Historian Diarmaid MacCulloch, in his book The Reformation, A History noted that through all the slaughter of the Reformation era emerged the valuable concept of religious toleration and an improved Catholic Church[153] which responded to doctrinal challenges and abuses highlighted by the Reformation at the Council of Trent (1545–1563). The council became the driving-force of the Counter-Reformation, and reaffirmed central Catholic doctrines such as transubstantiation, and the requirement for love and hope as well as faith to attain salvation.[154] It also reformed many other areas of importance to the Church, most importantly by improving the education of the clergy and consolidating the central jurisdiction of the Roman Curia.[7][154][155]