After (basically) endorsing Hume’s argument against belief in miracles, J. L. Mackie turns to discussion of ontological arguments for God’s existence (arguments that try to argue for God’s existence based simply on reason and the idea of God).
He opens with a couple of arguments pressed by Descartes, and rejects them. And personally, I agree. Descartes claimed that God must exist because we could not have clearly perceived the idea of the infinitely powerful unless something infinitely powerful existed. I won’t get too far into this, because I’m in complete agreement with Mackie’s objection that we never really perceive something infinitely powerful. None of us can really imagine that, and this is, I think, devastating for Descartes’ argument.
As to Anselm’s much more famous ontological argument for God’s existence, things get much more interesting.
Most people (including myself, I must say) find the argument suspicious. To say that God is defined as the greatest possible being, then to say that existing would be greater than not (and, therefore, God exists) doesn’t sit well with me personally.
What is interesting is how we each go about rejecting the argument. Mackie denies that existing would make a thing greater than not existing, which is fine insofar as that goes, but he never gives a reason for this denial. He admits that it is a cogent thought that existence is what philosophers call a “great-making property”, but simply denies that this thought is true.
I’ve always felt that I have a good reason to question this premise. That is “greatness” assumes a standard of good and bad, against which we might measure the object in question. And, personally, I don’t see how we can have a standard by which we presume to measure God–much less worked it out well enough to know what it is–until we’ve already settled the question of God’s existence.
The trouble with this is that it leads us right into the moral argument for God’s existence. Anyone pressing this objection to Anselm has basically three options: 1) Defend nihilism, 2) Defend a secular case for objective values that can avoid this argument from greatness, or 3) Accept theism.
The third isn’t problem for me, of course, but those arguing against the conclusion of theism have two very difficult choices, and I worry that this is part of the reason why Mackie doesn’t offer his reason for rejecting the idea that existence is a great-making property.
To me (and even to Mackie), Anselm could retort that we can know that existence constitutes a great-making property even before understanding the ultimate source of greatness. That would be harder to refute, and I’m not concerned to do so here.
I do find this argument suspicious, but less so than Mackie’s dismissal without offering a standard by which he does so. If he can’t offer a clear alternative of what constitutes greatness (even if that is nihilism), then he can’t claim to have done away with theism.
And that is a major issue that continues to come up (and will continue to come up later in the book). It isn’t enough to simply cast doubt on a proof. One must offer a basis on which one believes the premises that support the counter argument (that is, an alternative view). But this is something that atheists, in my experience, notoriously avoid doing.
From here, Mackie turns to Plantinga’s ontological argument. We’ll discuss that next.
Fide Dubitandum 
November 15th, 2013 at 4:20 am
I wanted to comment regarding a point of correction in your post and offer references to criticisms of Saint Anselm’s argument for you to consider. I am purposely attempting to keep my thoughts out of my response and linking to text for you to read. (Added more regarding Descartes argument as well.)
Saint Anselm of Canterbury, a Doctor of the Catholic Church, has his name misspelled in your post. I understand mistakes are unintentional and I would, and do, appreciate when my own mistakes are corrected.
Saint Anselm’s argument proceeds as so;
a) That than which nothing greater can be thought cannot be thought not to exist.
b) God is that than which nothing greater can be thought.
c) God cannot be thought not to exist.
I understand the middle premise (b) in Saint Anselm’s argument is born from Saint Augustine’s “De Doctrina Christiana” where in Ch.7 Saint Augustine is arguing on “What All Men Understand by the Term God” and in that our understanding of God excels over all other knowable things.
– De Doctrina Christiana: Ch.7 [link]
Saint Thomas Aquinas directly critiqued the above ontological argument from Saint Anselm’s “Proslogion” in several of his works.
– In Primum Librum Sententiarum: Dist.3, q.1, a.2, 4 & ad 4 [link]
– In Boethii de Trinitate: q.1, a.3, 6 & ad 6 [link]
– Quaestiones Disputatae de Veritate: q.10, a.12, 2 & ad 2 [link]
– Summa Contra Gentiles I: 10 & 11 [link]
– Summa Theologiae Ia: q.2, a.1, 2 & ad 2 [link]
Additionally, here is an interesting summary of Descartes’ argument I ran across and have been considering (once again) for some time. I thought it would be worth sharing and have strenuously utilized copy/paste to do just that.
“…
1.) To exist as an idea is different from being real.
Descartes calls ideas things with objective existence (i.e. they exist as objects) as opposed to things with real existence, which are said to have formal existence.
2.) Things with objective existence are effects of something with formal existence.
The idea of a unicorn had to come after real horses, or from something else from which we got the idea of white, horse, and horn. In the words of the next premise, objective realities are less real than formal ones.
