Saturday, April 30, 2016

Does God have no choice over natural evil?

On one view God allows various natural evils because they serve a useful purpose for the natural world. For example, what about tsunamis that kill people? Well this website says this (after talking about some earth science):

When earthquakes occur under the oceans, the plate's movement dissipates its energy through the ocean in the form of waves known as tsunami. When these waves make landfall, they can be up to 100 feet high and travel inland for several miles. The 2004 tsunami in the Indian Ocean caused widespread devastation to surrounding coastal areas, while killing over 200,000 people. A very large tsunami struck Japan, following a massive earthquake in 2011. We have already discussed the problems involved with stopping earthquakes and have determined that stopping them would result in a greater evil (lack of continental land masses and excessive solar radiation on the surface of the earth).

I’ll save my rebuttal for later, but first I’ll give a few other examples. Atheist philosopher William Rowe gave the example of a deer suffering a slow and painful death in a forest fire as a natural evil he argued that a good God would not allow.

Surely, a good God would want to prevent the suffering caused by fires.

As you learned in your elementary science classes (or Boy Scouts), fire requires three things—fuel, heat and oxygen. In most cases, the fuel is plant material. Obviously, God cannot eliminate plants, since all life is dependent upon the food and sequestered energy produced through photosynthesis.

Eliminating heat is problematic....One cannot eliminate oxygen from the environment

You get the idea. What about pain and suffering? From the website:

Atheist tend to assume that all pain, suffering, and death are bad or evil. However, physical pain is absolutely vital to our survival and well-being. If we felt no pain, we would do things to ourselves that could be very destructive.

One large problem with this is that God creating a universe of sentient creatures not susceptible to such pain and suffering seems to be within the realm of omnipotence. Why not create a world in which people are as invulnerable as Superman with there being no kryptonite? Moreover, what about heaven? Will people suffer horribly there because God can’t think of a way to do it better?

Thursday, March 31, 2016

Eyewitness Testimony and Miracles

I mentioned in my review of the William Lane Craig vs. Alex Rosenberg debate that the “eyewitness testimony is unreliable” objection is a bad one to use against e.g. arguments for the resurrection of Jesus. Here’s a somewhat obvious problem if eyewitness testimony is unreliable to the point where anything relying on eyewitness testimony should not be accepted as true: if you follow that rule consistently, then pretty much every fact of ancient history is tossed in the rubbish bin.

At the very least the “eyewitness testimony is unreliable” objection needs to be fine-tuned more; preferably there should be some explanation for why we shouldn’t trust eyewitness testimony in the case of miracles even though eyewitness testimony is often reliable in many other cases (remember, pretty much every scientific fact we have relies on eyewitnesses who recorded e.g. results of experiments; think of that next time you read a physics textbook). That’s what I’ll do in this article.

Happily, there’s an XKCD comic to help illustrate the idea. Behold:

In this case the neutrino detector serves as a representation for a generally reliable eyewitness (it’s accurate about 97.2% of the time), and the sun explosion represents a fantastical event with an extremely low prior probability. Don’t know what a prior probability is? Here’s one version of Bayes’ theorem:

P(H|E) =  P(H) × P(E|H)

In this case, P(H) represents the prior probability. Let’s use the following symbolization key:

  • H = The sun exploded
  • ¬H = The sun did not explode.
  • E = The neutrino detector reports the sun has exploded.

Suppose there’s a one in a million shot that the sun exploded (I’m pretty sure that’s an overestimate, but this will suffice for our purposes).

P(H) =  1

The probability that our neutron detector is telling us a falsehood is 1 in 36. So on average, of the times that the sun does not explode, it will inaccurately report it 1/36 of the time. Thus:

P(E&¬H) =  1  ×  999,999  ≈ 0.027778

Of the times that the sun does explode, it correctly reports it 35/36.

