Attempts to account for the significance of materiality for cognition should pay special attention to the vehicle in which meaning and information are embedded. Distributed cognition pays surprisingly little attention to conceptualizing the distinction between transitory and durable representations. I use the example of David Kirsh’s research to argue that the bias toward defining cognitive extensions in terms of stable objects existing in space leads to their reification. The aim of this paper is to indicate the sources of reification and (...) argue that implicit ambiguity emerges toward external representations due to an over-reified view of cognitive extensions. (shrink)