[original post here]

#1: Isn't it possible that embryos are alive, or have personhood, or are moral patients? Most IVF involves getting many embryos, then throwing out the ones that the couple doesn't need to implant. If destroying embryos were wrong, then IVF would be unethical - and embryo selection, which might encourage more people to do IVF, or to maximize the number of embryos they get from IVF, would be extra unethical.

I think a default position would be that if you believe humans are more valuable than cows, and cows more valuable than bugs - presumably because humans are more conscious/intelligent/complex/thoughtful/have more hopes and dreams/experience more emotions - then in that case embryos, which have less of a brain and nervous system even than bugs, should be less valuable still.

One reason to abandon this default position would be if you believe in souls or some other nonphysical basis for personhood. Then maybe the soul would enter the embryo at conception. I think even here, it's hard to figure out exactly what you're saying - the soul clearly isn't doing very much, in the sense of experiencing things, while it's in the embryo. But it seems like God is probably pretty attached to souls, and maybe you don't want to mess with them while He's watching. In any case, all I can say is that this isn't my metaphysics.

But most people in the comments took a different tactic, arguing that we should give embryos special status (compared to cows and bugs) because they had the potential to grow into a person.

https://www.astralcodexten.com/p/my-responses-to-three-concerns-from