 Third, in the process of asking whether we can have knowledge of God it makes sense to distinguish between kinds of knowledge (sensory, rational, by testimony, etc.). If we know God, then we do so via one of the kinds of knowledge. This becomes a standard feature of discussions of skepticism. Philosophers go through the different kinds of knowledge that are conceivable, and examine them in turn. In Augustine as well as later authors, this includes mathematical knowledge (Nawar 2022). Though Sextus wrote on geometry and arithmetic, questions about knowledge in mathematics do not shape Hellenistic debates between skeptics on the one hand and Epicureans and Stoics on the other hand. Fourth, Augustine conceives of what he calls ‘inner knowledge.’ He envisages a skeptical scenario. Suppose we have no sensory knowledge, no rational knowledge, and no knowledge of testimony. We still know that we think, love, judge, live, and are (De Trinitate 15.12). In the City of God 11.26, Augustine uses his well-known phrase “si enim fallor, sum” (even if I err, I am). That is, Augustine suggests that we have knowledge of our mental acts (cf. Nawar 2022 on Augustine’s concern with self-knowledge). However, Augustine does not consider these pieces of knowledge foundational. While he points to them when he discusses the challenges of Academic skepticism, he does not systematically build upon them in refuting skepticism about sense perception, rational knowledge, and knowledge of testimony. Rather, he refutes skepticism by stating that God created us and the things that are known to us; God wanted these things to be known to us (De Trinitate 15.12). In later epistemology, the idea of the turn into one’s mind and an introspective access to one’s mental acts becomes a secular idea. Augustine is a transitional figure in the philosophy of mind, and thereby re-conceives skepticism. By focussing on a gap between ‘what is in the mind’ and the world outside, he as it were invites external world skepticism (Vogt 2014a). But Augustine is concerned with the path to God: the mind turns into itself and from there it moves further, toward God (e.g., Confessions 7. 17,23).