 Whether or not the Mohists held anything like this dual-reference account, it is clear that which criteria the Mohists found relevant depended on what they found “appropriate” in comparisons of things, and the identification of these criteria was no doubt both a central part of the Mohists’ research program and a source of ongoing controversy in debates with their opponents. But given the subtlety with which the Mohists analyzed their key terms, they seem to have been increasingly sensitive to the worry that no exhaustive list is possible.