Doctrine in Development examines the doctrine of the imputation of Christ’s active obedience with a focus on the thought of Johannes Piscator. Challenging earlier scholarship that regarded the doctrine as clearly present in the Reformers, Heber Campos shows how Piscator’s exegetical and theological arguments generated responses that brought together several other doctrines to support the imputation of Christ’s active obedience in a way that Reformed theologians had not previously done. Viewing Piscator’s objections to the imputation of Christ’s positive righteousness as a turning point in the Reformed understanding of active obedience, Campos highlights the process of doctrinal development regarding Christ’s satisfaction.