I’m just going to go through each section and briefly summarize the interesting arguments and offer potential responses on behalf of Tooley.
0. Plantinga’s Warm-Up Exercises
Plantinga warms up by noting that that even if Tooley’s conclusion that God’s existence is improbable given the evil in the world is true, the conclusion would not be enough to show that belief in God is unjustified (or in some other way epistemically bad) because the fact that there is evil in the world is a small subset of our total evidence. This is a point he returns to in the third section.
In this section, Plantinga spends some time presenting problems with Tooley’s evidential probability account of justification. He has two main criticisms. The first is that Tooley’s account of justification is circular. His second criticism is that it entails that all necessary truths are maximally (and equally justified). Let’s briefly look at those arguments.
The Circularity Charge
According to Tooley, epistemic justification for a proposition is a function of the evidential probability of that proposition. Plantinga seizes on Tooley’s candidate definition of evidential probability as – logical probability relative to one’s evidence.
Plantinga then pins an account of evidence on Tooley – Evidence must be whatever propositions one is justified in believing. And now we’ve got an account of justification that’s circular.
On Behalf of Tooley
Tooley could resist the claim that one’s evidence is whatever one is justified in believing. That seems like an odd characterization of evidence. Seeming states and perceptual experiences are often counted as evidence and those are not propositions that one is justified in believing. These things are not propositions that one could be justified in believing. Many would hold that they have propositional content. What’s odd is that Plantinga seems to countenance seemings states as evidence in section III (p. 175). (Of course, Tooley may have difficulties working this broader account of evidence into an account of evidential probability.)
The Every Necessary Truth is Equally Justified Objection
The more serious worry that Plantinga raises for Tooley’s account of justification is that it entails that all necessary truths are maximally (and equally) justified for a person. The idea is roughly that all necessary truths end up having a logical probability of 1 and so the evidential probability of any necessary proposition turns out to be 1 – and so all necessary truths are maximally (and equally) justified for me. But they’re not. So, Tooley’s account of justification is false.
I’ll set this one aside and let the probability hounds sniff it out.
Plantinga then retreats a little and notes that perhaps we can get by with an intuitive account of justification and proceed. Let’s turn our attention to Plantinga’s criticism of Tooley’s main arguments…
II. Tooley’s Arguments
In this section, Plantinga picks on Tooley’s argument for the conclusion that atheism is the default position, as well as Tooley’s main argument for the conclusion that God’s existence is improbable given the evil that exists.
Tooley’s Atheism is The Default Position Argument
Here’s a candidate way to extract Tooley’s Argument that atheism is the default position.
(1)There are, at least, two propositions such that
(i) those propositions are incompatible with the proposition that God exists, and
(ii) those propositions have the same instrinsic probability at the proposition that God exists.
(2) If 1, then the instrinsic probability that God exists is 1/3 (or lower).
(3) Therefore, the instrinsic probability that God exists is 1/3 or lower.
(4) If the Intrinsic probability that God exists is 1/3 or lower, then atheism (not theism or agnosticism) is the rational position given no other evidence propositional or otherwise.
(5) Therefore, atheism (not theism or agnosticism) is the rational position (given no other evidence propositional or otherwise.
Plantinga’s first response: Reject premise (4)
The mere fact that the intrinsic probability is 1/3 or less is insufficient for disbelief to be the rational position. Surely, says Plantinga, the instrinsic probability that there is life on Alpha Centauri is less than 1/3. And surely, says Plantinga, we shouldn’t believe that there isn’t life there. We should suspend judgement.
Plantinga’s second response: Reject (1)
(1) relies on the assumption that God (if God exists) is not a necessary being. For if God were a necessary being, then the instrinsic probability that God exists would be 1. (and we’re back to a similar point with Plantinga’s second criticism of Tooley’s theory of justification)
Tooley’s argument for the improbability that God exists given Evil
I’ll skip the summary of this argument. That’s what last week was for. Plantinga goes after premise (15) and (16).
Plantinga’s Criticism of Premise (15).
Tooley anticipates the idea that someone who thinks they have a theodicy would reject (15). Plantinga goes on to give a long list of other people who might reject (15), including theists who believe in fact that God has a good reason for permitting such a state of affairs, even if we don’t know what that good reason is. It will be rejected by many who justifiably believe in God and that God is perfectly good, who then infer from those two propositions that (15) is false.
Plantinga deflects the begging the question charge against him by noting that he is not offering an argument against (15). He is merely generating a list of people who might justifiably reject (15). Then he points out that it is Tooley who is actually begging the question. It seems that the point of Plantinga’s list is to attempt to show that Premise (15) must presuppose that belief in God is not justified.
On behalf of Tooley.
Plantinga says that (15) presupposes that people are not justified in believing in God’s existence. No it doesn’t. At least, you couldn’t read it off the premise. Whether premise (15) begs the question and presupposes that God exists depends on what the evidential basis for (15) is. If the evidential basis were, say, a strong irresistable seeming that (15) is true, then no presupposition would be made about the epistemic status regarding the proposition that God exists. (This way out for Tooley seems very similar to an atheological option that Plantinga discusses in the last section).
Plantinga rejects 16 for much the same reason that Trent did in his previous post – the short version – the probabilities here are inscrutable. I refer readers to that discussion.
III. The Justification of Theistic Belief
Plantinga notes again in this section that the probability of some proposition P can be relatively low given some other proposition, say Q, that you justifiably believe, but you could still justifiably believe P.
Example: The probability that you are dealt four aces, is incredibly low given that the are only 4 aces in a deck of 52 cards – but once you see the four aces, your perceptual evidence, swamps that low probability and you’re justified in believing that you have four aces.
If there were some faculty of sense-like perception of God, a sensus-divinitatus, then theists may well be in a position like a card player. Even if the probability that God exists is low given evil, a strong seeming fed to you by your sensus-divinatus could swamp it.
Plantinga then pushes Tooley into the Warranted Christian Belief corner and claims that the issue of whether or not Tooley’s argument shows that belief in God is unjustified hinges on whether or not there is a sensus divinatus. Whether or not there is a sensus divinatus depends on whether or not theism is true. If there is a God, it’s likely that there is one. If there isn’t a God, it’s likely that there isn’t one. So…whether or not Tooley’s probabilistic evil argument makes it irrational to believe in God depends on whether or not God exists.
IV. Is Evil a Defeater for Belief in God?
In this section, Plantinga retreats from the claim that theistic belief is justified, if God exists to the claim that it is prima facie justified absent defeaters (if God exists). He thinks he has sufficiently established the best arguments from the existence of evil to the non-existence of God don’t succeed, but then he considers what he thinks is the “strongest version of atheological appeals to evil”
One might hold that a person attuned to the evils of the world might have a non-inferentially justified defeater for the existence of God – a kind of inverse to the sensus divinitatus.
Plantinga’s response is roughly that perhaps for some people with a certain belief structure the proposition that there is evil will count as a defeater, but perhaps for others it won’t.
I’m not sure who this is a victory for, if anyone. It seems to concede to Tooley that a wide range of people might not be justified in believing in God on the basis of their apprehension of the presence of evil. On the other hand, it does attempt to preserve the rationality of theism for strongly committed theists.
Am I right in thinking this: According to Plantinga, if you’re on the fence and not firmly committed to the existence of God, then a person particular attuned to the evils of this world of the sort discussed in this section would not be rational in believing in God?
I’ll stop there. I’m sure people have other responses on behalf of Tooley, and I’d love to hear them.