David M. Rosenthal is a philosopher at the City University of New York who has made significant contributions to the philosophy of mind, particularly in the area of consciousness. He was educated at the University of Chicago and then Princeton University. Besides philosophy of mind, Rosenthal has interests in the related field of cognitive science and also has done some work in the areas of philosophy of language, metaphysics, ancient philosophy, and 17th-Century rationalism.
Rosenthal is best known for his higher-order-thought (or “HOT”) theory of consciousness. He argues that a mental state is conscious if one is conscious of oneself as being in that state, and that one is conscious of being in such a state by having a thought that one is in it. These “higher-order thoughts” are rarely themselves conscious, and they are distinct from the states they are about.
Rosenthal has also developed a “homomorphism theory” of the mental qualities, which enables the individuation of mental qualities even when they occur without being conscious, as in subliminal perceiving and in blindsight. Mental qualities on that theory are individuated by their positions in a quality space that pertains to a particular sensory modality. More specifically, each quality occupies a position in its quality space homomorphic to the position in a corresponding quality space of the physical perceptible property to which that mental quality enables perceptual access.
Because the quality spaces of perceptible properties are each determined by an individual’s ability to identify sample qualities as distinct or identical, independently of whether the relevant qualitative states are conscious, mental qualities can occur without being conscious. They occur consciously when one is conscious of oneself as being in the relevant qualitative state, and hence when one has a HOT that one is in that state.
Rosenthal’s HOT theory of consciousness resembles in some ways the traditional inner-sense theory, on which we are aware of conscious states by perceiving them. This theory has also come to be known as higher-order perception. Rosenthal’s theory also resembles somewhat the theory of Franz Brentano, on which our awareness of our own mental states is internal to those mental states.
But the HOT theory avoids various difficulties that face the inner-sense theory, e.g., the difficulty about what sensory modality the inner sense could have (2004). And because the HOTs Rosenthal posits, unlike Brentano’s internal awareness, are external to the mental states they make one conscious of, the theory avoids difficulties Brentano’s theory encounters about the individuation of mental states (2004; 2005, ch. 2).
Rosenthal’s HOT theory also deals effectively with the difference between conscious states and mental states that are not conscious, which both Brentano’s theory and Fred Dretske’s first-order theory of consciousness arguably have difficulty with.
Rosenthal is currently working on function of mental states’ being conscious, which he argues is minimal, and on explaining why mental states do ever occur consciously if little utility results from their being conscious. He argues that we must explain that conscious occurrence of purely intentional states, such as thoughts, by appeal to different considerations from those that allow us to explain the conscious occurrence of states with qualitative character.
Rosenthal has also written extensively about the connection between consciousness, thought, and speech, and has edited several anthologies.
* Consciousness and Mind (2005)
* Materialism and the Mind-Body Problem – editor (1971); second edition (2000)
* The Nature of Mind – editor (1991)
* Applied Ethics And Ethical Theory – editor (1988)