In his chapter, Udo Thiel examines empiricist accounts of inner experience that were developed in the period between Wolff and Kant. During this period, the idea that we are able to experience not only external objects or their properties but also our own mental states and acts developed into attempts at detailed and systematic accounts of this kind of experience. The chapter focuses on two of the most important empiricist thinkers of this period, namely Johann Georg Heinrich Feder and Johann Christian Lossius. Thiel offers an account of their understanding of the nature of inner experience and its function in their philosophical systems. He also explains how their notion of inner experience is related to other central notions, including the notion of Selbstgefühl that Feder introduced into the philosophical debate. The chapter ends with an account of how Kant’s notions of inner sense and apperception relate to the notions of inner sense and Selbstgefühl in Feder and Lossius.