Abstract
III the usual constructivist view of learning mathematics the student is engaged in the· active process of
constructing meaning for instructionally given target concepts. Cobb, Yackel, and Wood (1992) and others
propound an alternative view, social constructivism, which treats mathematics both as an individual
constructive activity. and as a social practice. On this view, learning operates as an individual cognitive
action (construction of interpretations) "iade compatible by social interaction with the colleCtive
interpretations of mathematically acculturated practitioners. One argument used by Cobbet al against.
standard forms of constructivism is that they commonly rely on an essentialist theory of knowledge. In this
paper, however. it is argued that the notions of interpretation, meaning, and construction crucial to the
position of Cobb et alalsodepend on essentialist theories afknowledge. Approaches to validating this claim
. are made in three lines of inquiry drawing upon notions of theory of practice, philosophy of language, and the
science of signs or semiotics. Important parallels between these discussions, and between certain·
poststructuralist formulations are noted in the process of argument. An outline of elements of a new
postconstructivist theory of learning emerges. A touchstone for these ideas is provided by Lave and Wenger's theory of learning as legitimate peripheral participation; allusions to this theory are made throughout
the paper, although no direct study of it, or its relation to the theory figured here is attempted,