Thought experiments are performed in the "laboratory" of the mind. Beyond this metaphor, it is difficult to define just what these remarkable devices for investigating nature are, or how they work. Although most scientists and philosophers recognize the importance of thought experiments, "The Laboratory of the Mind" is the only full-length study of their nature and function. Beginning with Galileo's argument on falling bodies, James Robert Brown describes numerous examples of the most influential thought experiments from the history of science. He provides a thorough introduction to the subject, and makes the provocative claim that some thought experiments should be understood in the same way that platonists understand mathematical activity: as an intellectual grasp of an independently existing abstract realm. The book concludes with chapters on the nature of Einstein's work and on the interpretation of quantum mechanics which stand as a test of the author's central claims. Now available in paper, "The Laboratory of the Mind" provides a clear and well-structured discussion that will be of great interest to both philosophers of science and scientists.