This book offers a solution for the problem of structure and agency in sociological theory by
developing a new pair of fundamental concepts: metric and nonmetric. Nonmetric forms arising
in a crowd made out of innumerable individuals correspond to social groups that divide the
many individuals in the crowd into insiders and outsiders. Metric forms correspond to congested
zones like traffic jams on a highway: individuals are constantly entering and leaving these
zones so that they continue to exist even though the individuals passing through them change.
Building from these concepts we can understand ¿agency¿ as a requirement for group identity
and group membership thus associating it with nonmetric forms and ¿structure¿ as a
building-up effect following the accumulation of metric forms. This reveals the contradiction
between structure and agency to be a case of forced perspective leaving us victim to an
optical illusion.
