 Another a priori objection to DMR was suggested by Philippa Foot (1978a and 1978b) in a response to emotivism. Just as there are shared criteria of ‘rude’ such that not just anything could be considered rude, she argued, there are shared criteria of moral concepts such that not just anything could be a moral virtue or obligation. For example, there are substantial constraints on what could be considered courage. Hence, there are significant limits to the extent of moral disagreements.