"But You Eat Plants!"

So, I mentioned in my post about the Can God Exist? event that Ken Miller, in response to a cry of support for vegetarianism, responded that, after all, vegetarians eat plants, so every time we eat we are killing hundreds of thousands of beautiful little plant cells, which are after all the subject of his life's work. In that post I dismissed his argument fairly off-handedly, but subsequent experience leads me to think it needs a more thorough debunking. Here goes, below the fold.
Fundamentally, his argument is just aimed at a very narrow constituency of vegetarians. Specifically, the concern he raises is only valid if one's reason for being a vegetarian is because you oppose the killing of any living being. I think some Buddhists are vegetarians for this reason, and I think some of them are devoted and radical enough to try not to eat anything that involved killing plants, either. For any vegetarians out there who have this motive but do eat plant-killing foods, well, yeah, you're not fully living up to your principles.

The objection Dr. Miller raises, however, is irrelevant for my kind of vegetarianism. My vegetarianism is based in the principle of kindness, specifically the part about not causing harm or suffering. I believe that most animals are and almost all animals might very well be sentient; therefore, I don't kill them; therefore, I don't consume products that involve killing them, for eating or any other use. Plants, on the other hand, give us no reason to think they either are or might be sentient: they lack any sort of nervous system, let alone a central one. So killing and eating a plant causes no suffering, no harm, and is therefore perfectly fine under this system. To paraphrase the great Jeremy Bentham, the question is not can they talk? nor can they reason? nor even do they have wondrous cell structures?, but can they suffer?

There are several other kinds of vegetarianism, but I don't think Miller's argument applies to any of them, either. Some people are vegetarians for health reasons; obviously, they're not behaving out of any moral concern at all (e.g. Hitler, who was a vegetarian because he thought animals were too impure to be worthy of feeding him). Some people are vegetarians for environmental reasons. Care to explain why an environmental vegetarian would give a damn about Miller's argument? Likewise, some are vegetarians because meat-eating is absurdly wasteful of food, and ending meat-eating would make ending world hunger really, really easy. Hard to see how the fact that they're killing plants matters to them, isn't it?

There's a further sense in which Miller's objection gets its logic wrong, though. Stipulate that killing and eating plants is bad. Unless we think that it is at least as bad as killing and eating animals, it is still better to eat a plant than an animal. Vegetarianism could even theoretically still come out ahead if killing plants can be as bad or worse than killing animals, because it takes, for instance, 16 pounds of grain to produce 1 pound of beef. So the amount of killing involved in creating X units of grain would have to be 16 times worse than the amount of killing involved in creating X units of beef in order for meat-eating and vegetarianism to come out equivalent. Maybe vegetarianism isn't perfect, but Miller is trying to make the perfect the enemy of the good in order to argue for the bad.

And moreover, Miller isn't just wrong. He displays a fundamental misunderstanding of what vegetarians are all about. He gave this answer in response to a comment that God could've made the world a less cruel place by making us all vegetarians (never mind that, under Miller's "best-of-all-possible-worlds" argument, this is probably practically impossible, even for god!). That commenter obviously was making a sentience-based argument, and Miller just didn't get that. Yes, if we take sentience out of the equation the argument for vegetarianism becomes a lot weaker. But sentience is the central point: if a being is sentient, then in harming it you cause suffering, and are committing a morally wrong act, while if it is not, you cause no suffering in harming it, and are on morally neutral ground. That is the fundamental moral argument for vegetarianism, at least an animal-rights vegetarianism. If you don't get that, then you don't get what we vegetarians are talking about.