bookmark_borderAn F-Inductive Argument from Consciousness for Theism, Revisited

Edited on 15-Feb-20
While some theistic arguments are “God of the gaps” arguments, many, including those defended by Christian philosophers, are not “God of the gaps” arguments. Before accusing a theist of trotting out another “God-of-the-gaps” argument, atheists should first verify that the argument actually is a “God-of-the-gaps” argument.
Here is the basic structure of a “God-of-the-gaps” argument:

  1. Some odd or puzzling thing, E, occurs or exists.
  2. Science is unable to offer a plausible, God-free explanation for E.
  3. Therefore, God is the best explanation for E.
  4. Therefore, God exists.

There are many, well-known problems with such arguments. I’ve written on this topic elsewhere, so I won’t repeat those points here. Instead, I want to sketch how a theistic argument can avoid appealing to a gap in scientific knowledge. Here is the structure of an F-inductive argument from consciousness:
Let E=consciousness exists; N=naturalism; T=theism; B=background information; Pr(|H|)=the intrinsic probability of H; and Pr(x|y)=the epistemic probability of x conditional upon y

  1. E is known to be true, i.e., Pr(E) is close to 1.
  2. N is not intrinsically much more probable than T, i.e., Pr(|N|) is not much greater than Pr(|T|).
  3. Pr(E| T & B) > Pr(E | N & B).
  4. Therefore, other evidence held equal, N is probably false, i.e., Pr(T | B & E) > 0.5.

Whatever problems may exist with that argument, being a “God of the gaps” argument isn’t one of them. The present inability of science to explain consciousness plays no role whatsoever in the argument. What’s doing the work in the argument is the fact that theism, as a version of supernaturalism, entails that consciousness exists, whereas naturalism has no such entailment.
Allow me to explain. “Naturalism” is really just short-hand for “source physicalism,” which says that the physical world exists and, if the mental world exists, the physical explains why the mental exists (or, to allow for eliminative materialists, appears to exist). “Supernaturalism” is really just short-hand for “source idealism,” which says that a mental world exists and, if a physical world exists, the mental explains why the physical exists (or, to allow for eliminative idealists, appears to exist). “Theism” is a specific version of supernaturalism; it says that the mental being or entity which explains why the physical exists is a perfect supernatural person.
N.B. While theism does not entail human consciousness exists, theism does entail consciousness exists because theism entails that God exists and God is conscious, by definition. In contrast, naturalism is compatible with the non-existence of consciousness. So the existence of human consciousness, while not entailed by theism, isn’t surprising on theism in the way it is on naturalism. In that sense, human consciousness is evidence favoring theism over naturalism.
Objections to the Argument
Objection to (1): “We have no idea what ‘consciousness’, ‘mental,’ and ‘physical’ mean. Science can’t explain some E if the E is poorly defined.”
Reply: By a “mental world,” I mean the existence of a private, subjective world. By a “physical world,” I mean the existence of a public, objective world. By “consciousness,” I mean sentience.
Objection to (2): “But intrinsic probabilities don’t appeal to the propositions included in our background knowledge, and so ignore prior probabilities.”
Reply: As we say in computer science, that’s a feature, not a bug. Intrinsic probabilities come before prior probabilities. As the name implies, intrinsic probabilities are probabilities determined solely by the intrinsic properties of a proposition. Draper has argued (convincingly, in my opinion) that intrinsic probabilities are determined by scope, modesty, and nothing else. In contrast, prior probabilities are determined by the propositions in our background knowledge, such as “A physical universe exists,” “The universe is life-permitting,” “So much of the physical world is intelligible without appeal to supernatural agency,” and so forth.
Objection to (3): “The claim that Pr(E | T & B) > Pr(E | N & B) is unfounded because generic or mere theism doesn’t contain enough information to predict or demystify E. One would have to appeal to a specific kind of theism to justify something like (3), but a more specific kind of theism would have a lower intrinsic probability than mere theism.”
Reply: This is false for the reason explained above. While theism does not entail human consciousness exists, theism does entail consciousness exists because theism entails that God exists and God is conscious, by definition. In contrast, naturalism is compatible with the non-existence of consciousness. So the existence of human consciousness, while not entailed by theism, isn’t surprising on theism in the way it is on naturalism. In that sense, human consciousness is evidence favoring theism over naturalism.
Objection to (4): “But consciousness depends upon a physical brain. That’s more probable on naturalism than on theism.”
Reply: Correct. We know much more about the mental than the fact that it exists. We also know that it is dependent upon the brain, a fact which is much more likely on naturalism than on theism. So, once the evidence about consciousness is fully stated, it’s clear that there is also evidence favoring naturalism over theism. That fact, however, does nothing to refute this argument, which contains an “other evidence held equal” clause in its conclusion.
Objection to (4): “But the naturalistic evidence of mind-brain dependence outweighs the theistic evidence from consciousness.”
Reply: I am not aware of anyone having offered a successful argument for that claim. It’s not clear to me how such an argument could be adequately defended.
Objection to (4): “But the history of science contains numerous examples of naturalistic explanations replacing supernatural ones and no examples of supernatural explanations replacing naturalistic ones. That gives us reason to expect that science will eventually explain consciousness without God.”
Reply: I agree that gives us some reason to expect that science will eventually explain consciousness without appealing to God. That doesn’t change the fact, pointed out by (3), that the content of “naturalism,” as I have defined it, gives us no antecedent reason to expect consciousness to exist if naturalism is true, whereas “theism,” as I have defined it, does give us an antecedent reason to expect consciousness. This promissory naturalistic ‘atheodicy’ has no logical relevance to the argument anyway.
Objection to (4): “But (4) must be false because theism is false.”
Reply: That would follow only if one assumes that there can never be true evidence for a false proposition, but why assume that? There can be circumstantial evidence that a defendant is innocent of murder, while at the same time there could be other evidence for the defendant’s guilt, such as DNA evidence, which completely outweighs the circumstantial evidence. Similarly, a theist might say, “Suffering, imperfection, poor design, and mind-brain dependence are evidence against God’s existence, but that evidence is completely outweighed by the evidence from the finite age of the universe, the life-permitting conditions of the universe, human consciousness, etc.” Similarly, even if one believes (as I do) that it’s extremely improbable that God exists, one can consistently allow that consciousness is evidence–even strong evidence–favoring theism over naturalism, while simultaneously believing that other evidence outweighs the theistic evidence. People in general need to stop taking a binary, “all-or-nothing” approach to evidence.

