Please note that I have excluded the lengthy scriptural quotations from my response to the OP’s question, which I have taken from an essay that I wrote in answer to this question, published on Medium.com here: Why Is It Necessary To Not Eat Meat?
It seems as if the eating of animal flesh is a flashpoint between the Buddha’s message and the desire of many Buddhists, even many ordained Buddhists, to eat the flesh of animals.
But the Buddha was clear that to eat meat is to abandon his teaching about compassion, to ensure a continued attraction to the lower realms of being for oneself, and to block the possibility of becoming enlightened, leaving ultimate freedom forever out of reach. Could this be the answer to why so few buddhists reach enlightenment nowadays?
Many buddhists seem to be playing fast and loose with the Buddha’s instructions to ordained sangha, who were dependent upon the charity of householders for their daily meal, specifying when it would carry no karmic danger for them to eat proffered alms consisting of animal flesh. His instructions were directed at a particular context which is rarely found in the modern world, and certainly not in Western countries where the tradition of begging for alms never existed and modern ordained sangha shop for their food.
Applying the exceptions given in the Buddha’s threefold contextual allowance for eating meat, given only to ordained sangha who were begging for their food thousands of years ago, to purchasing meat from the frozen food aisle in modern day supermarkets is, in my heart, the height of sophistry—using clever and false arguments to cover for one’s failings, and by so doing, leading others astray.
Eating meat is inconsistent with Buddha’s clear call for compassion for all sentient beings. Why else would he have gone to the trouble to delineate the cases where it wouldn’t cause a problem in the limited contexts existing during the time, and within the traditions, when he was teaching in the world. Obviously, he was making exceptions to his general prohibition against eating animal flesh.
Using the argument that it is ok to eat animal flesh so long as you have no direct involvement in the killing of the animal—in today’s context—is a fainthearted attempt to escape one’s weakness in following the Dharma, and culpability in providing a market for such murdered flesh. Without a willing buyer, there would be no killing. This is simple economics. It doesn’t matter who puts the words in the Buddha’s mouth, he never said that you, today, could eat meat without suffering the consequences of your culpability for the suffering of those animals.
Modern practices of killing animals are much worse than those in the past. Animals must stand by the hundreds in concentration camps, euphemistically called ‘feed lots’, for days, in the stench of death of their fellows, listening to the cries of horror at their fate, until their own time comes, some so sick and unable to walk, they must be bulldozed to the killing sheds.
And should we overlook the damage that is done to the Earth in order to raise the billions and billions of animals slaughtered for their flesh each year? Science is clear that the majority of the destructive gases filling our atmosphere, causing the Earth to heat up to a point where little life will remain, is due directly to our fashionable diet of dead flesh. So too is the mass destruction of wildlife habitat that is the necessary condition for global pandemics to emerge.
Eating flesh is incoherent with being Buddhist. The behavior most in tune with the Buddha’s message of compassion towards all sentient beings, and the end of suffering that was his heartfelt intent for all beings, is to never eat the flesh of animals.
As a Buddhist, one should also adhere to the doctrine of causes and conditions, and realize that eating the flesh of animals creates the possibility for a profitable demand for animal flesh in those of weak mind who are unconcerned about profiting from the suffering of others for their own benefit. By eating animal flesh, you may feel that you are not directly responsible for the animal’s death, but by creating the condition for someone of weak mind and strongly selfish desires to cause harm to others, you are responsible for leading them astray. You may try to abdicate your responsibility to protect the weak and voiceless, but you cannot escape responsibility for the actions of others that harm animals to provide you with meat. It is your actions that lead them, through their weakness, to the hell realms.