I am quite familiar with the concept of living in "accord" with "nature". I found it alluring for a while, but it lost its luster, the more I studied our nature, and nature in general. Our nature is violent. All nature is violent. Even the tree aggressively seeks dominance over all contenders, spreading it's branches wide, and stunting them with its shade. Creatures don't seek some equitable station in their ecosystem, they seek to succeed. To propagate. Humans, with an understanding of morality, are unique in that they can control this impulse, if they choose.
And to be clear, even most of the "accord" philosophies acknowledge morality. They have lists of what is good and bad in a moral view. Buddhism is an example, having a concept of morality, and right and wrong thinking, actions, understanding...
You are correct, that people must be taught morality, just like they must be taught language. There is nothing detrimental to knowing there is a right and wrong. In fact, the lacking of one is what is detrimental.
Based on my studies, you have an inaccurate understanding of "accord" as well as Buddhism.
I'm not sure I'd say we are violent by nature, nor that nature is violent. The word "violence" connotes strong aggressive action that is not warranted. Therefore, an animal killing another animal for food is not violent, it is simply carrying the innate drive all animals have, to perpetuate its own species.
Life is precious - it is the ineffable, the transcendent, which means bigger than we are capable of explaining in words. From the first stirrings of human writing, we can see the puzzle, the wondering about this grand paradox that in order to live, other things must die. We eat dead plants and dead animals, those are all the food sources that exist. How can this be OK? The only explanation they came up with is that "life" is not my life and your life, but rather, all life put together. Which means each of us as individuals is a micro-part of Life, intentionally with a big L. Primitive humans, accepting this as a belief, would be conservative in their killing of animals for food - just enough for them to eat, survive, procreate. As a side note, since life was seen as the big deal, women were worshipped - it was obvious that new life came from woman, and a man's role was merely to provide a safe place for her to create life (give birth). Note that in these days, the creation of life itself was seen as risky, given what is estimated to be a 10% rate of other other or baby dying during the birthing process (same as other mammals) and another 20% for infant child mortality.
Surely we must eat, so Life cannot be upset by us eating by killing animals and plants - so humankind made stories up about this. The bear came into out midst because Life decided that bear's purpose was to help feed this tribe of humans...just as, if a human strayed too far and fed another animal species, it was something Life intended..or at least accepted. One way to make this mentally tolerable was to create the notion of an afterlife. This spring's bear would come back next year as next year's bear, and so on. This notion of afterlife and re-incarnation can be seen to evolve as religious beliefs changed over the eons, and can be seen in the Hindu and Buddhist beliefs in reincarnation, and to a lesser extent, the Christian belief in purgatory.
Buddhism does not tell you what is right or wrong. There is no explicit claim that specific acts are right or wrong. Rather, the way you lived your life is evaluated and when you die, you are reincarnated elsewhere - and it's a place for which you are ready. If you have led a life of theft and the taking of lives, you will spend your next lifetime having things stolen from you and your life taken repeatedly. If you have lived a life of being generous to others, then you will go to a place where others are generous to you. You spend as much time in each afterlife as you spent in your corporeal life, then you return as a human again. Ultimately, if you lead a 'perfect' life, which means you get rid of every desire you have - no fleshly desire to reproduce, no desire to eat because you have, in fact, shucked off your desire to even live - then you will not be reincarnated, but will become one with - nirvana or whatever their concept of it is. That is Buddhism as has been practiced since circa 500AD....this I gathered from my reading, my attendance at temples in Japan, and conversations with friends of mine in and from Japan. I am told, by my friends from India, that the same concept of reincarnating into a place you are prepared for is somewhat altered, but also exists in Hinduism. Over in China, Buddhism tends to be restricted to mountaintop villages, and in the cities, a form of Confuciousism (not sure if that's the word, but based on the original dude who came up with the idea - Confucious) is practiced. Confu-whatever is said, by my colleagues from and in China, to be kind of like Buddhism but made more practical: one is not encouraged to shuck off all worldly desires, but instead, to consider the impact of one's worldly desires on other people, animals, plants and "the world energy" which is generally interpreted as being wind, rain, fertile soil and sunlight. And yet again, one is encouraged to do theses things, and not told right versus wrong or you'll be punished.
Each of those cultures, of course, does have law enforcement and that is seen as the place for them to create "right" and "wrong" for the purpose of maintaining a peaceful society - nobody I've spoken to makes any claim that there's a 'moral' or 'ethical' imperative - you are not considered a 'bad person' if you break the law - you just did a bad thing. The crime rates in all those areas are much lower than in the Westernized world.
The other point on which I'm fairly certain evidence does not support your claim is this:
"Even the tree aggressively seeks dominance over all contenders, spreading it's branches wide, and stunting them with its shade. Creatures don't seek some equitable station in their ecosystem, they seek to succeed."