3.) Things with objective existence arrange themselves in layers of the more and less real.
“More and less real” means this: A is more real than B if the actuality of A is presupposed to the possibility of B. And so on this account, accidents are less real than substances, finite changeable substances are less real than the matter, energy, and physical laws that existed before them, and a Creator is more real than matter, energy, and physical laws.
4.) Causes have at least as much reality as their effects.
True by definition of “more and less real” given above.
Conclusion: The objective existence of my idea of God is caused by God’s actual existence.
While one can explain the objective being of something as merely objective by pointing to any old formal reality, and in this sense we could explain God by positing the humblest formal reality, nevertheless this would not suffice to explain the idea precisely of God, which exists at the highest possible layer of being and therefore is proportionate to some formal reality at that level. We could not have come up with an idea of centaurs from merely considering the various accidents that a centaur might possibly have. One needed more than just “orange” and “two-meters high” to come up with such an idea – we needed experience of various substances and animals. Thus to explain the idea of God as such there must be some formal reality at the divine level of existence, which is, by definition, God.
…”
November 15th, 2013 at 9:58 pm
I’ll have to think on this. I appreciate the summaries (and I appreciate the spelling correction–that is not my strong suit).
As to the arguments, I keep going around with regard to Anselm’s argument. I react negatively to first premise. I don’t have a definitive argument, but am merely suspicious. I mostly am left acknowledging that I need to read more on the argument.
Getting there, albeit slowly.
As to Descartes, what you’ve copied here is much more reasonable than the summaries I’ve read (both in Mackie and elsewhere). I can see why some would find this more persuasive. Still, I don’t think that he’s established that the idea of the divine could not be caused by a mundane experience.
But that’s simply my position as I delve into these ideas.
In any case, I very much appreciate the information and explanation. I’ll have another look at the arguments with this in mind.
November 17th, 2013 at 3:08 pm
I would believe you, at the time of writing your comment, had not read through the links I posted. I direct you to read the Saint Thomas Aquinas links and maybe you will find an argument supporting your suspicions of Saint Anselm’s first premise.
I do not understand why the qualification is necessary. Please, am I misunderstanding your comment or reasoning.
November 17th, 2013 at 5:51 pm
That is indeed true. I’m looking over them, but slowly.
I’m definitely open on this one; I simply don’t know.
As to the comment about Descartes, my question is about premise 4. I agree with it as an isolated statement, but am not convinced that it can be applied to ideas in a way that will make his argument successful.
The basic objection is this:
Yes, causes have at least as much reality as their effects, but the idea of the infinite does not, itself, have infinite reality. It has a finite reality, and would, therefore, require only a finite cause.
I’ve marked the links you’ve provided, and will read through them, but if you happen to know of a good discussion of that objection, I’d be interested.
Hopefully, that was more clear.
(If not, apologies.)
November 17th, 2013 at 8:58 pm
This is an axiom and if you do not accept this the discussion needs to go back to a prior step. That is ok. Just a point which need to be address before dealing with Descartes argument.
November 17th, 2013 at 10:15 pm
I agree with that axiom. What I don’t yet understand is what appears to be an additional necessary axiom:
5. The idea of the infinite has infinite reality.
I don’t yet see how this has been supported, nor do I see how the argument can succeed without such an axiom (or one like it). Personally, I’d be very excited to be shown to be wrong on that point–but haven’t yet encountered a good defense of it (or of the idea that the argument doesn’t require this premise).
November 18th, 2013 at 2:57 pm
I am puzzled why you feel the need for an additional axiom (5) and one that equates the cause and effects reality.
First, I am not sure your claim to accept axiom (4) is accurate as you do not agree to its universality. Again, this is fine and discussion on this should go back to arguments on the validity of such a premise.
Second, I see axiom (4) statements to support a cause being greater than or equal to its effects, but not concluding a required necessity of the equality of a cause and its effects. Do you have a reason why you think the idea of the infinite requires infinite reality?
November 20th, 2013 at 3:07 pm
I do think I accept the universality of premise (4). But, reading over my past statements, it does seem that I was claiming otherwise. That being the case, apologies. I do think it applies to the idea of the infinite.
Rather, my objection was this:
Given that the idea of the infinite requires a cause which has equal or greater reality than it, we still cannot rule out finite causes, because that idea is itself of finite reality (even though it is directed toward infinite reality).
It seems likely that this idea is simply an extrapolation from “beyond what I can know or imagine” to “beyond all boundaries”.
That is why I believe that his argument would need something like premise (5) in order to succeed. But, obviously, if it could be shown that humans could not have made the extrapolation mentioned above, that would serve as well.
Okay, I hope that is more clear.
If so, I’m definitely open to the idea that answers have been given to this objection. I’d be very interested in reading about them.
But, otherwise, best to you.