Supersymmetry, supergravity, superstring phenomenology

In the present talk, I shall concentrate on the problem of the quadratically divergent Higgs masses (with supersymmetry as a potential cure) and the problem of the non-renormalizability of gravity with a possible solution given by superstring theory. In all these examples we see a quest for renormalizability and finiteness; a better theory is a theory with less divergences. Given this basic assumption, let us now discuss the standard model in more detail. Certainly, this model is not the final model of the world since it contains too many free parameters (masses, mixing angles, coupling constants). Also the more fundamental questions about the origin of the gauge group SU(3)xSU(2)xU(1) and the reason for the existence of three families of quarks and leptons cannot be answered