This work examines the theme of universality in the thought of the Protestant theologian Wolfhart Pannenberg and the Roman Catholic theologian Karl Rahner. Pannenberg's critical-rationalist approach and Rahner's transcendental method are examined as methodological foundations for theology as universal science. The respective anthropologies and doctrines of God of the two theologians are also compared. Both theologians develop a similiar apologetic praxis in their dialogues with modern science, atheistic worldviews, and non-Christian religions. This 'common' apologetic, it is argued, has its foundation in the concept of the universality of theology which both thinkers develop methodologically, albeit in very different ways. The programs of both theologians form important starting-points for doing theology within the dialogical context of the modern world.