Nagel is probably most widely known within the field of philosophy of mind as an advocate of the idea that consciousness and subjective experience cannot, at least with the contemporary understanding of physicalism, be satisfactorily explained using the current concepts of physics. This position was primarily discussed by Nagel in one of his most famous articles: "What is it Like to Be a Bat?" (1974). The article's title question, though often attributed to Nagel, was originally asked by Timothy L.S. Sprigge. The article was originally published in 1974 in "The Philosophical Review", and has been reprinted several times, including in "The Mind's I" (edited by Daniel Dennett and Douglas Hofstadter), "Readings in the Philosophy of Psychology" (edited by Ned Block), Nagel's "Mortal Questions" (1979), "The Nature of Mind" (edited by David M. Rosenthal), and "Philosophy of Mind: Classical and Contemporary Readings" (edited by David J. Chalmers).