Religious visions of reward-and-punishment in the afterlife fall into two basic categories. One category consists of what I will call “precipice” regimes, in which there are just two afterlife outcomes: heaven and hell. If you commit more than some threshold number of sins (possibly just one), you go to hell; otherwise you go to heaven. Many Protestant faiths seem to fall in this category. The other category consists of what I will call “gradient” regimes, in which there is a range of afterlife outcomes lying between sheer torment and pure bliss. In Mormonism (or so I am told), there are many different levels of heaven, and which one you reach depends on your behavior in this life. In Catholicism, how much you’ve sinned in this life determines the amount of time you spend in Purgatory. In Hinduism, your behavior now determines what kind of creature or class of person you’ll become upon resurrection.
Assuming that afterlife regimes are designed to deter bad (sinful) behavior, what beliefs about people’s preferences and choice mechanisms are implied by each type of regime? Let’s say you’re a deity who currently presides over a gradient regime, and you’re considering a switch to a precipice regime. Doing so will induce some individuals, who would have committed some number of sins under a gradient regime, not to commit any sins at all (if the hell-threshold is one sin) or to commit just under the threshold number of sins. That’s the upside. The downside is that individuals who have already passed the threshold will have no incentive to behave well. Since they’re already going to hell, they might as well commit all the sins they want. In addition, people sufficiently far below the threshold will have no incentive not to commit additional sins (unless there’s uncertainty about where the threshold lies). Thus, there’s a trade-off involved in the choice of regimes, and individual preferences and choice mechanisms will determine which regime is the more effective in deterring sins.
I hypothesize that precipice regimes are appropriate if you think that the utility of committing sins is relatively constant over time, whereas gradient regimes are appropriate if there will be occasional opportunities for sinning that are of such high utility that they cannot be resisted by many people regardless of punishment. The downside of a precipice regime is particularly high in the latter case, because many people will succumb to large temptations and then, figuring their souls are lost anyway, commit many more transgressions. On the other hand, if there are few super-sized temptations and many small-to-medium ones, the precipice regime might be more successful in deterring them, because people under a gradient regime will balance each additional sin against the minor reduction in afterlife status that will accompany it, and some medium-sized sins will be enjoyable enough to be worth it.
A precipice regime might also be more effective in preventing addictive sins, defined as sins with increasing marginal utility of commission: the more of the sin you’ve committed, the greater is your desire to do it again. Under a gradient regime, people who commit their first addictive sin will have an increasing inclination to do so repeatedly (unless the gradient becomes steeper and steeper as the number of sins rises). A precipice regime could not prevent the additional sinning, but it would stand a better chance of inducing people not to commit the very first sin.
Next up: mixed regimes, in which some sins are treated with a gradient and others with a precipice.