Higher-Order Thoughts and The Consciousness Paradox

Higher-Order (HO) theories of consciousness have in common the idea that what makes a mental state conscious is that it is the object of some kind of higher-order representation. In this exclusive interview, Rocco Gennaro discusses Higher Order Theories and the Consciousness Paradox, which asks the question – how it is possible to hold a number of seemingly inconsistent views, including higher-order thought (HOT) theory, conceptualism, infant and animal consciousness, concept acquisition, and what he calls the HOT-brain thesis?

Richard Bright: Can we begin by you saying something about your background?

Rocco Gennaro: Sure, I grew up in New York City and went to Hunter College (CUNY) as an undergraduate.  I then went to Syracuse University and earned my Ph.D. in 1991.  I had then been at Indiana State University in Terre Haute for fourteen years before moving to the University of Southern Indiana (in Evansville IN) in 2009 where I am now Philosophy Department Chairperson and Professor of Philosophy.

My primary research and teaching interests are in Philosophy of Mind/Cognitive Science, Consciousness, Metaphysics, Early Modern History of Philosophy, and Applied Ethics.  (I also have both personal and academic interest in music, sports, aesthetics, and Eastern Philosophy.)  I have published eight books (as either sole author or editor) and over forty articles and book chapters in these areas.  Most recently, I have published a book entitled The Consciousness Paradox: Consciousness, Concepts, and Higher-Order Thoughts (The MIT Press, 2012) and edited Disturbed Consciousness: New Essays on Psychopathologies and Theories of Consciousness (The MIT Press, 2015).  I am currently writing a book entitled Consciousness for Routledge Press (forthcoming 2016), and editing an anthology entitled The Routledge Handbook of Consciousness (forthcoming 2017).  I am also the Philosophy of Mind/Cognitive Science area editor for the Internet Encyclopedia of Philosophy

RB: Your research and writing involves discussing Higher-Order (HO) theories of consciousness, which postulate that consciousness consists in perceptions, thoughts, or beliefs about first-order mental states. What are first-order mental states and how do they relate to higher-order states?

RG: First-order mental states are world-directed states, such as a perception of an outer object or a desire for something cold to drink.   A higher-order mental state is a meta-psychological or meta-cognitive state, that is, a mental state directed at mental state.  Higher-order states are one level up, so to speak, from first-order states.

RB: What distinguishes ‘creature’ consciousness from ‘mental-state’ consciousness?

RG: State consciousness refers to when we speak of an individual mental state, such as a pain or perception, as conscious.  On the other hand, we also often talk about organisms or creatures as conscious, such as when we say that “human beings are conscious” or “cats are conscious.”  Creature consciousness is simply meant to refer to the fact that an organism is awake, as opposed to sleeping or in a coma.  Arguably, some kind of state consciousness is normally implied by creature consciousness, that is, if a creature is conscious, then it must have at least some conscious mental states.  However, there may for example be instances of state consciousness without creature consciousness (such as in vivid dreaming).  Most contemporary theories of consciousness tend to focus on state consciousness.

RB: When does a mental state become conscious?

RG: As a higher-order thought (HOT) theorist, it is natural to start with the highly intuitive claim that has come to be known as the Transitivity Principle (TP). One motivation for HOT theory is the desire to use this principle to explain what differentiates conscious and unconscious mental states:

(TP) A conscious state is a state whose subject is, in some way, aware of being in it.

Thus, when one has a conscious state, one is aware of being in that state.  For example, if I am having a conscious desire or pain, I am aware of having that desire or pain.  HOT theory says that the HOT is of the form “I am in M now,” where M references a mental state.  Conversely, the idea that I could be having a conscious state while totally unaware of being in that state seems very odd (if not an outright contradiction).  A mental state of which the subject is completely unaware is clearly an unconscious state.  For example, I would not be aware of having a subliminal perception, and thus it is an unconscious perception.  So a mental state M becomes conscious when there is a HOT directed at M. For example, my desire to write a good book becomes conscious when I am (noninferentially) “aware of” the desire.  Intuitively, it seems that conscious states, as opposed to unconscious ones, are mental states that I am “aware of” in some sense.  Any theory that attempts to explain consciousness in terms of higher-order states is known as a higher-order (HO) theory of consciousness.

RB: Are there different kinds of Higher Order theories?

RG: Yes, there are many different versions of HO theory, with the most common division between higher-order thought (HOT) theories and higher-order perception (HOP) theories. HOT theorists, such as David Rosenthal (and myself), think it is better to understand the higher-order state as a thought of some kind.  HOTs are treated as cognitive states involving conceptual components.  HOP theorists urge that the higher-order state is instead a perceptual state that does not require the kind of conceptual content invoked by HOT theorists (such as in David Armstrong and William Lycan, though Lycan has recently changed his mind).  There are other “higher-order theories” such as Peter Carruthers’ Dispositional HOT theory (or “dual-content” theory).  Robert Van Gulick has also explored an alternative that he calls “higher-order global states” (HOGS) whereby a lower-order unconscious state is “recruited” into a larger state, which becomes conscious partly due to the implicit self- awareness that one is in the lower-order state.  Although not really a “higher-order theory,” another importantly related theory is the so-called “self-representational theory of consciousness,” championed by Uriah Kriegel, which holds that a conscious state is directed both at the world and back at itself.  I critically discuss all of these other views in The Consciousness Paradox (especially in chapters three and five). 

