capable of entertaining some thoughts, then they will also be capable of
entertaining structurally related thoughts? Horgan and Tienson (1996)
argue not, and develop what they callthe tracking argumentfor Mentalese.
Any organism which can gather information about, and respondXexibly
and intelligently to, a complex and constantly changing environment must
have representational states with compositional structure, they claim.
Consider early humans, for example, engaged in hunting and gathering.
They would have needed to keep track of the movements and properties of
a great many individuals – both human and non-human – updating their
representations accordingly. While on a hunt, they would have needed to
be alert for signs of prey, recalling previous sightings and patterns of
behaviour, and adjusting their search in accordance with the weather and
the season, while also keeping tabs on the movements, and special
strengths and weaknesses, of their co-hunters. Similarly while gathering,
they would have needed to recall the properties of many diVerent types of
plants, berries and tubers, searching in diVerent places according to the
season, while being alert to the possibility of predation, and tracking the
movements of the children and other gatherers around them. Moreover,
all such humans would have needed to track, and continually update, the
social and mental attributes of the others in their community. (This point
will prove important in our discussion of Dennett’s views on consciousness
in chapter 9.)
Humans (and other intelligent creatures) need to collect, retain, update,
and reason from a vast array of information, both social and non-social.
There seems no way of making sense of this capacity except by supposing
that it is subserved by a system of compositionally structured represen-
tational states. These states must, for example, be formed from distinct
elements representing individuals and their properties, so that the latter
may be varied and updated while staying predicated of one and the same
thing. But then states which are compositionally structured areipso facto
systematic (and also productive) – if the state representingaRbis com-
posed of distinct representations fora,R, andb, then of course it will be
possible for the thinker to build out of those representations a represen-
tation ofbRa. And to say that propositional-attitude states are com-
positionally structuredisjust to say that they have syntax-like properties,
and hence that there is – in the intended sense – a language of thought.
In the classical account, not only are thoughts carried by Mentalese
sentences, but the transitions amongst those sentences arecomputational,
involving rule-governed causal transitions which serve to realise the inten-
tional laws of common-sense and scientiWc psychology; and those senten-
ces, and those computational transitions amongst sentences, are somehow
realised in neural states of the brain. The picture, here, is best understood
196 Forms of representation