I live in the country and have for a long time. The only naturally-occurring tree, still growing in its natural habitat, that chokes out everything as you say, to my knowledge, is the redwood. That tree is so acidic, nothing else can grow in the soil beneath it. In even the largest redwood groves in Northern California, there is plenty of sunlight at the base of the trees. And - the amazing thing about redwoods is that they are so tall that they cannot get water from their roots - capillary action can only carry water so high. Therefore, they can get proper water only from fog - which is why they grow natively in places where there is daily fog year-round. Young trees can and do get water from the soil, and that's exactly how young redwood saplings get their water...the big trees don't stop that, nor do they block the sunlight.
Up here in Oregon, we have some old growth forests and it's amazing how well the plants co-habitate. A tree growing in a place where ther'es a lot of underbrush won't grow so large...even as the underbrush pulls back to let in the new neighbor. We also have a non-native species, the Himalayan Blackberry. Having grown in high altitude arid climes with mountain goats, it had to develop an agreesive manner of keeping itself alive and that is that it procreates vigorously. In its native habitat there were no other plants, so it had no need to share. Bring it to watery Oregon sans mountain goats, and this plant grows 50 feet in a year and will, indeed, suck up all the water and kill an entire forest in a few years, by depriving the trees of water. But this has been allowed to happen only due to the interference of humankind.
Where I live is a mixture of farmland and timber. While we don't have a neighborhood association or covenants and all that stuff, we do believe we depend on each other. Everybody knows who can fix electric fences, who can sharpen saws, who can fix small electronics, who can help you figure out which critter is eating your veggie garden. We gather at one of two watering holes known as taverns, and there are 3-4 neighborhood festivals, celebrating planting or harvest or in one case, the Swiss culture, since it had a lot to do with populating this region. In a 10 X 10 mile area, we might have 200 total families, which is about what you find in the average suburb of two blocks. Lots of open land.
In this area, we have lots of free-range deer, lots of coyotes, an elk herd and one cougar. The cougar takes down an elk from time to time...she seems to be satisfied with one elk for most of a month. She might go after a coyote, if one has gotten old and weak and strayed from the pack. The Coyotes, meanwhile, consume small critters - rabbits, mice, that sort of thing - but they don't eat all of them, as the coyotes seem to have some idea of territory and want to stay right here. They do not leave the area seeking out even more food so as to procreate more...they seem to have some notion of statis and some kind of awarness that as long as they don't eat everything they can, then there will still be plenty more brand new critters to eat next year. Coyotes are, in fact, omnivores, so if there isn't enough fresh meat around, such as in winter, they get by eating field grasses - and I've never seen them consume an entire field. In fact, they seem to eat in patches, leaving just the right amount of grasses that next season, the fields fill in again.
The only animal I know of that will consume the entirety of anything is human. In fact, if we encounter something that stops us from growing without limit, we come up with a medical fix. We built houses so we don't have to worry about fending off predators, we've come up with ways to avoid infant mortality, we figure out ways for babies born with bad defects to make it to adulthood and create more babies with birth defects. All told, as a species, this weakens us considerably. If, in fact, human ran out of oil energy, the human who survive would be the aboriginal cultures, because they're living without it anyway. It's us Westerners who'd perish without thermostatically-controlled temperatures.
Now I'm not about to say we should let unhealty babies die...but I am a realist and I am aware of what our species is doing to itself, and we are NOT perpetuating ourselves.
And...we gather in such dense populations that we increase the spread of infectious disease to a point where we must innoculate - no other animal species does that, and none are at risk of losing a large number of their population due to any disease spreading.
The socieities we've created are artificial, and there is no way our natural selves could figure out how to live in them, so we must create rules and laws to avoid anarchy. Is it moral or ethical to obey those rules? Or just common sense, a mere appeal to the desire to remain alive?
Morals and ethics are geographically-dependent and also dependent on the wealth of the society. In the US, we would be shocked to have public restrooms that allow either gender. And yet I've been places where they exist - without stall walls. In the US, we are also acclimated to houses that are ridiculously huge compared to most of the world. Even in cultures we don't think of as all that backwards, having Mom, Dad and kids of both genders sharing a bed - not just a room - is common. I have been in places where the morning community shower and dressing room was both genders. The luxury of having separate quarters does have a financial cost - we Americans don't realize just how luxurious our lives are!
There are countries that consider themselves Christian where it is allowed for each man to have four wives...why? Medical science not equal to the US, high infant mortality, high rates of women dying in childbirth, and men going off to war so often that the ability to create a child is rare - these countries are keeping their population levels stable, not growing, by this encouragement of procreation. Are they immoral because they practice what we would call bigamy?
There are few universal morals. My own opinion is that the exhortion to not murder (aka unjustified killing) may well be one of them. I'd like to think so.
But I've been enough places, and seen enough differences in levels of resources available, to not think that most morals are, in fact, universal...with 7 billion people on the planet, there's a whole lot of variation and it's unlikely to find any rule that works for every place on the planet.