Søren Kierkegaard (1813-1855) was a Danish philosopher and, so far as I can ascertain, a member of the state church in Denmark, which is a Lutheran church. He was what we might call a Christian critic of Christianity as he understood it. One of his particular concerns was the church-state relationship in Denmark, which he saw as a perversion of Christianity. Although there are likely to be disagreements between his thought and that of the Catholic Church, Catholics probably could find much of value in his writings. The question of Kierkegaard’s religious affiliation may arise because he did offer criticism of Christianity. However, criticism within Christianity by thoughtful writers who are struggling to reconcile what they see to be truth with their understanding of Christianity does not mean that those writers are necessarily not Christian. One Catholic example of this phenomenon is Desiderius Erasmus (ca. 1466–1536), a sixteenth-century Catholic thinker and theologian who verbally jousted with both the Church and with Martin Luther.