After addressing Aquinas’ Third Way (rather unsuccessfully, I’d say), Mackie turns his attention to the Kalam Cosmological Argument (for those very few who aren’t already familiar with it, I discuss it here). It is important to remember, however, that Mackie argued against Aquinas by suggesting that the world is past finite.
Those who know something about Aquinas’ arguments will know that this misses the point. But the more pertinent issue is that he opens his discussion of the Kalam by suggesting that the universe is infinitely old.
And it is my repeated contention that Mackie can’t appeal to contradictory ideas like this in order to “refute” arguments for God’s existence. He needs to present a view of how things are, and defend that view as more rational than theism.
But, if he avoids taking a stance here, he makes another claim I find easy to challenge.
That is, he claims that arguments against an infinitely old universe don’t work, because they don’t have an infinitely distant starting point. Rather, they have no starting point.
But anyone familiar with the arguments against an infinite past should see the problem with this. They aren’t arguments against a beginning point, specifically, being infinitely distant in the past, but against any point being infinitely distant. This objection does nothing to affect the argument.
In his third line of attack, Mackie points out that the same rules don’t apply in trans-finite arithmetic that apply in finite math. This is true, but completely misses the point. Rather the point is that, since the same rules don’t apply, the physical universe (which, as science has shown, is governed by the rules of finite math) can’t contain infinite numbers of things.
But, of course, most accept the idea that the universe had a beginning. The real controversy (odd as it seems to me) is over the idea that having a beginning means a thing has a cause.
Mackie simply claims that there is no reason to assume that things can’t come into existence without a cause. But I don’t think I exaggerate to say that I’d be thoroughly mocked for attempting to defend theism on grounds as flimsy as this. To seriously suggest that things can pop into existence for no reason at all as an alternative to theism strikes me as a fairly desperate approach.
He does make the more reasonable (but still poor) objection that God’s creation ex nihilo suffers from the same problem. Personally, I agree that this would be a serious objection–were it true. But, regardless of the phrase “ex nihilo”, it is not the claim that the universe has no cause. That is simply to misunderstand what theists have claimed, and attack a straw man.
He throws out other arguments, such as the idea that God cannot exist outside of time because “this would be a complete mystery” (as if our inability to picture a thing should stop the the quantum physicist from reaching a conclusion). But, in the end, he offers no reason to think either that the universe is eternal, or that past-finite things need causes. Nor does he counter the reasons given in support of these ideas.
This being the case, there remain two problems for Mackie:
1. That he’s just finished basing an argument on the idea that the universe is past-finite
2. That attacking the idea that things have causes contradicts the entire enterprise of rational inquiry, including science.