P(E&H) =  35  ×  1  ≈ 0.00000097222

Note that since the sun not exploding is a far more likely event, the frequency of false positives (≈ 2.778% of the time) vastly outweighs the frequency of true positives (≈ 0.000097222% of the time) given that the neutrino detector reports the truth only 35/36 of the time. According to the law of total probability:

P(E) = P(E&H) + P(E&¬H) ≈ 0.027778

Also, given the following equation and plugging in the values above for P(E&H) and P(H):

P(E|H) =   P(E&H)  ≈ 0.97222

Plugging in our values for Bayes’ theorem gives us this:

P(H|E) =  P(H) × P(E|H)  ≈ 0.000035

In the XKCD comic, the “Frequentist Statistician” committed what’s called the base rate fallacy, concluding that the sun probably exploded because the “base rate” reliability of the neutrino detector seems (to this statistician) to suggest the sun probably exploded. The problem, as I suggested before, is that on average the frequency of false positives vastly outweighs the frequency of true positives. This sort of effect is known as the paradox of the false positive, a.k.a. the false positive paradox. Very roughly, this paradox is where false positives are more likely than true positives when the overall high reliability of the “test” (most of the times the test results accurately report the situation) might lead one to believe that a positive result (e.g. the detector saying the sun exploded) means that a positive case is likely true.

What’s our application to eyewitness testimony and miracles? Miracles have extremely low prior probabilities, and as the case of the XKCD comic illustrates, with a low enough prior probability a fairly reliable information source could lead to false positives being more likely than true positives. This sort of thing is why we can rationally reject crazy alleged eyewitness reports like being abducted by aliens. It is also why we can be skeptical of alleged eyewitness testimony of miracles.

Monday, February 29, 2016

Murray and William Lane Craig on Animal Suffering

I once saw this YouTube video a while back titled, “Can animals suffer? Debunking William Lane Craig and other philosophers who say no.”

This is in response to William Lane Craig’s (and Michael Murray’s) bad argument attempting to mitigate the problem of evil with respect to animal suffering. The problem is, it doesn’t quite get Craig’s argument right. Neither William Lane Craig nor Michael Murry claim that animals don’t suffer; they say that animals don’t suffer as human beings do. The YouTuber wastes most of her time arguing that animals suffer or can’t feel pain, which was never quite really the issue. (They sometimes address the self-awareness aspect, but even then the people in there don’t always seem to correctly understand the claim.)

William Lane Craig speaks of these three levels of pain:

Level 3: Awareness that one is oneself in pain
Level 2: Mental states of pain
Level 1: Aversive reaction to noxious stimuli

Organisms which are not sentient, that is, have no mental life, display at most Level 1 reactions. Insects, worms, and other invertebrates react to noxious stimuli but lack the neurological capacity to feel pain.
Level 2 awareness arrives on the scene with the vertebrates. Their nervous systems are sufficiently developed to have associated with certain brain states mental states of pain. So when we see an animal like a dog, cat, or horse thrashing about or screaming when injured, it is irresistible to ascribe to them second order mental states of pain. It is this experience of animal pain that forms the basis of the objection to God’s goodness from animal suffering. But notice that an experience of Level 2 pain awareness does not imply a Level 3 awareness. Indeed, the biological evidence indicates that very few animals have an awareness that they are themselves in pain.

Best I can tell, by “Level 3” pain William Lane Craig is talking about the sort of pain that requires (among other things) being self-aware. It has been argued that while many brain-having species are sentient (capable of perceiving, having consciousness) relatively few are self-aware.

Suppose it’s true though that animals don’t have this “Level 3” plan. There’s still a big problem: Namely, by Craig’s own admission, the animals still suffer! A dog or cat might not have the self-awareness while suffering, but so what? As anyone who witnessed a beloved pet mewling in pain knows, these animals really suffer! Noting they lack self-awareness thereby preventing them from suffering in the same way we do does very little to resolve the problem.

It’s worth mentioning that Murray does claim that in addition to having merely Level 2 pain, it might be that animals don’t have the “negative-feeling” aspect of pain. Quoting Murray:

Finally, even if non-primates have PFCs, the human PFC is completely different from every other type of organism. Indeed one recent survey of primate neuroanatomy describes the human PFC as “absolutely, obviously, and tremendously” different (Rilling, Trends in Cognitive Science, vol. 18, no.1 (January 2014)). If those differences (which are destroyed in a lobotomy) are what makes negative-feeling-pain possible, then perhaps animals do not have such pain.

But I don’t buy it; empirical observation of suffering pets strongly suggest that the negative-feeling-pain exists even if only at a Level 2 state.

