In attempting to use the problem of evil as an argument against theism, you’ll recall, Mackie agreed that he has no basis for saying that evil actually exists. Rather, he’s (purportedly) pointing out a logical contradiction between the theists’ position. We believe that evil exists (in some form or another), and he means to show that this contradicts our belief in a good God.
And this is important to keep in mind, because Mackie frequently argues by requesting evidence for the theist’s position. Thus, he seems to be shifting his goal posts as the momentary need arises.
Similarly, he argues from his own inability to picture reasons why a claim might be true. He answers the claim that freedom, in the end, brings about more good than bad with “whatever the valuable, other, aspects or consequences of freedom may be, it is at least logically possible that they should exist without such variation, that is, without bad choices actually being made”.
This section is peppered with this kind of thinking, and it is (whether he realizes it or not) an abandonment of his argument. Simply saying that something is possible does not mean that the theist has contradicted herself.
There are answers that could be given (such as the idea that our having knowledge that our choices are of moral significance is deeply important to God). But the point isn’t whether the theist can show that these are, at the end of the day, good answers. To show a true logical contradiction, Mackie needs to show that they can’t possibly be correct.
He also thinks that the theist needs to prove that we need libertarian free will to make real choices. Some people (the compatiblists) are convinced that one can be said to have free will, even though one’s decisions are completely determined by one’s brain chemistry and the corresponding laws of science.
Most people don’t see that as free will at all. Mackie is allowed to disagree if he’d like, but he is not allowed, in “pointing out a contradiction within theism” to insist that the theist needs to offer evidence that compatibilism is wrong. Yet he does exactly that.
To be fair to Mackie, he does, after a couple of pages on this, admit that this argument is fallacious. But this leaves one wondering why he included these pages at all. Certainly, it serves no purpose but (whether intentionally or not) to act as a rhetorical flourish, leaving the reader feel that theism has other problems that aren’t being answered by the free will defense.
Of course, theists have answered those problems elsewhere, but Mackie includes no two-page digression on those answers.
Instead, he offers an incorrect view of what theists mean by free will.
I don’t think this is intentional, but it is a problem nonetheless. Mackie seems unable to envision any description of human choice other than determinism and randomness (a la Copenhagen quantum mechanics).
He goes on to say that none of these help the believer in libertarian free will. Indeed, they do not for the very simple reason that he has left the actual position of libertarian free will off his list of possibilities.
Essentially, he’s still thinking like a materialist. He’s left out the possibility that the mind could be something other than the interaction of neurons (as materialists envision the interaction of neurons). Of course this leaves him with only these options, but this is precisely what the libertarian denies.
Mackie continues on for a few more pages, ostensibly trying to figure out what is meant by “free will”, but arguing at every turn that such things need to be proved.
And this is, again, shifting goal posts. Mackie is claiming to have seen a logical contradiction in the theist’s position. He, therefore, needs to show us a contradiction, not merely request more proof of the sub-points within that position.
At this point Mackie returns to the main argument “confident that it is not logically impossible that men should be such that they always freely choose the good”. But this, itself, a misstatement of the argument. It was never about logical impossibility, but about the logical fit to the goals of God.
Nor do I see anywhere that Mackie has actually given a reason for the confidence anyway. What he has done is insist that the theist prove that his position is impossible–and completely misunderstood the arguments given.
But, Mackie isn’t quite finished; he then moves to Plantinga’s (well-known) version of the argument. I’ll discuss that in a later post.