  Our moral judgments (about particular cases as well as about general principles) seem to float disconcertingly free from our normal sources of evidence concerning the nature of the world. We cannot see, touch, taste, or smell value or rightness or virtue, even as we can see, touch, taste, or smell some of the things that have value or that are right or that manifest virtue. So how do we learn about value and rightness and virtue themselves?  What grounds do we have for thinking our various moral judgments link up appropriately with what they are judgments of?