While we’re here though, I’ll address the issue of whether certain animals have a “pre-frontal cortex” (PFC) and whether animals other than the higher primates have it. The YouTuber says yes, Murray and William Lane Craig say no. The confusion seems to come down to (at least in part) different definitions as to what the “pre-frontal cortex” is. Quoting Michael Murray:

Second, it is not obviously correct that animals outside of humans and higher primates have PFCs. As even the folks at skydivephil note, there have been different ways of demarcating the PFC over time. For those not familiar with neuroanatomy it is worth pointing out that identifying regions of the brain is not like opening up the abdomen and distinguishing the stomach and kidney and liver. Brain regions are contiguous with each other, and there are different criteria that can be used to discriminate between regions. In the early twentieth century, the PFC was demarcated by location and cell type. Humans and higher primates have a certain cell type (known as “granular”) that composes a specific cortical layer, and the PFC was identified with this layer. Some later anatomists discarded this criterion for demarcating the PFC, in part because it made it hard to find a PFC in non-higher-primates. Thus, later anatomists defined the PFC functionally as the projection zone from another part of the brain known as the thalamus.

So the part of the brain that Murray was calling the PFC isn’t necessarily the same part that the YouTuber was calling the PFC. Was it a good idea to use a different, older definition of PFC? I think not. For what it’s worth here’s one peer-reviewed article they cited that I was able to confirm; quoting from the abstract Do rats have a prefrontal cortex?:

The lateral MD-projection cortex of rats resembles portions of primate orbital cortex. If prefrontal cortex is construed broadly enough to include orbital and cingulate cortex, rats can be said to have prefrontal cortex. However, they evidently lack homologues of the dorsolateral prefrontal areas of primates. This assessment suggests that rats probably do not provide useful models of human dorsolateral frontal lobe function and dysfunction, although they might prove valuable for understanding other regions of frontal cortex.

So evidently it does get at least a little bit messy.

For those who want to see a debate between Phil Harper (of SkyDivePhil) and Michael Murray on this issue (I know I did) see this Unbelievable podcast. Who won? In my opinion it wasn’t Murray, but you make your own judgment.

Saturday, January 30, 2016

Evil Is Evidence for Atheism or Theism?

One variety of the argument from evil goes like this:

  1. If horrible evils exist, then God does not exist.
  2. Horrible evils do exist.
  3. Therefore, God does not exist.

How might one justify premise (1)? Where “If P, then Q” is symbolized as P → Q, it is a theorem that Pr(Q|P) ≤ Pr(P → Q), so “Given P, probably Q” entails a high probability for “If P, then Q.” The likelihood that God does not exist given that horrible evils exist is high, so (1) is true.

A theist might argue that evil proves the existence of God because in the absence of God, there would exist no moral dimension to certain states of affairs; the moral property “moral badness” would not be associated with any action because if God does not exist then objective moral values do not exist. The argument might go like this:

  1. If God does not exist, then horrible evils do not exist.
  2. Horrible evils do exist.
  3. Therefore, God exists.

Atheists are divided on the probability of morality existing on atheism; some think morality probably doesn’t exist if atheism is true and would agree with (4) while disagreeing with (5), whereas some atheists agree with (5) and reject (4).

For those atheists who believe that moral values probably don’t exist on atheism and agree with (4), is it possible that evil (if it exists) renders God’s existence unlikely, evil is unlikely on atheism, and yet atheism is probably true?


Let’s use the following symbolization key:
  • G = God exists
  • ¬G = God does not exist
  • E = Horrible evils exists
  • ¬E = horrible evils do not exist

Consider the logically possible probability distribution values:


So for example P(¬G & E) = 0.09 in the table above. An important math equation where P(A|B) is the probably of A given B:

P(A|B) =  P(A&B)

The following are true:

  1. P(¬G|E) = 98.9011%
  2. P(¬E|¬G) = 90%

So statement (7) implies that premise (1) is probably true, and statement (8) implies that premise (4) is true. So for the atheist that denies objective moral values, he can accept both (1) and (4) are likely true while also maintaining a high probability for ¬G (perhaps via the presumption of atheism) but would of course deny premise (5).

Moreover, statement (7) basically says “The likelihood that God does not exist given that horrible evils exist is high” and so the atheist can affirm that even while denying the existence of evil. Even if the atheist denies the existence of horrible evils, the theist surely believes horrible evils exist, and so a high probability for P(¬G|E) is problematic for the theist in a way that isn’t for the atheist.