I turn more generally to Barth's mature reflections on the relationship between subjectivity, freedom, and rationality. I follow his early dogmatic development, before I narrow in on his work from 1931 onwards. This importantly entails examining the relationship between Barth's speculative theology and the theology of Anselm of Canterbury. Therefore the primary text is Barth's Fides Quaerens Intellectum . This chapter is where I fully develop my argument concerning the speculative theory and practice of Barth's mature theology, and its relation to, for example, Hegel's speculative philosophy.