Block presents his now famous “Absent Qualia Argument” against functionalism. The argument implies that there can be functionally equivalent systems which nonetheless do not have the same mentality, e.g., one system (such as a person) may be in pain, whereas an alternative hypothetical system is not, despite their functional equivalence.
Block begins by describing functionalism. He describes it as a successor to behaviorism in the sense that it also specifies mental states in terms of behavioral dispositions. The difference is that functionalism conjoins these behavioral dispositions with tendencies to experience mental states. As such, functionalism is stricter in its regime for mental state attribution: it requires the system in question to have behavioral dispositions plus certain internal states.
Block then introduces the notions of ‘liberalism’ and ‘chauvinism’: liberalism is the problem a theory of mentality faces when it attributes mentality to systems which clearly do not have it. Block thinks behaviorism is such a theory: a behavioral disposition may be necessary for the possession of a certain mental state, but it is not sufficient. Chauvinism, meanwhile, is the problem faced by a theory which withholds attributing mentality to systems which clearly seem to possess it. Block’s example of a theory which falls victim to chauvinism is what he calls ‘physicalism’: the view that mental state types are equivalent to physical state types (I don’t know why he doesn’t just say type physicalism, since this is what he is describing); the theory is chauvinist because it denies mentality to any creature which does not have the same physical structures as we do.
Then Block delimits two sorts of functionalism: Functionalism (with a capital ‘F’) and Psychofunctionalism. Block describes Functionalism as the theory that functional analysis is primarily about the meaning of mental state terms, whereas Psychofunctionalism takes each functional analysis to be an empirical hypothesis. Further, if we characterize each functional property (or state) in the Ramsey sentence of a theory T (see “What is Functionalism?” for an explication of the Ramsey method) as a ‘Ramsey functional correlate,’ then we can say that Functionalism identifies mental states with the Ramsey functional correlates of commonsense psychology whereas Psychofunctionalism identifies mental states with the Ramsey functional correlates of a scientific psychology.
Block then presents two hypothetical examples of systems which can realize the same functional organization as a person, yet which we are loth to attribute mentality to. This in turn seems to indicate that functionalism falls victim to liberalism (attributing mentality to systems which do not in fact have any). The first hypothetical is a ‘homunculi head’: a body exactly like yours on the outside, with the same set of neurons leading to the head. Yet in the head, a set of tiny men run an operation, complete with a bulletin board with lights that indicate to sub-sets of the men their job in implementing an internal machine table state (i.e., their job in pushing a button connected to an output neuron and putting a card on the wall indicating the next state, which in turn serves as a guide for other little men) such that the body realizes the same machine table state as you do. All the little men are very dumb. On functionalism, the activity of the homunculi-head indicates that it has mentality just like we do; however, we clearly do not want to attribute experiences of consciousness, pain, and all the rest to the homunculi head. The example seems to indicate that functionalism is bedeviled by the problem of liberalism.
The next hypothetical is a modification of the first: the entire state of China is set up to realize the same machine table state as you do, with each individual member of the state acting like a neuron in your brain. Each person has a radio connected to the artificial body in the previous example and to the other appropriate persons. The radio is connected to the input-output neurons of the artificial body in the appropriate way, and satellites broadcast the current system state of the body. This complex system could realize your functional organization for a brief time, and yet we certainly do not want to attribute to it any mentality.
Block then dispels some ambiguity surrounding his second hypothetical: one, the system is functionally equivalent to a person, because all it is to be functionally equivalent with another thing is to have the same set of input-output-internal state relations as it does. And a Chinese-controlled homunculi head could meet this criteria, even if just for a moment. Second, the time scale of the functional realization is irrelevant. Sure, Chinese-controlled homunculi head would be extremely inefficient, realizing functional states in a slow and haphazard fashion. But all that matters is that that realization is the same as takes place in a person. Block suggests we imagine a person whose mental processes are slowed severely. Now, the person and the homunculi head can realize functional states at the same speed, and the worry is dispelled.
The above hypotheticals were directed at machine state functionalism because they made explicit reference to machine table states of a system. But an extrapolation from the examples allows Block to apply the spirit of the hypotheticals to all versions of functionalism, and this extrapolation relates explicitly to qualitative states (rather than mental states in general). All versions of functionalism say that a qualitative state (e.g., a pain) is a functional state. Yet we can imagine beings in the functional state who aren’t in pain at all. Thus, functionalism is guilty of liberalism in its extension of the ‘is in pain’ predicate to a number of systems which don’t really feel pain.
Argument: The Absent Qualia Argument*
1. Functionalism argues that qualitative states (e.g., pain) are functional states of a system, interrelated to inputs, outputs, and other internal states.
2. If one can imagine a plausible case of a system which realizes the same set of functional states that a person does, yet where we intuitively want to avoid attributing the ability to experience qualitative states to the system, then, prima facie, functionalism is plagued by the problem of liberalism. [from 1]
3. The homunculi head, whether operated by little men or the nation of China, can plausibly be said to realize the same set of functional states as a person, yet intuitively we do not want to attribute the experience of qualitative states to it.
4. Therefore, functionalism is plagued by the problem of liberalism. [3,2]