Researchers have started seriously considering the epistemic issue of whether and when we can claim an artificial intelli- gence (AI) has developed machine consciousness. Most cog- nitive theories of consciousness employ a functional character- ization of the property of consciousness. That is, they are com- mitted to an account of consciousness as a rule-governed pro- cess over mental states. Some cognitive scientists concerned with AI advocate an epistemically behaviorist approach to ma- chine consciousness; however, such approaches taken ontolog- ically, systematically fail to satisfy reasonable intuitions about in what consciousness ought to consist, and taken epistemi- cally, fail to provide sufficient evidence to individuate any in- ternal property, including consciousness, in non-human sub- jects. Therefore, in order to assess consciousness in ways that adequately account for reasonable intuitions as to its proper definition, such that we can reasonably assert the presence of machine consciousness in some AI, it is necessary to propose, test, and revise, functional theories of consciousness.