"Sacrifice has always been regarded as the most convincing proof of loyalty; and its most common form involves a foregoing of the use of some organic function, as in the case of celibacy or fasting. Of at least equal significance, however, is a sacrifice of the use of reason - credo quia impossibile - and the more incredible the assertion, the stronger the proof of the devotion manifested by its acceptance. The Catholic theologians are quite explicit about this, and openly say that by affirming what to the human reason appears absurd, a believer proves his love for God. Although they are never so frank about it, the secular sects make similar demands."