And if that's not a compelling enough counterargument, there are two additional issues with trying to conflate plants and animals in this context. First, it takes far more plants to support an omnivorous diet than a plant-based diet. Second, many plant-based products are obtainable without having to harm the plant.

Currently that's true. But it's not an essential property of the universe. Yesterday's ludicrous may be tomorrow's normal. Thus my mention of Star Trek's replicator. Imagining those were common helps make clear the ethical tradeoffs.

If everybody were used to getting any food they wanted from a magic box, then what would we think of people who insisted on doing it the old way? A guy who spent months raising animals just to murder and consume them would certainly hear about it.

A person who had a vegetable garden might just be seen as a quirky hobbyist, or he might be seen as a person doing something weird and gross, the way many Americans feel about somebody who eats organ meat or dog. They might even be seen as heretical; many religions see life as sacred, after all. And if they did it at modern, industrial scale where they destroyed square miles of ecosystem? Perhaps it would be seen as historical reenactment, or perhaps it would be taken as a sign of severe mental health problems.

As I said, I'm an omnivore. But I try to be an honest, self-aware one. I just dismembered a turkey, ripping joints apart and rending flesh from bone. I'll enjoy the meal, but I'm aware of the horror, too. That's the deal with evolution and being part of a species that is early on in the self-uplift process.