 Augustine’s most famous anti-skeptical argument is what is commonly called his “cogito-like” argument because it is similar to (and probably inspired) the Cogito of Descartes (Matthews 1992; Menn 1998; Fuchs 2010). Like Descartes’, Augustine’s cogito establishes an area immune to skeptical doubt by inferring from my awareness of my own existence the truth of the proposition “I exist”. Even if I were in error in uttering this proposition, it would still be true that I, who am in error, exist (De civitate dei 11.26: si enim fallor, sum; for the exact reconstruction of this argument cf. Horn 1995: 81–87; Matthews 2005: 34–42). The argument does not yet appear in Contra Academicos but is easily recognized as a development of the argument from subjective knowledge (Contra Academicos 3.26); Augustine considers it a valid refutation of skepticism from his earliest (De beata vita 7) to his latest works (De trinitate 15.21; for further attestations see Soliloquia 2.1; De duabus animabus 13; De libero arbitrio 2.7; De vera religione 73; Confessiones 7.5; 13.12). The scope of the argument in Augustine is both wider and narrower than in Descartes. The Augustinian cogito lacks the systematic importance of its Cartesian counterpart; there is no attempt to found a coherent and comprehensive philosophy on it. On some occasions, however, it works as a starting point for the Augustinian ascent to God (De libero arbitrio 2.7, where the ascent leads to an understanding of God as immutable truth and wisdom; for a condensed version, cf. De vera religione 72–73, where Augustine even makes supra-rational Truth the source and criterion of the truth of the cogito itself). The most impressive example is the second half of De trinitate. Here the attempt to reach a rational understanding of the mystery of the Trinity by means of an inquiry into the structure of the human mind starts with an analysis of the mind’s inalienable self-love and self-awareness (see  6.2 The Human Mind as an Image of God;  Augustine does not, however, claim that the mind’s certainty about itself entails a similar certainty about the nature of God). Augustine’s cogito argument is not limited to epistemology but can also be employed in an ethical context because it proves not only my existence and my thinking (and, by implication, my being alive) but also my loving and willing. I am as certain that I will as I am certain that I exist and live, and my will is as undeniably mine as is my existence and my life. Therefore, my volitions are imputable to me, and it is I who am responsible for my choices (and not some evil substance present in my soul but foreign to my own self, as, on Augustine’s interpretation, Manichean dualism would have it; cf. De duabus animabus 13; Confessiones 7.5; De civitate dei 5.10).