Analyzing and comparing the doctrines of justification held by a legendary nineteenth-century Catholic, John Henry Newman, and an Italian hero of the Reformation, Peter Martyr Vermigli, this book uncovers abiding opportunities, as well as obstacles at the Catholic-Protestant divide. These earnest scholars of the faith were both converts, moving in opposite directions across that divide, and, as a result, speak to us with an extraordinary degree of credibility and insight. In addition to advancing scholarship on several issues associated with Newman’s and Vermigli’s doctrines, and illuminating reasons and attendant circumstances for conversion across the Tiber, the overall conclusions of this study offer a broader range of soteriological possibilities to ecumenical dialogue among Roman Catholics and Reformed Protestants by clarifying the common ground to which both traditions may lay claim.