The Catholic Reformation was the intellectual counter-force to Protestantism. The desire for reform within the Catholic Church had started before the spread of Luther. Many educated Catholics had wanted change - for example, Erasmus and Luther himself, and they were willing to recognise faults within the Papacy.
During the Cl5, society was changing. The Renaissance taught people to question and to challenge the norm. The Catholic Church hierarchy failed to change with it and the organisation of the Church appeared dated. Others had tried to bring forward Catholic doctrine.
In the Cl3, St. Thomas Aquinas published “Summa Theologica” - a fusion of Christian belief and Aristotlean philosophy. He saw Man as essentially rational and able to see right from wrong. Man could steer a course to salvation but needed guidance from the Church and state. St. Thomas was optimistic about Man. His beliefs were known as Thomism. In the C16, Thomism was still a strong philosophy. Cardinal Cajetan, Luther's opponent at Augsburg in 1518, claimed that Thomism was still relevant to society and Thomism made a strong contribution to the Catholic Reformation.
But Augustinian beliefs were still strong and alive in Catholic centres of learning. St. Augustine believed the opposite to St. Thomas; he claimed that Man was corrupt and fallible. Augustine's beliefs had a great impact on Luther.
Francisco de Suarez and Luis de Molin (both Jesuits) both tried to bridge the gap between Thomism and Augustinianism by claiming that Man had freedom of choice but ultimately God was omnipotent.
Some Catholic reformers were also influenced by late Medieval mysticism such as Master Eckhardt and Thomas a Kempis. In France, Lefèvre d'Etaples published translations of the mystic writers. The Dutch Jesuit Peter Canisius was greatly influenced by mystics. He founded Jesuit colleges all over Germany.
Many old monastic orders had sunk to levels of unacceptable standards. However, some had made the effort (such as the Carthusians) to maintain very high standards of discipline and learning. The Observants observed the original strictness and poverty of the Dominicans and Franciscans. The Observants struggled with the Conventuals who wished to see things left as they were.
The Catholic Reformation relied on individuals. Cardinal Ximenes from Spain tightened clerical discipline and encouraged scholarship at schools and universities.
Matteo Giberti was an early member of the Oratory of Divine Love founded in Rome in 1517 to foster good works in everyday life. He was also the secretary to Clement VII.
Gian Pietro Caraffa (later Paul IV) helped to find the Theatines in 1524 - an order of priests working within the community but living in monastic austerity.
These were men of great intellect and thought who never wavered in adherence to the Catholic Church. All the above men wanted a more spiritual and less worldly religion.
Between 1520 and 1530, there was a lot of common ground between the Protestants and the Catholics. But the emphasis was put on the differences not the similarities. By 1550, the gap was unbridgeable and as it widened the policy of the Catholic Church was to become more aggressive.
In 1545, the Council of Trent went out of its way to highlight the differences and Augustinianism became rejected out of hand because it was too near the “Protestant belief”.
The Catholic Reformation had a lot of widespread appeal to intellects. The Counter-Reformation did not.