 Should these results lead us to believe that singularities are real? Many physicists and philosophers resist this conclusion. Some argue that singularities are too repugnant to be real. Others argue that the singular behavior at the center of black holes and at the beginning (and possibly the end) of time indicates the limit of the domain of applicability of general relativity. Some are inclined to take general relativity at its word, however, and simply accept its prediction of singularities as a surprising but perfectly consistent account of the possible features of the geometry of our world. (See Curiel 1999 and Earman 1995, 1996 for discussion and comparison of these opposing points of view.) In this section, we review these and related problems and the possible responses to them. 