bookmark_borderOpening Statement from My Debate with Frank Turek

Although I’ve recently been too busy to spend any time writing original content for this blog, I’ve decided to post my opening statement from my 2016 debate with Frank Turek. Enjoy!


Good evening! I’d like to thank Craig Freerksen for organizing this debate. I’d also like to thank Dr. Turek for agreeing to participate. Finally, I’d like to thank all veterans, including my opponent, for defending the right to have a debate like this. Now, speaking of our country, I thought I’d borrow a slogan from the presidential campaign. I’m not selling any hats, but I’m here to “make atheism great again.”


In this debate, we’ve been asked to assess what best explains reality: naturalism or theism? Before we can answer that question, we need to have some idea of what we’re talking about, so let me begin by defining some terms.
First, by “naturalism,” I mean the view that the physical exists and, if the mental exists, the physical explains why the mental exists.[1] If naturalism is true, then there are no purely mental beings which can exist apart from a physical body and so there is no God or any person or being much like God.
Second, by “supernaturalism,” I mean the view that the mental exists and, if the physical exists, the mental explains why anything physical exists.[2] If supernaturalism is true, then there is no purely physical matter which can exist without some sort of ultimate mental creator.
Third, “personal supernaturalism” is a type of supernaturalism; it adds on the claims that one or more personal mental entities exist and, if a physical world exists, it or they produced the physical world for a purpose.[3]
Fourth, “theism” is a type of personal supernaturalism; it adds on the claim that there is just one mental entity, God, who is all-powerful, all-knowing, and morally perfect.[4]
Finally, fifth, “otherism” is a catch-all category. It says that both naturalism and supernaturalism are false.[5]
Now the question before us in tonight’s debate is this. What best explains reality: theism or naturalism?
In support of a naturalistic answer to that question, I’m going to defend three basic contentions:
(1) The best explanation is the explanation with the overall greatest balance of intrinsic probability and accuracy;
(2) Naturalism is an intrinsically more probable explanation than theism; and
(3) Naturalism is a more accurate explanation than theism.

