  Since the late 1980s, and especially the late 1990s, a variety of writers working in philosophy of mind have focused on the fundamental character of consciousness, ultimately a phenomenological issue. Does consciousness always and essentially involve self-consciousness, or consciousness-of-consciousness, as Brentano, Husserl, and Sartre held (in varying detail)? If so, then every act of consciousness either includes or is adjoined by a consciousness-of-that-consciousness. Does that self-consciousness take the form of an internal self-monitoring? If so, is that monitoring of a higher order, where each act of consciousness is joined by a further mental act monitoring the base act? Or is such monitoring of the same order as the base act, a proper part of the act without which the act would not be conscious? A variety of models of this self-consciousness have been developed, some explicitly drawing on or adapting views in Brentano, Husserl, and Sartre. Two recent collections address these issues: David Woodruff Smith and Amie L. Thomasson (editors), Phenomenology and Philosophy of Mind (2005), and Uriah Kriegel and Kenneth Williford (editors), Self-Representational Approaches to Consciousness (2006).