  In this paper we argue that d-wave symmetry is a general consequence of
superconductivity driven by repulsive interactions. Van Hove (or flat band)
effects, deriving from the two dimensionality of the $CuO_2$ plane are
important in stabilizing this state. By extending the original Kohn-Luttinger
picture to a 2 D lattice, we find that the screened Coulomb term has important
wave vector structure which leads to $d_{x^2-y^2}$ superconductivity
