What difference does grace make?
It is typical of much theology in the Catholic tradition to frame an understanding of humanity, and of the human being’s relationship to both the world and God, with the help of categories of nature and grace. While in Protestant thought, grace is characteristically conceived as a response to sin, in Catholic thought it is more fundamentally understood as an ‘elevation’ of nature. How more precisely to understand the relationship of grace to nature, however, has itself been a point of contestation within Catholic theology, especially in the last century. This chapter will present the understanding of grace of one particular Catholic thinker, Karl Rahner (1904–1984), setting his understanding of grace both against the background of earlier Catholic positions, and within the context of his broader theological anthropology. Rahner’s theology makes clear how difficult it is to find in a specifically theological concept of grace something that might be fruitful in empirical work – difficult, but perhaps not quite impossible.