Let's meat in the middle and accept that it is to each their own on what we eat.
It's not comparing apples with apples. Slavery, witch trials and apartheid never constituted factors which involved life or death for humans, in that humans starved to death if they did not burn witches, keep slaves or maintain apartheid.
We were not designed to be slaves or to be held in slavery; we were not designed to be burned as witches or defined as witches; we were not designed to separate ourselves racially.
We were designed, as human beings, to eat pretty much anything, including meat.
What I would like a vegan to explain is how would we manage the situation where no animals, were ever killed for food again?
Would we set up reserves and return them to the wild? Would we have to kill some, a half or more because there would not be enough land for them all?
Who would pay to monitor, manage and maintain the reserves? When breeding reached optimal levels, beyond which they would graze out the area and begin to starve to death, would we cull? As in, kill?
Would we leave cows, sheep, goats,chickens, pigs, domesticated for thousands of years, to die in agony, over days, if they were injured or sick in a way which would never happen to an animal farm-raised? And if not, who is going to pay for the vets?
I personally find the selective approach to the sacred nature of life to be convenient and erroneous - plants have feelings and carrots feel when they die to keep us alive, just as cows do. The core issue is not eating a cow, carrot or crow for that matter, but how graciously, sensitively and humanely we treat them while they are alive and in the nature of their dying.
Humans are omnivores and that means we eat absolutely everything. I would be prepared to bet most if not all Vegans and Vegetarians, living comfortably as they do in the developed world, would be out there killing with the best of them if they faced famine or starvation as some still do in the Third World.
When their children were starving the question would not be, 'will I feed them this grass,' actually grass kills more often than not, or 'keep them going with a handful of berries,' but can I catch that mouse, rat, bird or fish to feed them, because the meat will give them more strength and nourishment and vastly increase their chances of surviving?
I am continually struck by the ironing, living in Africa as I do, that in the Third World people do not agonise over what they will eat but IF they will eat. Sure, Hindu Indians have less options but they get protein from weevils and insects in the foods that they eat which no doubt help to keep them alive.
Being vegetarian has never been a human choice except when dictated by religion. In other words, vegetarianism in all its forms is a choice which, while it may not be rational or sensible, certainly not in this day and age, is dictated by religious belief and it is very clear that a lot of religious belief is not only irrational it is nonsensical.
Everything feels, carrot or cow. As humans with higher capacity, generally, to think and reason, we have a responsibility to carrot and cow to ensure they have quality lives before they die to keep us alive.
It is pure conjecture and I would add, arrogance, to assume that a cow has more feelings than a carrot. All is sacred and deserving of respect.
The fact is, humans will eat whatever is available in order to survive, and as history records, people have eaten other humans to stay alive. Some cultures were actively cannibalistic, including their own children like Australian Aborigines, even when they were not starving. Many cultures in ancient times had various practices for consuming all or part of enemies killed in battle. Some had practices of consuming flesh and organs from the bodies of those they had respected in life and now honoured in death.
Humans are omnivores and they evolved to eat anything they needed. Given how difficult it is to catch game one presumes that if other foods were plentiful, this would be a last resource. Or, one presumes, having eaten meat they came to understand it made them stronger and healthier. And they liked the taste, hence the effort was made to include meat in the diet.
But humans have eaten and would eat other humans to survive. They just do not need to do so. The next meat source is animals.
And animals eat animals and birds eat animals and birds and fish eat each other and so it goes - it is just a way of life and a bee eating what a bee eats, although I gather fundamentalist Vegans won't touch honey either, is no better than a lion eating what a lion eats.
Anyone who has ever been on safari can observe the 'agreement' reached between killer and victim and have an understanding that the nature of this world is that death brings life and whether the death is of a pig or a potato, makes no difference.
People like the Canadian Inuit would never have survived if they had not eaten meat, their diet being largely whale, seal meat and blubber. No plants to be found in the arctic beyond seaweed and clearly that was not enough.
I think it is absolutely fine for people to come up with diets which suit them and where they feel content in regard to the food they consume, but when they morph into religions or fanaticism where eating a piece of meat, is seen to equate with hiring a slave, burning someone at the stake, or setting up an apartheid State, it is simply ridiculous.
As someone who appreciates and enjoys all the food available on this bountiful planet, but who believes completely in humane food production practices, I find the Vegan/Vegetarian campaign against meat-eating to be pompous, patronising and increasingly pathetic.
Go chew on your carrot sticks and leave the omnivores alone, and remember, just because you cannot hear your carrot 'scream' does not mean it is without feelings!