(Another post found languishing--from last November. Probably intended to wax more verbosely; I shan't.)
Those who've wrestled with ethics are aware that it's not a simple or easy topic. Even in the abstract it's slippery. Applied to reality, it seems like the best rule is that if it seems clear cut and obvious, it's probably not.
The challenge of eating ethically means that one's first got to decide what ethical means and includes in this case. And one needs to be wary of the notion that perhaps there's One True Ethical Answer.
My own answer is that ethics means you do the best you can, based on the information available to you when you have to make a decision. "Can" needs to be monitored closely, lest it become an excuse for laziness--it refers to ability, not to feeling like it.
I know others who are engaged with the issue of ethical eating. I have vegan and vegetarian friends and colleagues who either do--or do not--try to push their dietary beliefs. A few may be eating what they are for religious reasons, and others for health reasons, and some simply because they find eating meat icky (my beloved used to work with a vegetarian woman who chain-smoked, lived in a dome house, married a Marine, and disliked vegetables. I don't assume I know why people do most things that they do, usually. Often, our answers are complex and nuanced, even to ourselves). Most do so for ethical reasons.
I know people who eat... according to all kinds of rules. Some who are gluten intolerant, some who are allergic to some food or another (or several). Myself, I've had to give up corn--in any form--because it causes a nasty and painful case of eczema.
Our tradition is to hold a large Thanksgiving for family, friends and a wider circle of people... and that has meant, at times, some serious food labeling so that people know what they can or should eat.
It would be unethical to force or deceive people into eating things that cause them physical harm or distress. That's obvious when it's physical distress, but I think it's generally true as well for emotional distress as well. It's none of my business when a vegetarian decides to lapse and have a small slice of the smoked turkey--but it would be incredibly arrogant, and unethical, for me to intentionally slip them some disguised meat in a dish they thought was "safe."
But there are many more ethical issues to consider. Believing that working conditions should be safe and humane, and that workers should be paid a living wage--as I do--what does that mean when I buy food that's inexpensive? Does that mean that someone is unable to afford shelter and food for himself or herself--and for their family? Is eating that food ethical? Particularly right now, facing a serious economic crisis, we have to face both sides of that equation. Is everyone involved in growing that food, getting the food to the table, and eating it being treated ethically?
It runs both ways.
If I'm buying food that I expect to be safe and organic--or fairly traded--and those assurances are lies, there's clearly an ethical lapse.
But for a moment, assume that those involved in growing and transporting the food are getting a decent wage and working conditions. Assume the food is organic. Fairly traded. But it's shipped from around the world to get it to me, consuming a significant amount of fossil fuel and adding to the problem of climate change. Is it ethical for me to buy and eat it? Is it ethical for the grower to ship it to where it can be marketed to me?
My own sense is that it's going to be a very complex ethical calculus to decide what "ethical eating" means. The answers may not be the same for every person, and they may change as one asks the question in different places, and at different times of year.
For my family, our slowly evolving answer has been to look for and buy certain things preferentially. Some years ago, that meant we began to eat more and more organic food. We started to make a point of looking for evidence of fair trade practices. More recently, after reading Barbara Kingsolver's Animal, Vegetable, Miracle, we got serious about buying locally grown food. Each of those is an ethical choice, and each of them can easily conflict with the others... and with other concerns.
My sister and her family live in Anchorage. Buying locally grown food is very much a seasonal thing for them; winter produce comes from somewhere else, somewhere far away, for them. No matter how much they may decide that eating locally is important... it's unlikely that they'll manage to eat as locally as we might, living here in Southern California. On the other hand... it's easier for them, in some cases, to know that the food that they eat is healthy, and that those involved in getting it to the have a decent life; they live in a smaller community, and the farmers and fisherfolk aren't people far, far away from them.
I'm an omnivore. I'm not horrified by the idea that what I'm eating was a living being. Everything one might eat (other than a number of chemicals that I'd recommend against for various reasons) was a living being, to my way of thinking. The criticism that eating other animals is a result of speciesism never carried much weight for me. Essentially every life form depends on the death of other life forms. That I can empathize and, I believe, understand a dog or cow more easily than I can a tree or a carrot doesn't change the fact that each of them are living beings, and that to eat them (or turn them into animal food or paper or buildings) is still killing another living being. Asserting that it's speciesist to eat animals baffles me. Why is it not equally speciesist to eat plants? They--and we--are all part of real, living species. Each individual life form tries to survive, and each species does too.
So my point is that if any life has the right to survive by consuming any other life form, it's fundamentally ethical, because it's necessary, and as I hold life to be sacred... it has a right to continue to exist. That turns out to be more of a right as a species, since for life to continue, it has to consume other life. There is a fascinating dynamic here, where every creature naturally tries to continue to live--and must eventually die and feed other life--and yet the species are not really concerned with the survival and life of any individual. To the species, what is important is that it, collectively, does well and survives.
Arguably then, those species that we humans have entered into relationships with that are often terms "domesticated" have generally done very well. Wheat, corn, cattle, chickens, dogs and cats--among others--have done very well as species. There are, without question, many, many times more individuals of those species alive and living in more places than there would be if human beings were out of the picture.
Exterminating a species, or a distinct population, is a horror. When talking of human beings, we refer to such things as genocide, and consider it to be one of the ultimate crimes. That we are currently exterminating species of all kinds at rates that nature usually reserves for disasters like hitting the earth with a very large meteor should give us pause. If we're worried about the ethics of our relations with other species... I think we should be worrying far more about those we are driving extinct than those we arrange to be numerous and eat. For me, the extinction of the passenger pigeon and other such creatures have to understood as ethical failings vastly larger than the question of whether eating a steak is ethical.