  In this paper we formulate Maxwell and Dirac theories as an already unified
theory (in the sense of Misner and Wheeler). We introduce Dirac spinors as
"Dirac square root" of the Faraday bivector, and use this in order to find a
spinorial representation of Maxwell equations. Then we show that under certain
circunstances this spinor equation reduces to an equation formally identical to
Dirac equation. Finally we discuss certain conditions under which this equation
can be really interpreted as Dirac equation, and some other possible
interpretations of this result.
