All punishment, once applied, loses a part of its influence by the very fact of its application. What lends it authority, what makes it formidable, is not so much the misery that it causes as the moral discredit implied in the blame that it expresses. This feeling of moral sensitivity that stands guard against misdeeds is one of the most delicate of sentiments. It is not strong, it is not complete in itself, it lacks its full power of influence except among those for whom it has lost nothing of its original purity. We often say that the first offence always leads to others. This is because, once we have felt it, we are less sensitive to this shame. Punishment has this very great limitation of clashing with one of the chief resources of the moral life, and thus reducing its own efficacy in the future. It retains all of its force only when it simply constitutes a threat.