Chapter 25 considers the 1547 Tridentine Decree on Justification. This document is widely regarded as one of the most significant statements on the doctrine of justification. It set out a full exposition of the Catholic position, rather than simply rejecting opinions regarded as unacceptable. The Council saw its task as ‘expounding to all the faithful of Christ the true and sound doctrine relating to justification’, not simply identifying what they considered to be the errors of Protestantism. This chapter consists of four sections. The first considers the Decree’s teaching on the first stage of justification, which includes a strongly transformist concept of justification, and a rejection of any idea that justification can be said to be merited. It also firmly links justification with the sacrament of baptism. The second considers its teaching on the second stage of justification, dealing with the way in which believers increase in righteousness. The third deals with the restoration of justification through the sacrament of penance. Finally, the canons of the decree, dealing with views that the Council regarded as unacceptable, are noted and their significance assessed.