Edouard Machery

The second volume is devoted to issues of compositionality that arouse in the sciences of language, the investigation of the mind, and the modeling of representational brain functions. How could compositional languages evolve? How many sentences are needed to learn a compositional language? How does compositionality relate to the interpretation of texts, the generation of idioms and metaphors, and the understanding of aberrant expressions? What psychological mechanism underlies the combination of complex concepts? And finally, what neuronal structure can possibly realize a compositional system of mental representations?

Folk theories—untutored people’s (often implicit) theories about various features of the world—have been fashionable objects of inquiry in psychology for almost two decades now (e.g., Hirschfeld and Gelman 1994), and more recently they have been of interest in experimental philosophy (Nichols 2004). Folk theories of psy- chology, physics, biology, and ethics have all come under investigation. Folk meta- physics, however, has not been as extensively studied. That so little is known about folk metaphysics is unfortunate for (at least) two reasons. First, folk metaphysics is almost certainly implicit, and it is likely to be our default way of thinking about metaphysical problems. Moreover, one’s metaphysical commitments can have pro- found consequences—in scientific, religious, and ethical contexts, for example. Thus, folk metaphysics ought to be dragged out into the open and exposed to criticism. As Peirce eloquently remarked (1994, 1.129; see also 1994, 7.579)