@FatherJackHackettsUnderpantsHamper
Even if you don't object to killing any living things without a brain for food, that still doesn't answer the question of how you ensure that no animals have died in the production of your food - chiefly those killed by pesticides and combined harvesters. How many vegans are strict about only buying food - with the significantly increased costs, of course - from producers that use no pesticides and carefully reap the harvest by hand?
I know that animals will unfortunately die in the process of harvesting crops that I eat. Unfortunately, I have to eat something.
When there is mass production of animals for food, profit becomes priority and welfare standards begin to slip. If you think about the amount of land animals that are killed each year for food, and then think about the food that they eat, more animals are going to be killed in order to feed what you are eating.
Even if I did eat meat, I would still eat plants, so, I'd be responsible for not only the killing of animals whilst crops are harvested, but also the animals that are slaughtered so that I could eat meat.
If I presented you with a tomato plant and a cow, and gave you the option of pulling a tomato from the stem, or stunning a cow in the head and then processing it for food, which would you choose? I know which I would choose, and therefore I no longer expect anyone else to do something that I could never do myself.
I made a decision, not just based on the fact that I always felt guilt when eating meat, but also on the science. I know that many animals that we consume have brains, CNS and nociceptors, therefore they are able to feel pain just like we do - they may not be able to express it like we do, but they certainly feel pain. They are able to establish relationships and communities, just like we do. They feel and they suffer, just like we do.
I haven't eaten an animal, or anything produced by an animal in over 6 years. I'm not declining in health and so know I don't need to eat animals or their produce.