"The flesh is at once man's burden and his temptation. He bears it and yields to it. He must keep watch over it and restrain it, and only obey it in the last resort. Such obedience may be a fault, but it is a venial fault. It is a fall, but a fall onto the knees which may end in prayer. To be a saint is to be an exception;  to be a true man is the rule. Err, fail, sin if you must, but be upright. To sin as little as possible is the law for men; to sin not at all is the dream of angels. All earthly things are subject to sin; it is like the force of gravity."

-- Victor Hugo, Les Miserables