplements (NOTE that this does not, believe it or not, include protein). Having been divorced from the automatic morals of the animal kingdom by our intelligence, discovering via science what nutrients we need (an ongoing process), and also learning how to synthesize nutrients we habitually lack, it almost seems as though the universe is telling us the answer just by giving us the ability to think it.
This awareness that we’re uniquely self-directed beings in an otherwise instinct-driven world applies to much more than the question of vegetarianism. Whether or not we’re aware of it, we’ve been taking control of our evolutionary direction out of nature’s hands for a long time. Eyeglasses allow genetic traits to pass on that, at an earlier point in history, would have been selected out by an inability to hunt and/or gather effectively. Medical advancements mean that we can now pass on all sorts of traits that would be detrimental in a pre-technological age. Modern humans can expect to live more than twice as long as our ancestors from about 500 years ago, in part thanks to better life-enhancing or healing chemicals (medicines) and bio-enhancing implants (pacemakers, cochlear implants, etc.) Whatever natural evolutionary path we would have taken is being prevented, and that’s OK. Perhaps the right thing once a species gets to this point is to embrace the control we’re developing over our own destiny, and perhaps the new self-induced stage of evolution that we’re now entering is just as valid as the one that nature applies to the animal kingdom. What I’m saying is, considering that we have the gift of these self-directed brains, perhaps the correct thing to do is to embrace it and go whole hog.
Transhumanism is the philosophy that the current limitations of the human condition (like lifespan, but not limited to this) can be overcome by science and technology. It’s the idea that science-driven self improvement is in fact the next natural phase of our evolution. Meditation or spiritual growth may be important, and for some these can be primary paths, but this shouldn’t preclude parallel advancement in the mundane world via science. If people could reasonably expect to live long enough to fully appreciate the concepts of their respective philosophies/religions, then all the better, whether this means living to eighty or eight-hundred.
Luckily, finally, there’s real scientific attention being paid to improving human longevity now. What’s somewhat frustrating is the mentality that this might be a bad thing.
Google’s Calico is working on this, for example, although it’s been criticized as a self-serving bid by Silicon Valley’s elite to live forever. If it takes a small group of billionaires to finally give this topic the attention it deserves, then so be it! Clearly the average human doesn’t have the vision to push for this kind of development, and even within the medical community longevity research had persisted on the fringes of the mainstream until more recently. It's also a wonderful thing that we now have the tools of CRISPR at our disposal and that non-mainstream scientific communities (like biohackers) are starting to experiment in these regards. Josiah Zayner and his ilk are heroes. However it comes about, we need the research to happen. Detractors point out potential issues with social equity involving overpopulation and increasing class disparity if people live too long. We should be happy, they feel, to get the 80 or so years that we do. Fools. If we place these same voices in Classical Rome, surely they would have lambasted anyone claiming that humans should some day attain to 80-year lifespans. No modern octogenarians seem to think we should surrender our hard-won longevity based on principle, or some ignorant conception that daring to consider longer lifespans is a violation of a natural order. Thanks to our incredible self-directed brains we can be and become whatever we choose, and this is right to continue our evolution. If the average human lifespan some day increases to 200, we can probably expect an entirely new depth of insight from our artists, musicians, and thinkers of every stripe. We would also expect those people to look back on the previous relatively short-lived generations with the same detached pity we reserve for our own ancestors’ lifespans. We should be pushing ourselves to this kind of improvement. If we don’t, we’re wasting our special brains.
Every human that’s ever existed has had a terrible disadvantage in terms of historical perspective. We’ve been allowed to glimpse only a sliver of the whole of human progress, and the same mistakes get made generation after generation. Our culture may have advanced, but each new human has to trudge up the mountain of understanding from scratch. By increasing the human lifespan, or possibly by encoding new instinctual knowledge into our genes, this lack of perspective can be made to crumble. The social imperative to be kind to each other and to pull up those that are less fortunate would become more apparent, not less. As well, the societal ills of consumerism would, I expect, begin to be seen as the never-ending and unsatisfying satiation of novelty that they are. Surely, obsessing over the trivial changes in the latest model smartphone will get old to anyone who’s been subjected to it for more than ten or so decades. Humanity could finally start learning to take less than it gives, and start to cultivate responsibility for the extremely long-term future, leaving behind the “it’s the next generation’s problem” mentality. It would also have the time to expand into the stars.
Even if one isn’t prone to optimistic predictions of the future, it is good to keep in mind the visionless speculation that had been applied to the personal computer, the steam engine, early surgical technology, and so on in the early days of those technologies. Just stop it. Let’s support the improvement of life and longevity. It will be good.