Moral Understanding and Cooperative Testimony

It is has been argued that there is a problem with moral testimony: testimony is deferential, and basing judgments and actions on deferentially acquired knowledge prevents them from having moral worth. What morality perhaps requires of us, then, is that we understand why a proposition is true, but this is something that cannot be acquired through testimony. I argue here that testimony can be both deferential as well as cooperative, and that one can acquire moral understanding through cooperative testimony. The problem of moral testimony is thus not a problem with testimony generally, but a problem of deferential testimony specifically.