Such a response, however, will be answerable to the charge of incoherence raised by Donald Davidson against both alethic and conceptual relativism. According to Davidson, the principle of charity—the assumption that other speakers by and large speak truly (by our lights)—is a pre-requisite of all interpretation. He takes this to imply that there could not be languages or conceptual schemes that we cannot in principle understand and interpret, in other words, if a system of signs L is not recognizable as a language by us then L is not a language. Languages are either inter-translatable and hence not radically different from ours, or incommensurable and beyond our ability to recognize them as languages (Davidson 1974). The relativist, in effect, places other speakers and their languages beyond our recognitional reach and thereby undermines the initial claim that they could be radically different or incommensurable.