In this survey article we explain a few ideas behind the framework of
the fermionic projector and summarize recent results which clarify the connection
to quantum field theory. The fermionic projector is introduced, which describes the
physical system by a collection of Dirac states, including the states of the Dirac sea.
Formulating the interaction by an action principle for the fermionic projector, we
obtain a consistent description of interacting quantum fields which reproduces all
results of perturbative quantum field theory. Moreover, we find a new mechanism for
the generation of boson masses