Iustitia Fidei: The Development of Augustine’s Account of Justification by Faith

This dissertation considers how Augustine understood justification by faith in light of his theology of faith, as in the Pauline phrase iustitia fidei, “the righteousness of faith.” Though Augustine’s understanding of the nature of justification as “making righteous” has been examined and largely acknowledged since the Reformation, this dissertation proposes a re-framing of faith as the vital center to Augustine’s doctrine. Proceeding chronologically from 390-430, it argues that Augustine’s understanding of the iustitia fidei expanded over time.

What is the iustitia fidei? First, faith receives divine instruction, expresses trust in grace, and conforms one to Christ’s humility. Justification is therefore ascribed to a trusting, Christoform faith; righteousness consists in charity, but it abides in faith. Second, following Ambrose, Augustine attributes justification to baptism, but he does so by analyzing the desires of faith. By faith, the catechumen first hopes for baptismal grace and then in baptism receives the love of the Holy Spirit. Third, following the different uses of faith in Scripture, Augustine distinguishes the bare assent that Christ is God (credere Christum) from believing in Christ (credere in Christum), meaning to long for incorporation into Christ, to love by believing. Augustine thus offers multiple ways of interpreting faith and justification: as faith alone, which he considers inadequate to justify; as the way to hope and charity, and thus justifying by anticipation; and as a fundamentally justifying orientation of the soul.

This dissertation contributes to the study of Augustine as a theologian whose thought expanded and deepened with time, to Augustine’s theology of faith as a virtue, and to his complex contributions to the history of justification.