This is a comprehensive analysis of the thought of Ignacio Ellacuria, the Jesuit philosopher-theologian martyred for his work on behalf of Latin America's oppressed peoples. The author shows how Ellacuria effectively integrated philosophy, history, anthropology, and sociopolitical analysis into his theological reflections on salvation, spirituality and the church to create an original contribution to liberation theology. It explains how Ellacuria bases theology in a philosophy of historical reality - the "ground beneath the cross". Placing Ellacuria's thought in the context of historical trends within the Roman Catholic Church, paricularly Vatican II and the rise of liberation theology in Latin America, it argues that Ellacuria is a significant voice in contemporary Catholic theology.