All food is killing. That mushroom that you pick dies earlier. Same for the lettuce, cabbage and carrots. Apparently there is a line somewhere near locomotion that says where to stop killing?
I see eating those as more akin to part of its sexual reproduction and continuation of life, like a bee taking nectar from a flower. As far as I understand it, Natural order works where a "food" matures, falls, and an "animal" eats it and passes its seeds through its digestive system. This process deposits the seeds in a fertilized position to grow its next generation. In a more poetic form, you can hear this in the Mahamrityunjaya Mantra[0,1] (Great Death-conquering Mantra), ~"...like a good gardener releases the cucumber from captivity (of its stem), free me from death but not from immortality."
That's true for fruits (in the botanical sense), not roots (carrots), fungi (mushrooms), or cabbage and lettuce. You're killing or injuring the organism and not helping perpetuate it in any way.
When a human harvests those organisms and replants their seeds among compost, it seems awfully similar to me. (Yes, I understand they each have some level of awareness similar to a mammal and bird. Here, we seem to focus on the meaning of killing. Perhaps our frame of reference which would call one yes and one no limits our ability to understand what happens in these processes.)
Tangent hidden in Mahamrityunjaya: If your unit of analysis of Life consists of one body of directly wired cells, then death for it would seem to occur when it stops nourishing itself or starts nourishing another body of directly wired cells. If on the other hand your unit of analysis for Life is Life, then replanting its seed is its continuation, afaict. This opens a paradox... If eating a head of lettuce seems fine while a new crop grows, then why not a head of cow while its calves grow too?
People can get trapped in their heads by paradoxes, so I like to go by my gut and my heart (don't worry, they're connected to my brain and they have a lot of neurons, see peripheral nervous system[0]) and econophysics[1](?linked document seems to have changed a lot). So, basically cold, hard calculation in a warm, soft body. If I can run my home on cow meat and feel good about it then bravo, but I can't for two reasons: 1) I love Life and want to maximize and respect it 2) eating cows is horrendously inefficient, for example you can get 6x as much meat from the same exact inputs of feed and water from meat rabbits.
Meat rabbit production seem like a very good investment right now and a potential focal point for planning my near-term food sources. They can also eat the grain stalks and inedible carrot leaves etc, and their poop works extremely well for compost. I want simply to figure out how to make the most of my available inputs, so if I can turn those green leaves into mushroom food instead and still grow enough grain while I use those stalks for construction projects etc, then great. We're talking about living here, so it's a matter of costs and benefits, right?.. what's Life worth?
None of those foods have seeds. You're not going to get anything out of the compost except rot. You're not helping them reproduce. The only maybe exception is mushrooms, since when they get plucked up you might spread spores.
Mushrooms are the fruiting body of a much larger fungal complex. Many fungi use the fact that animals carry the mushrooms (and their spores) off to eat as a reproductive strategy.
Let's assume a purely materialistic view of reality. In such a system all truths will be defined from nature.
1) Animals in nature kill each other all the time for food and sport.
2) All eating after a certain cell count for a creature requires death in some way.
3) Death is inevitable; life is not.
4) Force is the determinate factor for making something happen.
5) The universe does not care for life or death. It is merely a thing. It too will die taking all life within it with it.
Construct a moral set from those points (add more if necessary). I contend that you can't seat any ethics on it except might makes right. Anything other than that is merely a personal preference with no justification outside of the amount of force one can apply.
As a result I see no distinction between what is food and what is friend. It is merely personal preference. Sentience does not provide any actual force. It might cause your force to act, but it does not, in and of itself, mean anything.
To get out a head of it since it's been bandied about: cannibalism is impractical because it leads to the destruction of society when applied to the general population. I did not say it's wrong, for it is only death, which as we've seen is just part of nature. I say it makes commerce and society difficult if applied internally as well as outwardly. We, as a society, have a preference for this stability. We, as a group of actors, have the ability to force this view by our combined strength such as police and other law enforcement institutions.
Of course, you have a valid point. But what you're ultimately arguing against is any form of moral reasoning.
While I find the theoretical discussion of morality interesting, I'm far more driven by the practical discussions. People generally accept a moral axiom, explicitly or implicitly, something along the lines of "Harming other individuals unnecessarily is wrong". If that is the case, I'm going to argue for the consistent application of that principle, which is also where sentience enters the conversation. If they don't hold a similar moral axiom (which I've found is fairly rare), then I don't really have any ground to stand on in this debate. I'm certainly not equipped, if it's even possible, to make a moral argument from first principles.
Also, that cow's ancestors made our lives possible. Someone had to sow those amber waves of grain, and they needed help. If a human would look at a life giving animal and immediately a knife or a meat grinder comes to mind, then both need help. Perhaps some animals could step up to it, hopefully of the human kind.
