Block argues for a distinction between phenomenal consciousness [PC] and access consciousness [AC] on the basis of his ‘overflow’ argument. Some have thought that this distinction might limit the possibilities of studying consciousness, as it suggests the existence of conscious mental states whose contents can’t be reported. After distinguishing theoretically between PC and AC, I will summarise Block’s overflow argument for their factual distinction. Highlighting that Block makes two related but separate modal claims about the PC/AC distinction, I will show that the arguments he offers at most support the weak claim that a subject S can have a mental state which is P-conscious but which isn’t A-conscious. But the assumptions on which his argument for the weak claim rest prevent any supporters of his argument from making the strong claim that an individual can have a mental state which is P-conscious but which can’t be A-conscious. And if the overflow argument can’t motivate this stronger claim then there’s no reason to think that any mental state which is P-conscious can’t be made A-conscious given the right circumstances. In which case, even if Block’s argument succeeds, there’s no reason to think that there are inherently inaccessible and thus unreportable conscious mental states. So fears about the limitations of the possibility of the study of consciousness due to the existence of such mental states on the basis of the overflow argument can be allayed
