I have been reading a paper by Peter van Inwagen, called “The problem of evil, the problem of air, and the problem of silence”. It is published in Philosophical Perspectives 5: 135-165 (1991) and you can find a copy at the following site, which gives a useful collection of van Inwagen’s papers:


Peter van Inwagen wrote the paper in response to Paul Draper, Pain and Pleasure: An Evidential Problem for Theists, Nous 23, 331-50 (1989). It considers the argument that the nature of the world, with all its pain and suffering, indicates that the source of the world is indifferent to it, or, at least, that this is more likely than that such a source cares about the world.

I will present the gist of the argument, as van Inwagen presents it, and summarise his reply.

First, let ‘S’ stand for suffering. van Inwagen gives this definition:

“Let ‘S’ stand for a proposition that describes in some detail the amount, kinds, and distribution of suffering—the suffering not only of human beings, but of all the sentient terrestrial creatures that there are or ever have been. (We assume the content of S is about what one would expect, given our own experience, the newspapers, history books, textbooks of natural history and paleontology, and so on. For example, … we assume that Descartes was wrong and cats really do feel pain.)”

He also uses the following two further definitions:

Let “theism” be the proposition that the universe was created by an omniscient, omnipotent and morally perfect being (one that has furthermore not ceased to exist and has never ceased to have those qualities).

Let ‘HI’ be ‘the hypothesis of indifference’, as follows:

“Neither the nature nor the condition of sentient beings on earth is the result of benevolent or malevolent actions performed by non-human persons.”

Now I will quote directly from van Inwagen again, with some remarks from me in square brackets. He first presents in his own words the argument which one can find in various places, and then he shows it to be much less convincing than it is widely supposed to be. He begins

“Even if we assume the probability of S on HI is high (that the denial of S is very surprising on HI), this assumption gives us no reason to prefer HI to theism.”

The phrase “the probability of X on Y” is a shorthand for “the probability that X is the case, on the assumption that Y is the case”. And it is indeed true that the probability of S on HI is high. So this gives encouragement to the atheist. But what about the probability of S on theism? We don’t know. So overall this seems to suggest we have here a reason to prefer HI to theism. But is this correct or only an appearance? Van Inwagen puts it this way:

“If there were such a reason, it could be presented as an argument:

[Argument 1]

The probability of S on HI is high

We do not know what to say about the probability of S on theism.

HI and theism are inconsistent.

Therefore, for anyone in our epistemic situation [that is, anyone possessing the evidence we have], the truth of S constitutes a prima facie case for preferring HI to theism.”

[A prima facie case is one that appears correct at first sight, or from the most immediate appearance, such that if one wants to deny it, one must bring in other considerations: the burden of proof lies with the one denying the case.]

This argument is the one that many atheists feel is quite strong (I previously commented on an example here). However, on consideration, one can show it is far from strong because one can provide arguments with the same structure but which people do not generally consider to be worth much at all. As van Inwagen puts it,

“This argument is far from compelling. If there is any doubt about this, it can be dispelled by considering a parallel argument. Let L be the proposition that intelligent life exists, and G be the proposition that God wants intelligent life to exist. We argue as follows:

[Argument 2]

The probability of L on G is high.

We do not know what to say about the probability of L on atheism.

G and atheism are inconsistent.

Therefore, for anyone in our epistemic situation, the truth of L constitutes a prima facie case for preferring G to atheism.

The premises of this argument are true. … But I should be very surprised to learn of someone who believed that the premises of the argument entailed its conclusion.”

This concludes the refutation of Argument 1, but more discussion is needed to show this more fully and to understand what is really going on when people advocate Argument 1.

Van Inwagen presents two more arguments with the same sort of structure as Arguments 1 and 2. Here is one of them.

Let S stand for silence, where we have in mind the absence of signs of intelligent life elsewhere in the galaxy. Let HI stand for the hypothesis of isolation, which is the hypothesis that humanity is the only intelligent species in the Milky Way galaxy. Let G (short for “little green men”) be the thesis that there is intelligent life elsewhere in the Milky Way. So we have that HI and G are inconsistent, and that the probability of S on HI is high (it is in fact 1). One can also argue that no human currently knows how to assess the probability of S on G. So we can construct Argument 3, which is worded precisely the same as Argument 1, but with these new definitions of the symbols S and HI, and with “theism” replaced by G. The purpose of this construction is to invite us to ask ourselves to what extent we feel such an argument suffices to show that no rational human should currently accept G (the thesis that there is intelligent life elsewhere in the Milky Way). Most of us feel that it does not amount to a knock-down case. We don’t think the people looking for signs of extra-terrestrial intelligence are all irrational.

So, to conclude, the idea goes as follows. It is claimed that the suffering of the world gives a prima facie case for the hypothesis of indifference (that the source of the world does not care about the world). One may refute this by the method of reductio ad absurdum, that is, by showing that a false, untenable result follows from the acceptance of the argument. For, if the argument (called “Argument 1” above) were valid, then other arguments with the same structure would also be valid. Examples are Argument 2 and Argument 3 above. But each of Arguments 2 and 3 is invalid (its premises are true, but its conclusion does not follow from them). It follows that Argument 1 is invalid also.

I feel that many people will find this refutation unconvincing, because in the case of the origin of the world, HI (indifference) can be argued to be a simpler or more likely hypothesis than the alternative (concern and intention), so, one might propose, Argument 1 does not have sufficient similarity to Arguments 2 and 3 to warrant the comparison. However, one should be careful not to allow vague impressions to cloud ones judgement when assessing rational arguments. In all these cases the logical structure of the given argument is unsound. Therefore each argument, as an argument, cannot be accepted. The reason why many people nevertheless feel that Argument 1 has more merit than the others must be because of other considerations.

The heart of van Inwagen’s paper is to show that the apparent force of Argument 1 is genuinely a false impression, and he does this in two steps, only one of which I have presented so far. The other step is primarily about epistemic humility. That is, it is about being less quick to assume that we know what we are talking about, or that we can make reliable value judgements, about things as cosmic as the very nature of the physical world. I will present this part in a subsequent post which can be found here.

It should be added that the suffering of the world remains a difficulty for theism. Of course it does, and no one is denying that. What we deny is that there is a valid argument from the condition of the world to the absence of concern in the origins or source or sustainer of the world, whatever that may be. Or at least, no such valid argument has been put forward so far. The world may be as it is and also very much cared about and worked with and through. We think that God’s working with the world is going on all the time, with a view to reducing suffering and making meaningful what suffering is not avoided, but this does not take the form of miracles by and large. It mostly takes other forms, such as inspiration. So, rather than having knock-down arguments one way or the other, we are left with a situation whose overall moral evaluation is beyond us, and with the task of alleviating suffering.


(5α,6α)-7,8-didehydro-4,5-epoxy-17-methylmorphinan-3,6-diol (Morphine) [Image: wikimedia commons]

[Part 2 of this discussion]