A broader kind of problem for this semantic thesis (as well as to moral relativists more generally), raised by Coliva and Moruzzi (2012) is that it succumbs to the progress argument, an argument that famously challenges, in particular, cultural relativists (as well as indexical contextualists) about moral judgments by insisting that moral progress is both evident and not something the relativist can countenance (e.g., Rachels 2009). A third and particularly important kind of worry, addressed by Capps, Lynch and Massey (2009), involves explaining the source and nature of moral relativity, on a truth-relativist framework. Specifically, they claim that