When people are trying to determine whether an entity is capable of having certain kinds of mental states, they can think of it either from a functional standpoint or from a physical standpoint. We conducted a series of studies to determine how each of these standpoints impact people's mental state ascriptions. The results point to a striking difference between two kinds of states—those that involve phenomenal consciousness and those that do not. Specifically, it appears that ascriptions of states that involve phenomenal consciousness show a special sort of sensitivity to purely physical factors.