Veganism
Updated onI'm not entirely convinced that harvesting plants is self-evidently better than harvesting animals. We can harvest some parts of some plants and it looks something like symbiosis. When you take an apple from an apple tree, the tree seems fine. You get an apple, and it gets to grow another apple. Doesn't seem like a problem.
So in that sense, veganism holds up, but only to the extent that the plant you harvest survives the process. But plenty of plants don't, and I've never heard of a vegan making this distinction, which means that vegans must believe that while killing animals for food is self-evidently immoral, killing plants isn't. But is it? It seems intuitive, until you take the persepctive of the plant.
But to be fair, everyone believes this, and we know that because most people, vegan or otherwise, can't stomach the thought of killing a steer, but I imagine few people would have reservations digging up a potato and turning it into french fries.