Many people who care about animal rights are excited about the possibility of in-vitro meat. Growing meat in a lab, without any animal attached to suffer, should let people become vegetarian without giving up tastes they enjoy. [1] There's still some animal suffering involved in in-vitro meat, because we currently use an animal-derived growth medium and you need animal cells to start the process, but for a given amount of meat you need many many times fewer animals living and suffering.

If you care about animals, the potential of people switching to eat something that causes much less suffering should probably seem promising, and at least worth further research to see if we can get the costs and animal impact down. In-vitro meat, however, is likely never going to be able to completely eliminate its dependence on animals. So do we consider this imperfect solution, or reject it for not completely solving the problem?

"I am not interested in 'less' suffering, but in 'zero' suffering for all the non-human animals that are currently caught up in the system of agricultural slavery."

And:

"In Vitro Meat is violence. It doesn't matter if it makes people eat a trillion less animals than they already are. Worldwide Veganism will make people eat NO animals ever again, so that's the only thing that it's morally valid to promote."

(Comments from two posters in this thread.)

This kind of absolutism can be attractive for its moral clarity, but it achieves this by sweeping a lot of other human-caused animal suffering under the rug. Eating vegan is not enough to cut your dependence on animal suffering to zero: there are still field mice swept up in combines, bees forced to fly from empty flower to empty flower in saturation pollination, and all sorts of animals losing their habitat to farming. [2] How can you maintain an absolutist view of animal suffering, where it's unacceptable to cause any amount of suffering through your demand for food, and still eat anything? We can't be suffering eliminators, only suffering minimizers, and it would be a shame if a desire for complete elimination of animal suffering led us to refuse to consider paths that might get us farther in that direction than others.

[1] People also make the argument that we'll be able to make this meat cheaper than current factory-farmed meat, and then people will just switch to the cheap thing. Even if it becomes the cheapest option, however, I expect there will be taste differences, and that people will eat some of both kinds and enjoy the variety. (more)

[2] See my earlier post asking what a suffering minimizing diet would look like.