There was, however, a powerful anti-rationalist strain in early Christian thought. An extreme form of anti-rationalism calls for the overthrow of rationality altogether. The early Christian writer Tertullian proposed that rational absurdity is itself a reason to believe -- a theme echoed in the nineteenth century by the Danish philosopher S°ren Kierkegaard. There was a certain rationale for this position, namely, that there were aspects of Christian theology that were, and are, hard to believe on ordinary grounds.
The gospels tell us that JesusĘ disciple Thomas doubted JesusĘ resurrection until he saw the master in the flesh, and that Jesus rebuked Thomas for his lack of faith. Faith might be understood as a form of belief which is insensitive to normal standards of evidence. All the evidence was against JesusĘ resurrection, yet Thomas was wrong in failing to believe that it occurred. The general question for the philosophers was to delineate the relation between reason and faith.