This is the penultimate draft of a book chapter to appear in: D. Barrett & P. McNamara (eds), The New Science of Dreaming. E stport, CT: Praeger Imprint/ Greenwood Publishers. The Philosophy of Dreaming and Self-Consciousness: What Happens to the Experiential Subject during the Dream State? Jennifer Michelle Windt and Thomas Metzinger Dreams have been a topic of philosophical inquiry ever since Aristotle’s treatise On Dreams and throughout the history of Western thought (Dreisbach 2000). Probably the most famous philosophical approach to dreaming is the problem of dream skepticism, which Descartes discussed in the first Meditation. Here, Descartes famously argued that because of the realistic quality of sensory experience during the dream state, it would never be possible to distinguish dreaming from wakefulness on empirical grounds alone (Descartes 1911/1642). In the 20 th century, however, interest in the epistemological problem of how to determine whether one is dreaming or awake was reduced considerably by an anti-Cartesian argument advanced by Norman Malcolm (1956; 1959). Arguing that reports about dreaming are not publicly verifiable even in principle, Malcolm asserted that the notion of conscious awareness in sleep was contradictory on purely logical grounds. “If a person is in any state of consciousness it logically follows that he is not sound asleep” (Malcolm 1956, p. 21)—hence, according to Malcolm, dreams are not experiences at all (see also Dennett 1976; for a discussion see Metzinger 1993, pp. 146ff., pp. 194ff., and pp. 241ff.; Revonsuo 1995, pp. 36ff.). Today, based on a more differentiated understanding of both the phenomenological and the neurophysiological features of dreaming, it is possible to give a relatively straightforward and affirmative answer to the question of whether dreams are conscious experiences occurring in sleep. At the same time, these new insights into the nature of dreaming require a more nuanced perspective, which is capable of explaining the subtle