 As a side note, there has been a debate, ongoing since the early 1990s (Cavalieri and Singer 1994) about whether great apes deserve special legal protection amounting to ‘human rights’. The crux of the debate is not whether the great apes have consciousness per se (this seems to be assumed by most participants of the debate, on both sides), but whether they have personhood. Personhood is a vexed notion, but is generally thought to be related to certain forms of agency and self awareness, and is often thought to be tightly coupled to moral status, as reflected in this debate (DeGrazia 1997; SEP article on Moral Status of Animals; Varner 2012). Though not essential to phenomenal consciousness, personhood is often thought to presuppose consciousness, and so perhaps is best thought of as a level of elaboration or complexity of consciousness.