"My general meaning touching the three virtues of which I have spoken will now, I hope, be sufficiently clear. They are all three paradoxical, they are all three practical, and they are all three paradoxical because they are practical. it is the stress of ultimate need, and a terrible knowledge of things as they are, which led men to set up these riddles, and to die for them. Whatever may be the meaning of the contradiction, it is the fact that the only kind of hope that is of any use in a battle is a hope that denies arithmetic. Whatever may be the meaning of the contradiction, it is the fact that the only kind of charity which any weak spirit wants, or which any generous spirit feels, is the charity which forgives the sins that are like scarlet. Whatever may be the meaning of faith, it must always mean a certainty about something we cannot prove. Thus, for instance, we believe by faith in the existence of other people."