A formulation of spinor analysis in space-time is given in terms of smooth sections of a real Clifford bundle. Its relation to the two-component complex calculus for spinor components is elucidated. Treating spinors in terms of inhomogeneous differential forms carryingPIN 3,1 andSPIN 3,1 representations enables the discrete covariances of the Maxwell-Dirac system to be induced naturally from smooth isometries of the space-time metric. Attention is drawn to the distinction between the Dirac and Kahler equations in curved space when expressed in this geometric formulation.