Representation is a triadic relationship: A (the agent) represents B (the
principal) before C (the third party), where A, B and C are different persons.
In its pure form, the agent cannot bind the principal to any agreement with the
third party without the principal’s express consent. In political history,
representatives of the estates (nobility, clergy, and burghers) started out on this
basis. They represented certain classes of people in the assemblies convoked
by the king but could not make agreements with him that would bind their
principals.