The talk will focus on classical and quantum stability in putative landscapes. After outlining the general issues, we will provide an analytic understanding of results of Greene, Weinberg et al. regarding quantum tunneling. We will then turn to classical questions, motivated particularly by work of McAlister et al. We will stress the role of correlations among couplings in low energy effective theories with many fields. In the supersymmetric case, we will argue that stability may not be a severe constraint. We will then draw some general conclusions.