The Subject must first be habituated to morality. Before we speak to people of reward and punishment we must first try to develop the indoles erecta. The moral feeling must be enlivened so that the Subject can be swayed by moral Motives. If this fails, we must then have recourse to the subjective incentives of reward and punishment. A man who is rewarded for good conduct will repeat that conduct not because it is good, but because it is rewarded; one who is punished for evil conduct will hate not the conduct but the punishment; he will repeat the evil deed and try with jesuitical craftiness to escape punishment. It is wrong, therefore, for religion to preach that men should avoid doing evil in order to escape eternal punishment; such preaching will lead to wicked conduct, for men will think that they can escape punishment in the long run by a sudden conversion. Nevertheless, reward and punishment can serve indirectly as a means of moral training. If a man does good for the sake of reward, he will gradually acquire the habit of good deeds and will ultimately do them regardless of reward and merely because they are good. Similarly, a man who refrains from doing evil because of fear of punishment will in the long run get accustomed to it and will feel that it is better to leave such things undone. A drunkard who gives up drink because of the harm it does to him will ultimately acquire the habit of sobriety and will come to see that it is better to be temperate than to be a drunkard. Rewards are an even better means for inculcating good conduct than are punishments for inculcating the avoidance of evil. Reward is pleasant, and we can take pleasure in the law which promises a pleasant result provided we act in a certain way; but we cannot love a law which merely threatens punishment. Rewards are thus more in harmony with morality than are punishments. Love is a stronger ground of impulse to performance. It is, therefore, better in religion to begin with reward rather than with punishment.
Punishments must be in keeping with nobility of mind, with indoles erecta. They must not be insulting or contemptuous; otherwise they induce an ignoble type of character.
(Immanuel Kant, Lectures on Ethics, trans. Louis Infield, The Library of Religion and Culture, ed. Benjamin Nelson [New York: Harper & Row, 1963 (first published in 1930)], 56-7)
