 This is all in accord with the so-called Past Hypothesis—the need to postulate that the universe must have started in an extremely special, low-entropy state—if one admits the existence of generalized gravitational entropy. It has long been held by many physicists and philosophers that the Past Hypothesis is the only way to preserve the validity of the Second Law of thermodynamics over cosmological scales (Albert 2000). Many philosophers and physicists have balked at the Past Hypothesis, however, claiming it is explanatorily vacuous or that it itself raises further difficult questions, such as why the universe should have started in such a “special and unlikely” state at all. (See Albert 2000, Earman 2006, Callender 2010, and Wallace 2010 for discussion of many of these issues, from competing perspectives.) Penrose (1979) put forward the intriguing possibility that his Conformal Curvature Hypothesis itself could point to an answer to all these questions: the seemingly required “specialness” of the state of the early universe may have a dynamical explanation in a more fundamental theory of quantum gravity. As intriguing as that possibility may be, it by no means has universal support. Wald (2006a), for example, gives compelling arguments against the possibility that the low entropy of the early state of the universe could have a dynamical origin. 