It is often claimed in the literature in philosophy that qualitative mental properties are intrinsically conscious, and cannot occur without being conscious.  Rosenthal rejects that claim, and has developed a positive account of qualitative consciousness that is thoroughly realist about conscious mental qualities, but explains what mental qualities are independently of consciousness.  That fits well with HOT theory, on which a state's being conscious is never an intrinsic property of that state.  But Rosenthal argues for his account of mental qualities independently of HOT theory (Rosenthal, 2005. chs. 5–7; 2015).