RB: If we grant that non-human creatures are conscious, how does Higher Order theories relate to non-human creatures?

RG: Actually, one of the more common objections to HOT theory is that it rules out at least most animal consciousness because animals cannot have what seem to be fairly sophisticated HOTs or “I-thoughts” of the form “I am in mental state M now.”  The allegation is that HOT theory rules out animal consciousness because animals (or at least most animals) do not possess such sophisticated I-concepts (= self-concepts) and mental concepts.  Indeed, even one HOT theorist accepts this rather radical conclusion (Carruthers).  However, I have argued that (for example) experimental evidence on animal memory and metacognition strongly suggests that many animals have the self-concepts and mental-state concepts necessary to form I-thoughts.  I also reply to the claim that having I-thoughts requires having thoughts (and thus concepts) directed at others’ mental states.  One example of memory and self-concepts can be found in scrub jays.  They are food-caching birds, and when they have food they cannot eat, they hide it and recover it later. Because some of the food is preferred but perishable (such as crickets), it must be eaten within a few days, while other food (such as nuts) is less preferred but does not perish as quickly. In cleverly designed experiments using these facts (by Clayton, Emery, and Dickinson), scrub jays are shown, even days after caching, to know not only what kind of food was where but also when they had cached it. I present much more evidence of this kind in chapter eight of The Consciousness Paradox. Some of these same issues arise with respect to infant consciousness, which I discuss in chapter seven.

RB: What is the difference between a conscious state and an unconscious state?

RG: As was mentioned above, an unconscious mental state is a mental state of which one is unaware (and so lacks a HOT directed at it) whereas one is aware of one’s conscious states.  Perhaps the most fundamental and commonly used notion of “conscious” in the literature is captured by Thomas Nagel’s famous “what it is like” sense.  When I am in a conscious mental state, there is “something it is like” for me to be in that state from the subjective or first-person point of view.  When I smell a rose or have a conscious visual experience, there is something it “seems” or “feels like” from my perspective. An organism such as a bat is conscious if it is able to experience the world through its echolocation senses.  There is also something it is like to be a conscious creature, whereas there is nothing it is like to be a table or tree.  There is also nothing it is like to be in an unconscious mental state. Again, a HOT theorist believes that the best way to explain the difference between conscious and unconscious states is the presence or absence of a HOT.

RB: Following on from the last question, in order to understand the nature of the conscious/unconscious distinction, there is a very common situation in which you’re awake but your behaviour is habitual. Your behaviour might be responding to stimuli in the environment, but you’re not actually able to report on them because it’s just habitual behaviour. The classic example of this is when you are driving.  How does HO theories account for this?

RG: I think the best reply here is that even though you are still having some first-order conscious perceptions of the road and outer environment, there is significantly less attention being paid to the environment in those kinds of cases precisely because the behaviour has become habitual.  Our minds wander and we may even periodically introspect (focus on our own mental states) for a while during a long familiar drive.  So there’s both creature and state consciousness of the road etc. but one’s attention is only peripherally focused there (after all, it’s not as if those parts of our visual field become dark or entirely blind – wouldn’t we crash otherwise?). The habitual nature of the behaviour may also explain why we often do not afterwards remember much of the drive.

RB: What is the paradox of consciousness?

RG: In addition to further defending my own version of HOT theory in The Consciousness Paradox, I am interested in solving what I take to be a larger underlying paradox, which is basically how it is possible to hold the following set of apparently inconsistent yet independently plausible theses:

1. The HOT Thesis: A version of the HOT theory is true (and thus a version of reductive representationalism is true).

2. The Hard Thesis: The hard problem of consciousness, that is, the problem of explaining exactly how or why subjective experiences are produced from brain activity (or from any combination of unconscious mental activity), can be solved.

3. The Conceptualism Thesis: Conceptualism is true, that is, all conscious experience is structured by concepts possessed by the subject.

4. The Acquisition Thesis: The vast majority of concepts are acquired, though there is a core group of innate concepts.

5. The Infants Thesis: Infants have conscious mental states.

6. The Animals Thesis: Most animals have conscious mental states.

7. The HOT-Brain Thesis: There is a plausible account of how HOT theory might be realized in the brain and can lead to an informative neurophysiological research agenda.  Alternatively: HOT theory is interestingly related to and consistent with a number of leading empirical theories of consciousness.

RB: Can there be an overall theory of consciousness?

RG: Yes, I think there can be an overall theory of consciousness and HOT theory takes an important step in that direction. However, we also ideally need an account of how HOT theory is realized in the brain.  I offer some neurophysiological evidence toward that end in The Consciousness Paradox (especially in chapters four and nine) in terms of key brain structures and the interaction between them, but it would be premature to claim that we have all the answers there.  One issue is whether or not the prefrontal cortex (PFC) must be active in order to have HOTs. Unlike many others, I do not think that all HOTs (and thus conscious states) require activity in the PFC. Still, there are of course many philosophers and scholars who think that there cannot be a successful reductive explanation of consciousness.  I disagree with them.



MIT Press Book Links:

The Consciousness Paradox: Consciousness, Concepts, and Higher-Order Thoughts (2012)


Disturbed Consciousness: New Essays on Psychopathology and Theories of Consciousness (2015)


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