After living in Paris for several years, he went to England where he struck up a friendship with Thomas More. With More's support he wrote his best known work In Praise of Folly (Ecomium Moriae 1509) satirizing the political and religious institutions of his time.
Erasmus was neither a fan of scholasticism nor of the philosophical fathers of his day, Plato and Aristotle. For him, in Augustinian tradition, religion must be the servant of faith. It should be direct and simplistic and not convoluted with dogmatic doctrine.
Erasmus' literary works made him the intellectual father of the Reformation. By writing important new Greek and Roman editions of the New Testament, he helped raise questions that would be influential in the Reformation.
It was during this time that Martin Luther's movement began and the struggle between the Catholic and Protestant thought intensified. Erasmus, whose religious ideas were closer to the Protestants, was challenged to take sides. Surprisingly he sided with the Catholic church. Despite his sarcastic criticisms and writings denouncing many of the doctrines and practices of the church, he claimed that he was not criticizing the institutions themselves. He declared that while he was sympathetic to, and respected Luther, he could not condone the violence of the Lutherans. Luther, who in turn had admired Erasmus' superior learning and intellect, had hoped for his support.
When he didn't receive it, Luther felt that Erasmus was being cowardly and avoiding responsibility. Erasmus, however did not want to change doctrine, he merely wanted it reformed.
As Luther's campaign gathered momentum and the unavoidable changes took place, Erasmus began to be bitterly accused of having started the whole sequence of events or "tragedy" of the Reformation. For many years he was both in and out of favor with the Catholic and Protestant factions at different times.
Perhaps Erasmus' most important contribution was that he encouraged people to think and reason for themselves.
He promoted the spread of knowledge that included the works of the great writers of ancient Greece and Rome. He felt that true knowledge would encourage better morality and understanding amongst people.
He did more than any other single person to advance the revival of learning. His literary output was immense and continued throughout his life.
"It is the chiefest point of happiness that a man is willing to be what he is." Desiderius Erasmus