  In this paper, a candidate for pregeometry, Ponzano-Regge spin networks, will
be examined in the context of the pregeometric philosophy of Wheeler. Ponzano
and Regge were able to construct a theory for 3-dimensional quantum gravity
based on 3nj-symbols, obtaining the path integral over the metric in the
semiclassical limit. However, extension of this model to 4-dimensions has
proven to be difficult. It will be shown that the building blocks for
4-dimensional spacetime are already present in the Ponzano-Regge formalism
using a reinterpretation of the theory based on the pregeometric hypotheses of
Wheeler.
