Leap of faith

A Leap of faith commonly refers to believing something that cannot be touched or proved by science, for which there is no evidence. Usually the term is attributed to Søren Kierkegaard, even though he never really used it. According to Kierkegaard, such a leap involves circular reasoning, because a leap is made by faith.
A leap of faith is commonly associated with religious belief because many religions consider faith to be an essential element of piety.