Commentary on ``The cognitive functions of language'' by Peter Carruthers
Abstract: 49 words
Main Text: 969 words
References: 25 words
Total Text: 1043 words
Carruthers draws heavily on Mithen (1996) for his argument that the thoughts of pre-humans were sealed in separate compartments such as social understanding (for dealing with the conspecifics in ones group), technical understanding (for dealing with tools), and understanding of the natural world (for foraging and hunting). Mithen's thought-provoking account is largely arrived at by speculation from the archaeological record, rather than by experimentation on non-humans. Not much about detailed brain organization can be gleaned from remains of bones, tools and campsites. We are skeptical about this proposed modularity, on the grounds that it is unparsimonious and raises more problems than it solves.
What C calls conceptual modules (which include geometry, colour and theory of mind) are claimed to produce non-conscious representations, like THE TOY IS IN THE CORNER WITH A LONG WALL ON THE LEFT AND A SHORT WALL ON THE RIGHT. This is, according to C, what animals and pre-linguistic children have in their minds. This kind of recursive and syntactically complex form of mentalese is, according to C, module-specific. All these complex forms of representation are sitting there, waiting for the evolution of the language faculty to connect them: "we are supposing that this interface became modified during the evolution of language so that thoughts deriving from distinct conceptual modules could be combined into a single natural language sentence."
The assumption of the existence of k different and yet compatible mentaleses is non-parsimonious. If all these representational modules evolved independently, we need to explain how they arrived at forms compatible enough to be simply connected by the evolution of one further domain-general module. Similar mechanisms would need to be found for all (k-1) other modules (colour, movement, audition, kinaesthesia, theory of mind, etc.). C needs k parallel stories, with no guarantee that they will converge on compatible forms. Thanks to some further miracle, these mentaleses would be compatible enough to be easily combined in linguistic sentences.
For instance, if predicate-argument structure is common to all specific modules, then to the extent that these modules are truly independent, separate explanations would have to be given for the emergence of this common structure. But if similar conditions in each domain give rise to predicate-argument structure (for instance, the existence of middle-sized salient objects, to which attention can be drawn, as suggested by Hurford (2002)), then the domains are not completely distinct. It is surely implausible that there is no overlap between mechanisms for thinking about social life and hunting or foraging. Chimpanzees, for example, hunt in social groups for colobus monkeys. One chimpanzee will block the prey's exit in one direction, while another approaches from the other direction. This involves integration of social cooperation with hunting behaviour. At another level, the mechanisms involved in seeking and grasping nits during social grooming are likely to be similar to those involved in seeking and grasping insects for food, from the ground; grooming seems to be a case of hunting inside social interaction. Can we suppose that a chimpanzee's thoughtful strategies for catching nits during grooming are isolated from its strategies for catching insects from the forest floor?
Another separate difficulty with C's proposals involves his view that language can be a necessary condition for certain kinds of thought, yet not constitutively implicated in those forms of thought. C explains this initially perplexing view with a diachronic/ontogenetic proposal. The picture is that, during childhood, a person hears a full-fledged utterance with some domain-general content, interprets this by accessing its LF, and thereby gains access to a kind of thought previously inaccessible to him/her. The child's first access to such a thought must be through (fully fledged) language, but in later life, the person can access this thought directly via its LF, and the phonological trappings do not necessarily come to mind. This is C's position.
The interpretation of any utterance is seldom, if ever, accomplished in purely bottom-up fashion. That is, some contextual clues as to the general kind of meaning intended by the speaker are always deployed by the hearer in accessing the meaning of an utterance. C's account implies that children interpret utterances with domain-general content, which open up certain classes of thought to them, in purely bottom-up fashion, with no prior inkling of the LF treasure they are going to find at the end of the interpretation process. But this seems most implausible. Children, in particular, who know less of their language than adults, must rely more on top-down clues to meaning than do adults.
We need to ask how a child first learns the meaning of a particular domain-general natural language predicate word, such as English same or individual or three. According to C, the child must hear an utterance using the word, for example `This nut is the same colour as my skin', and without having prior access to the concept SAME, interpret the utterance correctly, and thereby gain access to the concept SAME. We are in a Fodorian paradox here, and C. doesn't show us how to get out of it. If "non-domain-specific, cross-modular, propositional thought depends upon natural language", there is an ontogenetic bootstrapping problem. Non-specific thoughts must rely on domain-general concepts like SAME, INDIVIDUAL or THREE. No account is given of how such concepts are acquired. Furthermore, C does not tell us where such concepts are supposed to reside since they do not belong to any specific module. If they are ascribed to a "central" system, then a (k+1)th mentalese has to be postulated. Such a central system could, both ontogenetically and phylogenetically, play the role of integrator. If so, there is no need to grant this role to syntax and phonology. If there is no such central conceptual system, then the existence of any domain-general concept is problematic. Words alone, and their juxtaposition through syntax, can't bring them to existence in the mind.