Scott responds to three concerns about embryo selection: embryo personhood rights, loss of trait diversity, and the ethics of preventing disabilities, arguing that none of these objections are fatal to the technology.
Longer summary
Scott Alexander responds to three major concerns about embryo selection raised in response to a previous post. First, he addresses whether embryos have personhood rights, arguing that embryos lack the qualities (consciousness, intelligence, etc) that make humans morally valuable. He refutes various counterarguments about potential personhood and responds to edge cases like sleeping hermits. Second, he discusses concerns about trait diversity, arguing that the technology's limited power and slow adoption mean diversity concerns are premature. Third, he addresses the ethics of telling disabled people you'd prefer they didn't exist, comparing it to other situations where we try to prevent certain conditions without devaluing existing people.
Shorter summary