Download Meditations on a Cartesian Theme: Flexibility and Language in a

Meditations on a Cartesian Theme: Modularity, Language and the Flexibility of Cognition
Over four centuries ago, Descartes posed what he saw as an insurmountable challenge for mechanistic
theories of mind: Given that mechanisms are, by their very nature, highly specialised and rather inflexible,
how can one explain the manifest flexibility of human thought in mechanistic terms? Though cognitive
scientists are not much inclined to accept the Cartesian response to this problem–that the mind is not a
mechanism of any sort— Descartes’ Challenge is still very much with us today. Indeed, explaining
cognitive flexibility is among the most pressing, general problems confronting cognitive science.
One response to Descartes’ Challenge is to deny that the sorts of mechanisms involved in cognition need be
highly specialised or inflexible. This theme is familiar from much recent work in which the mind is
conceptualised as a general-purpose computer or a connectionist network. An alternative response,
however, is to argue that though Descartes was right to claim that cognitive mechanisms must be, in a
sense, individually specialised and inflexible, their collective activity can and does result in the sorts of
flexibility that manifest themselves in human thought. This approach is nowhere more apparent than in the
recent and highly influential proposal that our mental architecture is massively modular in structure – that
our minds, including those parts responsible for reasoning and decision making, are largely or perhaps even
entirely composed of highly specialised computational mechanisms or modules.
This paper has a pair of aims. First, I aim to distinguish between some central notions of cognitive
flexibility and clarify the relationship between massively modularity and concerns about cognitive
flexibility. In doing so, I argue that recent disputes over massive modularity are fruitfully construed as
disputes over the extent to which we need posit cognitive mechanisms that possess the sorts of flexibility
possessed by the mind as a whole.
Second, I aim to highlight just how serious Descartes’ Challenge is for advocates of massive modularity. In
doing so, I focus primarily on an intriguing hypothesis defended by Spelke, Carruthers and others,
according to which the mechanisms that subserve natural language processing are largely responsible for
the distinctive flexibility of human cognition. Though I take this language-based proposal to be among the
most plausible attempts to reconcile massive modularity with Descartes’ Challenge, I argue that it is subject
to a range of serious criticisms. Not only does the proposal run contrary to our best extant models of
language production and fail to preserve the commitment to massive modularity, but also it does little to
solve the problems that it was designed to address. I conclude by suggesting that many of the deficiencies
with the language-based proposal are likely to generalise to other attempts to reconcile massive modularity
with Descartes’ Challenge.