No one today seriously believes that God the irascible will jump ex machina and smite those you violate his law. In their honest moments, few theists believe in heaven, hell, or Pascal’s wager.
It is, in other words, heroically difficult to expect that these commandments are actually going to be enforced by God. The absence of a credible enforcement mechanism then makes it precisely costless to ignore them. So why should a self-interested agent care in the least ?
This argument is, by the way, equally destructive to secular formulations: Lacking an enforcement mechanism, Plato’s moral truths are left as irrelevant as God’s commandments.
Now the only reason why a self-interested agent should care about divine commandments is this: That she has to share her living space with people who in the course of talking a lot about ‘God’ make it their business to enforce these supposedly divine commandments. With that, however, we have left the realm of the divine. We are back on earth to the usual game pitting various tribes against each other: Each tribe trying to enforce its own preferred set of values, some with rhetorical appeals to the divine, some – mercifully – without.
It is not surprising when people believe their own preferred set of values to be endorsed by their own preferred deity. What is surprising is when they believe that this should convince anybody else. For anyone not already part of the same small religious subtribe as the speaker, for anyone who does not already share the speaker's exact set of values, ritual invocations of the clan's ancestral deity must be as meaningless as a dance around a tribal totem.
The only part of morality that dies when God dies is a certain form of hollow rhetoric. If there is a rational basis for fear, it is the fear of those addicted to the rhetoric of facing the world without it.
If human reality really were structured to favour moral behaviour, a self-interested agent would be motivated to behave morally in order to buy himself success in a world that demands it. As a matter of broad averages, it may even be correct to say that generous strategies outperform strategies of playing stingy and nasty. As a matter of broad averages you may indeed have to behave morally in order to get along in this world. There is, however, one glaring problem: It is frighteningly easy to think of cases where virtue is obviously not rewarded in this life. Frighteningly easy to think of scenarios where the virtuous choice is costly, and the alternatives are easy, riskless, and without any visible drawbacks. The obvious strategy for a self-interested agent is then this: Give the appearance of moral behaviour in the large majority of situations where is pays, and turn your back on moral behaviour as soon as it doesn’t. We may even grant that an interest in giving the appearance of moral behaviour would likely lead to more than just the appearance. The most effective way of faking sincerity may indeed be sincerely trying to be sincere. Over time, performance could become (indistinguishable from) identity. The glaring exceptions, however, won’t go away; we still haven’t been given any reason whatsoever for a perfectly self-interested agent to play nice in certain extreme situations.
Game theorists strip out the ambiguities of real life in order to present us with choices in their starkest possible form. These scenarios are highly artificial, but instructive nonetheless.
The scenario we want to examine here is this: the opportunity presented to a person of getting away with an undetectable crime.
Let’s look at some reasons for not committing a prefect crime that could convince a perfectly self-interested agent. Strictly speaking, no such reason exists. However, there are still ways in which a perfectly self-interested agent could come not to commit a riskless defection without having violated the imperative of self-interest maximisation.
Whatever people may say about their intentions in a perfect crime scenario is, by definition, unverifiable. It is, as far as their opposites are concerned, an uncallable bluff.
And if we have no way of distinguishing Type 1 from Type 4, then Type 2 may after all be the safest bet. (Type 2 behaviour could itself be a cover for Type 3, but this would not be a serious deception. Where Type 3 is a full warning, Type 2 signals half a warning. The real cost – renouncing the safety of Type 1 – has been paid, either way.)
Saying that Type 2 reactions are best is the equivalent of rejecting the usefulness of any absolutist moral prescriptions. What could be the use to you of getting me to mouth “I would not commit the perfect crime” ? Would a firm answer, returned without hesitation or other subconscious signals, be unfakeable ? Would it tell you anything ?
There does remain one way for the innocents to fight back, besides charm: Making their talk less cheap. Doing nice things to prove they really mean to be nice. Yet however many good works you perform, no amount is going to be a fool-proof signal to separate Type 1 from Type 4. Provided then both Type 1 and Type 2 perform equal amounts of good works, we are back to preferring Type 2 (for fear of falling for a Type 4 masquerading as a Type 1).
The upshot of all of this is that we should stop talking about transcendent moral facts or purposes, and encourage others to stop talking about them, too.
Just get on with the good works, all of you.