 Suppose, however, that evolutionary influences not only did not design our faculties to track moral truths, but did positively shape them in ways that have pervasively conditioned the content of our moral thought and feeling, through evolved emotional dispositions or “domain specific modules” that provide us with inherited moral instincts that shape our beliefs. Debunkers have claimed that this is the case and argued that it has deep metaethical implications. Though there are a variety of formulations of such arguments, with somewhat different targets (some attacking moral knowledge itself, others seeking only to undermine moral realism by showing that it would saddle us with moral skepticism), a core argument based on the work of Sharon Street may be spelled out roughly like this: