The Higher-Order Approach to Consciousness:
The Hot Ticket or In Hot Water?
In a recent paper Ned Block (Block manuscript) has renewed his attack on
the higher-order thought (HOT) theory of consciousness.1 The objection that he is
articulating is distinct from any of his previous objections (Block 2009; 2007) and is
a reaction to David Rosenthal’s response to the empty higher-order thought
problem (Rosenthal 2005; all quotes from David Rosenthal will be from this book
unless otherwise noted). In this paper I will briefly rehearse Rosenthal’s strategy to
avoid the empty HOT problem after which I will lay out Block’s new objection and
Rosenthal’s response before I suggest what I consider to be a better solution to the
problem.
The key step in the higher-order strategy for demystifying phenomenal
consciousness is the separation of consciousness from the qualitative and
intentional properties of our mental states that it gives us access to. According to the
higher-order thought theory a conscious mental state is one that I am conscious of
myself as being in, in some suitable way of being conscious of myself. So, in a typical
case of consciously seeing blue, for instance, we will have a mental state that has
qualitative character, we’ll call it blue* following Rosenthal (page 204), and also a
higher-order thought to the effect that one is in a blue* state. Given this one might
wonder what we are to say in cases where the first-order and higher-order content
doesn’t match.2 So if one is in a blue* state but one has a higher-order thought to the
1
The paper is not yet available. I was lucky enough to see a draft and to hear the objection live at the
NYU Mind and Language Seminar March 9th 2010.
2 In fact many people have wondered; see Weisberg 2010 for a nice discussion.
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effect that one is in a red* state, what is it like for one? Is it like seeing blue for one
or is it like seeing red for one?
In response to this question Rosenthal has argued that the phenomenology
goes with the HOT. As Rosenthal says, “there is something that it is like for one to be
in a qualitative state when one is conscious of oneself as being in that state,” (p. 203)
and “nothing that it’s like for one to be in a qualitative state that isn’t conscious,” (p.
10). The sensory qualities of the first-order states (that is to say, the starred
properties) play no role in determining the phenomenal character of a conscious
experience other than that of concept acquisition in the first place. In fact even if
there is no first-order state at all the phenomenology goes with the HOT. Rosenthal
is very clear about this saying,
Since there can be something that it’s like for one to be in a state with
particular mental qualities even if no such state occurs, a mental state’s being
conscious is not strictly speaking a relational property...A state’s being
conscious consists in its being a state one is conscious of oneself as being in
(p. 211)
The mental state that is conscious is just the one that the HOT represents oneself as
being in and so in this case the conscious mental state is a notional state. It suffers
from intentional inexistence. It follows from this that there are conscious mental
states that have no neural correlates. We thus end up with a dualism about
consciousness of a new variety. There are some conscious mental states that exist
physically in the brain and there are other conscious mental states that exist only
notionally as the content of a HOT.3
3
From personal communication I gather this to be Rosenthal’s own view. Weisberg seems to have
the slightly different view that the objects are the same in both cases and so avoids a dualism. At least
this seems suggested by the way that Block reads Weisberg
2
What are we to say about this? Before answering that question it is important
to stop and discuss an important preliminary point. Block distinguishes between
what he calls the modest and ambitious versions of the HOT theory. The modest
version of the theory makes only a claim about the way we use the word
‘consciousness’. In the modest version the theory states only that a conscious mental
state is one that I am in some sense aware, or conscious, of. It makes no claims about
phenomenal consciousness. The ambitious version of the theory goes beyond this
and claims to explain phenomenal consciousness as well. In this sense Rosenthal’s
HOT theory is ambitious. It is because of the ambitiousness of the theory that Block
sees a problem. The transitivity principle says that a conscious mental state is one
which I am conscious of myself as being in, and this is supposed to account for
phenomenal consciousness, but when one has an empty HOT one has a
phenomenally conscious mental state (we must since Rosenthal is an ambitious
theorist) and we are not aware of ourselves as being in it (there is not third-order
HOT); thus adopting this view –that the HOT can misrepresent their targets—
falsifies the transitivity principle.
Just to repeat; it is here that the distinction between ambitious and modest
views becomes important. If the HOT theory is merely a modest theory then we
have no problem since there would not then be, eo ipso, an episode of phenomenal
consciousness. Here is the way that Josh Weisberg (Weisberg 2010) formulates the
argument (keeping in mind that premise 1 will pose a problem only if we interpret it
as an ambitious claim because then it entails that there is an episode of phenomenal
consciousness),
3
1. If there’s something it’s like for the subject, the subject is in a conscious
state.
2. In radical misrepresentation [i.e. when empty HOTs occur], there is
something it’s like for the subject.
3. So, in radical misrepresentation the subject is in a conscious state.
4. The conscious state is either the first-order state or the higher-order state.
5. The first-order state does not exist in radical misrepresentation.
6. The subject is not aware of the higher-order state in radical
misrepresentation.
7. So, either the subject is in a conscious state that does not exist, or the subject
is in a conscious state that she is not aware of being in.
8. A subject can’t be in a conscious state that does not exist.
9. So, the subject is in a conscious state that she is not aware of being in.
But the conclusion, 9, looks like the denial of the higher-order theory’s defining
tenant. The transitivity principle requires that every conscious mental state be one
of which I am conscious of myself as being in and this looks violated here.
Both Rosenthal and Weisberg respond to Block’s new objection by
challenging the use of the phrase ‘something that it is like for one’. Rosenthal has
argued that phenomenal consciousness is not a kind of consciousness distinct from
others but is better thought of as just the result of our being conscious of our
qualitative states (Rosenthal 2002). In the sense of that phrase that matters what it
is like for one is captured by how one’s metal life appears to one and for Rosenthal
that is a matter of how one’s HOTs represent those states. Thus there is no counterexample to the transitivity principle in the offing. There is a mental state that is
conscious: The notional one. Weisberg continues this line of defense arguing that it
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is only when one assumes that consciousness is intrinsic to the state that has it that
this seems implausible. He says, for instance,
But at this point the HO theorist can hold the line and ask what underwrites
this belief? What is it that makes us so sure that conscious states aren’t just
states we represent ourselves as being in? All that’s left to support this belief,
I contend, is a (perhaps implicit) commitment to an intrinsic conception of
consciousness. (p. xxx)
It is only when we assume that consciousness is intrinsic to the state that has it that
we feel compelled to deny that it could be fully explained by a relational account but
since that is what is under dispute it is question beginning to assume it. So
Weisberg, and Rosenthal with him, concludes that it is only a tendentious
assumption that stops one from rejecting premise 8 in the above argument. If one
instead adopts a different set of platitudes as the way of identifying the data one
ends up with the view that notional states can be conscious.
Suppose that we accepted the Weisberg-Rosenthal move and we take the
transitivity principle to be only a claim about what makes a mental state a conscious
mental state. It seems hard to deny this modest claim and, as Weisberg himself
notes, it is a second further step to claim that the transitivity principle explains what
it is like for one to have a conscious mental state. Doing so is to move from the
modest version of the theory to the ambitious version of the theory. But, again, as
Weisberg himself notes, the transitivity principle –all by itself— doesn’t explain
phenomenal consciousness simply because it was not meant to explain that. It was
meant to explain what a conscious mental state consists in and it tells us that all
conscious mental states are the targets of HOTs. Given this it would be a mistake to
automatically assume that an explanation of phenomenal consciousness would look
5
exactly like our explanation of state consciousness. Does this mean that we must
give up on the ambitious HOT theory?
I do not think so. The natural thing to do at this point is to identify the
episode of phenomenal conscious with the HOT itself while still identifying the
conscious mental state as the target of the HOT. The HOT is the state in virtue of
which there is something that it is like for one to have the conscious mental state.
What reason do we have to deny that it is phenomenally conscious? There is no
issue here as long we keep all of the various kinds of consciousness straight. Let us
briefly remind ourselves of the standard taxonomy. Creature consciousness consists
in a creature being awake and responding to stimuli and so is basically a behavioral
notion. Transitive consciousness consists in our being conscious of things and so
consists in sensing and thinking; it is from here that the transitivity principle derives
its name. We also have state consciousness, which is a property of mental states.
Unconscious mental states lack this property and conscious mental states have it.
According to the transitivity principle sate consciousness consists in one’s being
suitably aware of oneself as being in some mental state. Accepting this much is
accepting the modest version of the higher-order approach. We also have
introspectively conscious states. A mental state is introspectively conscious when
one has a third-order thought to the effect that one is in a second-order state.
Introspection is the special case when our HOTs themselves become conscious. Thus
state consciousness and introspective consciousness are both explained by a specific
kind of transitive consciousness.
6
Phenomenal consciousness is the property of there being something that it is
like for one to have a conscious mental state. We identify this property as the one
that zombies would intuitively lack, the one that Mary would intuitively fail to know,
etc.4 So in the empty HOT case we can say that the notional state is state
consciousness and the HOT is phenomenally consciousness.5 Phenomenal
consciousness, on this account, does not consist in being the target of a HOT –that is
what state consciousness consists in— rather phenomenal consciousness is
identified with the act of having the higher-order thought. We can see this as taking
the modest/ambitious distinction seriously and explaining each via a separate
aspect of the higher-order theory. State consciousness is identified with being
targeted by the Hot and so with the content of the HOT phenomenal consciousness
is identified with having the HOT itself not with the content of the thought.
The HOT is not introspectively conscious –for that it would need to have a
third order state targeting it– but it is phenomenally conscious. It is the state in
virtue of which there is something that it is like for the subject and so it seems
natural to identify the property of phenomenal consciousness with having the HOT.
This is not an objection to the transitivity principle since there is no mental state
that has the property of state consciousness without being the target of a suitable
higher-order thought. There is an episode of phenomenal consciousness without it
being the target of a higher-order thought but that is no problem since phenomenal
Even if it turns out that zombies are not ideally conceivable they are plainly prima facie conceivable
and that is all that is needed to ground the intuitive notion of phenomenal consciousness.
5 I am allowing this just for the sake of argument. My own view is that the content of the HOT is akin
to a complex demonstrative of the form “I am in Dthat blue* state”. I use ‘Dthat’ loosely and only to
capture the idea that the referent of the state is picked out by the causal relation. But this is an
entirely separate issue.
4
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consciousness does not consist in being the target of a higher-order thought but
rather just is the having of the higher-order thought. Having conscious mental states
results in phenomenology because phenomenology consists in one having a higherorder thought, which is how one also has conscious mental states so it is natural that
the two should go together yet they are distinct properties.
We can then give an argument that is supposed to show that phenomenal
consciousness just is having the appropriate higher-order thought. This turns out to
be, on the present account, a surprising empirical discovery. Here is how the
argument goes. It is, roughly, the argument that Rosenthal himself gives in many
places. Take the case of listening to an orchestra. If one has no concept of what a
bass clarinet is one will not consciously experience the sound of the bass clarinet as
such, though one’s experience of it may be conscious in some other respect (that is
to say one will have the relevant first-order states with their qualitative characters
and perhaps even higher-order thoughts about them but not as having bassclarinet* qualities). Once one acquires the concept ‘bass clarinet’ one’s experience is
different in a phenomenological way. What it is like for one to hear the orchestra
will differ in precisely the sense that it will now sound like there is a bass clarinet in
the orchestra to one. The same case can be made for wine tasting.6 What cases like
this give us is data that learning a new results in new conscious phenomenology.
Extrapolating from this Rosenthal goes on to say,
My HOT determines whether what it’s like for me is, say, having a conscious
experience of magenta or a conscious experience of some nondescript red.
And, since the HOT one has can make that difference, whether or not one has
any relevant HOT at all can make the difference between there being
6
Rosenthal often does make the case in terms of wine tasting, see for instance p. 1887-188
8
something it’s like for one to be in a particular state and there being nothing
whatever that it’s like for one (p. 193)
The precise content of the HOT determines what it is like for one and this very fact
is what is supposed to aid in our explanation of phenomenal consciousness. At the
very least these kinds of data open up the space of possibilities and suggest that it
could be the case that having a HOT accounts for phenomenal consciousness.
Now, suppose that one granted that applying concepts results in a change in
one’s phenomenology but denied that HOTs can explain the existence of
phenomenology in the first place.7 Rosenthal has a response to this as well. He says,
Suppose I am in pain and that pain is conscious, but I am not aware of
whether the pain is throbbing or dull or sharp. Because the pain is conscious
there is something that it is like to be in it...suppose, now, there is some
physiological reason to think that the pain is throbbing, as opposed to dull or
sharp. So what it is like to be in this pain leaves out one of its qualitative
properties: that of being a throbbing pain and if qualitative states can occur
without one’s being conscious of all their mental qualities, what reason can
we give to deny that such states can occur without our being aware of any of
those qualities? (p. 155)
When one subtracts out the content ‘throbbing’ from the HOT one’s conscious
phenomenology lacks this aspect. If we were to add it back in one’s conscious
phenomenology would again include it. This is because “what it’s like for us to be in
a specific qualitative state is determined by the way consciousness represents that
state...by the content of the HOT,” (p.173). If we imagine again abstracting away the
content of the HOT so that one was conscious of the pain just as some sensation or
other the experience would be correspondingly more generic for the creature that
7
One could do this, for instance, by claiming that applying the concepts has a causal effect on the first
order experiences while denying that phenomenology is constituted by conceptual application.
9
had it.8 Notice that this subtraction argument is not supposed to show that applying
concepts constitutes phenomenology but rather only to show that this is a plausible
way to interpret the data of wine tasting and like phenomena. There may be other
theoretical accounts but the ambitious higher-order view remains a live option.
Of course the view that we end up with is still the higher-order thought
theory as Rosenthal defends it. All we have done is to take phenomenal
consciousness seriously. Instead of trying to deny the obvious data we can reconcile
the two. It is too often the case that the debate is framed in the way that Weisberg
puts it in his paper. You either think of conscious as something awesome and
mysterious or you think of it as something impoverished and ordinary. It seems to
me that phenomenal conscious is awesome and mysterious and still nonetheless
ultimately ordinary. But this is something that we have to discover and in so
discovering it we should not deny that consciousness is seemingly very mysterious.
One nice result of this account is that it lets us reconcile to the two sets of platitudes
about consciousness. Phenomenal consciousness is intrinsic to the state that has it,
since being a HOT is intrinsic to HOTs, and state consciousness is extrinsic and
relational.9
8
Rosenthal makes this subtraction argument in “Explaining Consciousness” page 415, which appears
in the Chalmers anthology.
9 I would like to thank Ned Block for very helpful comments on a previous draft of this paper. An
early version of the response developed here was presented at the CUNY Cognitive Science
Symposium August 5th 2010 and I am grateful to the participants for helpful discussion, especially
David Rosenthal and Pete Mandik.
10
Work Cited:
Block, N. (manuscript) “The Higher-Order Approach to Consciousness is Defunct”
Block, N. (2009) “Comparing the Major Theories of Consciousness,” in Michael
Gazzaniga (ed.) The Cognitive Neurosciences IV. MIT Press
Block, N. (2007) ”Consciousness, Accessibility, and the Mesh between Psychology
and Neuroscience,” in Behavioral and Brain Sciences 30: 481-548
Rosenthal, D. (2005). Consciousness and Mind, Clarendon Press: Oxford.
Rosenthal, D. (2002) “How Many Kinds of Consciousness?” Consciousness and
Cognition, (11) 4: 653-665
Weisberg, J. (2010) “Misrepresenting Consciousness” Philosophical Studies
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