Given the shared conviction about the indubitability of I-consciousness, this book analyses the repeated philosophical adventures over centuries to understand its enigmatic character. Philosophers - votaries of the self or the no-self theories - who tried to unveil the phenomenon ofI-consciousness have employed various explanatory strategies but have not reached any unanimous conclusion. Hosts of psychological, epistemological, linguistic, metaphysical, phenomenological, ethical, even religious interpretations are available. While the major focus is on the Upanisadic and the Buddhist traditions, this volume also examines Western philosophical traditions. It also discusses the expository and the polemical aspects present in the theory-making endeavours recorded in the Indian sources. Based on this rich material, the bookanalyses an array of concerns closely related to the central theme of I-consciousness in a cross-cultural philosophical context. This study leads to the overwhelming recognition of the fact that the phenomenon of I-consciousness that is existentially closest to us is furthest from ourunderstanding, thus an enigma, as mentioned in the title.