G. K. Chesterton (1874-1936) was one of C. S. Lewis' primary mentors in apologetics, and an influence even in his conversion. Novelist, poet, essayist, and journalist, Chesterton was perhaps best known for his Father Brown detective stories. He produced more than 100 volumes in his lifetime, including biographies of St. Francis of Assisi and St. Thomas Aquinas. His Everlasting Man, which set out a Christian outline of history, was one of the factors that wore down Lewis' resistance to Christianity. Chesteron was one of the first defenders of orthodoxy to use humor as a weapon. Perhaps more important was his use of reason to defend faith.