Why is there a felt asymmetry between cases in which agents defer to testifiers for certain moral beliefs, and cases in which agents defer on many other matters? One explanation influential in the literature is that having understanding of a proposition is both in tension with acquiring belief in the proposition by deferring to another's testimony and distinctively important when it comes to moral propositions, as compared with what we might think of as many ‘garden variety’ facts. My project in (...) this paper is to offer a new and more defensible version of this explanation. This will involve re-conceiving understanding as a richer state than it is commonly thought to be, requiring affective and motivational engagement with reasons as well as cognitive facility. I also offer a new explanation of the tension between understanding and deference to testimony. (shrink)