What are the roles of doubt and scepticism in the religious landscape of the ancient Mediterranean? How is doubt expressed within a specific religious community, and what reactions does it provoke? How does ''insider doubt'' differ from the sceptical attitude of outsiders? Exploring these questions with respect to a wide range of religious contexts and topics (including early Christianity, Greco-Roman religions, Egyptian religions, astrology, and magic), the essays in this volume confirm the thesis that doubting one's own religious tradition is not simply a ''Western'' post-Enlightenment phenomenon. On the contrary, ancient religions offered opportunities and contexts wherein aspects of doubt are not just tolerated but accepted; moreover, doubt and scepticism concerning certain religious ideas or aspects of belief also motivated creative reinterpretation of those ideas.