"Consciousness is what makes the mind-body problem really intractable." So begins Thomas Nagel's classic 1974 essay "What is it Like to be a Bat?" Nagel's essay initiated the now widespread attention to consciousness as a central problem for philosophy, psychology, and neuroscience; it also influenced the recognition of the consciousness of nonhuman creatures as an important subject of study. Nagel argued that the essential subjectivity of conscious experience—what it is like for the creature undergoing it—means that reductionist theories of mind, which attempt to analyze it in physical terms, can never succeed. It follows that the physical sciences cannot provide a complete description of reality, and that the physical conception of objective reality must be transcended if science is going to comprehend the mind.

This edition reissues this classic and widely influential article on its fiftieth anniversary, along with a new preface discussing the origins and influence of the essay, as well as "Further Thoughts: The Psychophysical Nexus," a supplementary essay which describes Nagel's later thoughts about how to respond to the problem posed by "What Is It Like to Be a Bat?"