Comparison is held to be one of the central methods of the academic study of religion. While many ostensibly engage in the comparative act, often overlooked is what it actually means to do this. What is comparison? Why engage in it and for what purposes? Can there be such a thing as a valid or invalid comparison? Can comparison itself be compared to anything? This book starts with the premise that while there are good comparisons and bad comparisons, what is common to both is the sheer artificiality of the enterprise and develops an analytical framework for using the method in the context of religious studies. After briefly tracing the history and genealogy of the category, Hughes draws on his own extensive work in Judaism and Islam to argue that comparison can be a useful method, but only under strictly controlled conditions.