The third moral argument Mackie discusses is interesting in that it was put forward by a man (Sidgwick) who did not himself accept it (but just thought it was interesting). Personally, I find this singularly unfortunate in that it is a good argument, and might have been better known and better defended had it been advanced by someone who actually believed in it.
The argument could be summarized as follows:
1. What one has the most reason to do is what will best secure one’s long term happiness.
2. What one has most reason to do is what morality requires
3. If there is no moral government to the universe, what will best secure one’s happiness won’t always be what morality requires.
If one accepts all three of these statements, if follows that there is a “moral government” to the universe–which would mean that materialism is false, and that theism is likely to be true. Mackie rejects this argument, I think, far too easily. He seems to accept all three premises–at least, he never challenges any of them. And he agrees that the conclusion follows from the premises. Still, he insists that the conclusion is wrong.
First, he does this by dismissing the idea that he should accept a view on the grounds that not accepting it would be to reject rationality. He accepts that this makes his view of ethics irrational, but seems strangely unbothered by this. This leaves one wondering why one couldn’t, equally, have a view of God that he considers irrational. He never addresses this point.
And I think it is significant, in that it has become so common. Many people who are completely open about the fact that their view of morality is irrational can be found loudly mocking, ridiculing and otherwise acting scandalized toward religious believers for “believing irrational things”.
Of course, I don’t accept that belief in God is irrational, but I really can’t see why such people should have a problem even if it were.
Second, he claims that “facts should inform our beliefs, not the other way around”. But, if the argument is sound (which he seems to concede that it is), then there are moral facts which should inform his beliefs about God. He’s simply begging the question if he wants to say that morals aren’t facts.
Third, he offers some examples that, he thinks, reduces the argument to absurdity. He claims, for instance, that one could use the idea that we shouldn’t retreat in battle, together with the idea that we shouldn’t let our army be destroyed, to mean that we will be victorious in every battle.
Clearly, this is silly, but I fail to see how this actually follows from the argument above. Is it really a moral imperative that an army not retreat under any conditions whatsoever? Or does morality simply dictate that one not retreat without sufficient reason to do so? I’d say it is the latter, but this option is simply ignored by Mackie.
And this is another common mistake. Relativists rarely seem to understand the difference between objective morals and absolute morals. They seem to think that anyone who believes in moral objectivity believes that no consideration whatsoever should be given to the situation one is in. But no moral objectivist I know has ever said such a thing. Of course moral principals will manifest differently in different situations–that was never what was in dispute.
Mackie also claims that what is moral must follow from (supervene on) what is factual. But, as Plantinga points out, this means precisely what Mackie says it does not mean: that morals can be clues to what is factual.
After all, a news report supervenes on real events. That is to say that, were it not for those events, there would be no report. But this doesn’t remotely mean that a news report is no reason to think the reported-on event didn’t happen. Rather, it is precisely because a report is based on an event that it is a useful source of information.
Thus, if morality is supervenient, then the same principle applies. Mackie can’t simply say that morals depend on the facts of the situation in order to say that they tell us nothing about the facts.
So, all this is simply beside the point. After all, Mackie is criticizing a logically valid argument, with premises that he accepts, on the grounds that it leads to a conclusion that his materialist atheism is false. If “facts should inform our beliefs, not the other way around”, then he should accept the conclusion of the argument.
As much as I respect Mackie, he seems to be in the grip of an ideology here–claiming that true premises and valid logic can lead to a false conclusion is a fairly blatant rejection of rationality.
As to the argument itself, I’d love to see some more development of this idea. There is definitely more that could be said, but, at the end of the day, it is clear that atheism and morality are logically incompatible with one another.