In this short article we introduce the mathematical framework of the
principle of the fermionic projector and set up a variational principle in
discrete space-time. The underlying physical principles are discussed. We
outline the connection to the continuum theory and state recent results. In the
last two sections, we speculate on how it might be possible to describe quantum
gravity within this framework.Comment: 18 pages, LaTeX, few typos corrected (published version
