Morality of killing animals and plants

Hi, I’m not a vegitarian, but have been considering vegitarianism for the past year. I generally don’t eat much meat for health and environmental reasons, but ethical reasons are the ones that would make me give it up completely, and I haven’t been persuaded as I want to. I do agree that slaughterhouses and mass production of meat is disturbing, but I want to start from the ground up, on killing any animal.

We don’t want to kill another human. The reason? Empathy. We know what it’s like to be human, and we imagine, accurately or not, the thoughts and emotions of the other human, with relative ease. We assume that they are like us, which makes this so easy, and so powerful. How could we kill someone who feels the pain we do?
The standard argument is that animals also feel pain, love etc. They do, but it varies from species to species. Most humans wouldn’t want to eat monkeys, because we know that they’re human-like. Some animals, like chickens, have considerably different and simpler emotional and nervous systems. You say it’s wrong to eat them.
Plants have no nervous system per say, but they do react to their environments. They are lifeforms. So vegitarians qualify that it’s ok to kill lifeforms of some sorts, specifically, those that don’t feel pain, as we understand it.
What about sponges? A sponge is an animal. It has no central nervous system, doesn’t raise its young, doesn’t move around, and is basically a plant. But it’s an animal. If they were tasty or nutritous, would it be immoral to eat them? I don’t see why.

So the presense of a centralized nervous system is where I would draw a line.
What exactly is a nervous system though? It’s a reaction system, a bit more advanced than plants. Plants have system of chemical reactions that directly alter their behavior (grow more on this side, grow away from that mean rock), and animals keep more of the rules in one centralized place which sends out commands. Is it ok to kill a lifeform that uses one system, but not the other?

Perhaps it’s the emotions that make it wrong to eat animals. But.
Not all animals have emotions. Emotions are, again, another response system, an amazing and complex one that deals largely with social interactions (remember, plants have mating systems as well, and some have systems of cooperation and competition amonst themselves). So what makes animal “emotions” so special? So different? Do we have a preference for animals that use neurons, and modify their behavior with neurotransmitters for social rules? Or do we just sympathize with those animals who are very human? Does a fish love? Not as a human does, no. Fish are closer emotionally to plants than to humans.

Plants and animals alike have a purpose, to exist. I would argue different things about human existance, but that’s a very different topic. Why do we draw the dividing lines where we do on plants and animals? I’m considering only giving up mammals, who are emotionally most like us. But why there? Why not draw the line as close as not eating primates, or as far as not eating any multicellular organisms at all?

Any thoughts?

First of all when we eat plants we don’t always kill them.
Most of the time we eat fruits and vegetables…
many plants have ellaborated their own means of spreading their kind by offering something in exchange for this. These are usually fruits which are tasty and nutritious and do not involve eating the seeds.

Now where I draw the line… I do it where I suppose that pain is not inflicted to my food before I eat it. :slight_smile: