 A common hope is that when quantum effects are taken into account in the vicinity of such extreme conditions of curvature where singularities are predicted by the classical theory, the singular nature of the spacetime geometry will be suppressed, leaving only well behaved spacetime structure. Advocates of various programs of quantum gravity also argue that in such a complete, full theory, singularities of the kinds discussed here will not appear. Recent important work by Wall (2013a, 2013b) shows that these hopes face serious problems. We pick up these issues below, in  section 5.4.4  and  section 6.3  respectively, for it is in those contexts that many of the explicit debates play out over the limits of general relativity. 