First Contention

Let’s look, then, at my first basic contention: the best explanation is the explanation with the overall greatest balance of intrinsic probability and accuracy.
By “intrinsic probability” of a hypothesis, I mean the probability independent of the evidence we have for or against it. The intrinsic probability of a hypothesis is determined entirely by its modesty and coherence.[6]
By “accuracy” of a hypothesis, I mean the degree to which a hypothesis’s predictions correspond to reality. We measure accuracy by looking at “evidence.”
By “evidence” I mean something which makes something else more probable than it would have been otherwise. Let me give you an example.[7] Imagine you have two jars of red and blue jellybeans. In the first jar, 90% of the jellybeans are blue and the rest are red. In the second jar, 90% of the jellybeans are red and the rest are blue.
Now imagine you are handed a jelly bean from one of the jars, but you don’t know which jar it came from. If it’s a blue bean, that’s evidence it came from the first jar, not the second. The blue bean doesn’t disprove that it came from the second jar because the second jar also has blue beans, but it’s more likely that it came from the first because there are more blue jellybeans in the first than in the second. Similarly, if it’s a red bean, that’s evidence it came from the second jar. The red bean doesn’t disprove that it came from from the first jar because the first jar also has red beans, but it’s more likely that it came from the second because it has many more red beans.
Mathematicians have a formula called Bayes’ Theorem, which can be used to specify the relationship between intrinsic probability, accuracy, and the overall or final probability of a hypothesis. It follows from Bayes’ Theorem that a hypothesis is probably true, just in case it has a greater overall balance of intrinsic probability and explanatory power than do its alternatives collectively.

Second Contention

Let’s look, then, at my second basic contention: naturalism is an intrinsically more probable explanation than theism.
Intrinsic probability is determined by modesty, coherence, and nothing else. By “modesty,” I mean a measure of how much the hypothesis asserts.[8] The more a hypothesis claims, the more ways there are for it to be false and so, before we start looking at evidence, the less likely it is to be true.
By “coherence,” I mean a measure of how well the parts of a hypothesis fit together.[9] If the different parts count against each other, the hypothesis is less coherent and less likely to be true.
Now consider naturalism and supernaturalism. They are symmetrical claims: naturalism claims that the physical explains the mental, while supernaturalism claims that the mental explains the physical. Both claims are equally modest and equally coherent. Before examining the evidence, both positions are equally likely to be true.[10]
With these definitions in mind, then, I can now defend my second contention. Theism is a type of supernaturalism but could be false even if supernaturalism is true. Furthermore, theism is less modest than either supernaturalism or naturalism. Therefore, before we look at evidence, it is less likely to be true than supernaturalism or naturalism.[11] But that entails that naturalism is intrinsically more probable than theism.

Third Contention

Finally, let’s move onto my third contention: naturalism is a more accurate explanation than theism for many facts.
I’d like to present seven lines of evidence that are red jellybeans, i.e., things more probable on naturalism than on theism.[12]

Physical Matter

(1) Naturalism is the best explanation for the fact that physical reality exists.[13]
If naturalism is true, then physical reality must exist. That’s just part of what naturalism means.
If theism is true, however, things look quite different. The existence of physical reality doesn’t disprove theism; if God exists, God could have created physical space, matter, and energy as part of a plan to create a universe for human beings. But God could have also chosen to create other minds without physical bodies, such as angels. Or God could have chosen to create nothing at all. In other words, God’s existence doesn’t require a physical reality.
So because the physical has to exist on naturalism but does not have to exist on theism, it follows that the existence of physical reality is evidence favoring naturalism over theism.

Success of Science

(2) Naturalism is the best explanation for the fact that science has been so successful without the supernatural.[14]
Imagine a library that contains textbooks for all of the sciences—such as physics, chemistry, and biology—and summarizes current scientific knowledge. The percentage of such knowledge which makes no appeal to the supernatural is extremely high.
Of course, one hears about specific scientific questions which (allegedly) do not have a plausible naturalistic explanation, such as cosmological fine-tuning, the origin of life, and consciousness. But, even if that is or were true, the history of science contains numerous examples of naturalistic explanations replacing supernatural ones and no examples of the reverse. Indeed, naturalistic explanations have been so successful that even most theists concede that supernatural explanations are, in general, unlikely to be true.
Such explanatory success is just what we would expect on naturalism–which entails that all supernatural explanations are false–than it is on theism.[15] And that’s my second line of evidence against theism.

Biological Evolution

(3) Naturalism is the best explanation for the fact that complex life  evolved from simple life.[16]
I’m going to list five scientific facts which support biological evolution. Since Dr. Turek likes acronyms, I’m going to give you the evidence in an acronym, BONES.

  • B is for biogeography;
  • O is for vestigial organs;
  • N is for natural selection;
  • E is for embryology; and
  • S is for stratified fossil record.

Let’s look very briefly at each of these.


First, the evidence indicates that the habitats of plants and animals are distributed in a puzzling way. For example, why are there no land-based mammals on any island more than 300 miles away from the mainland? As University of Chicago biologist Jerry Coyne puts it, “The biogeographic evidence for evolution is now so powerful that I have never seen a creationist book, article, or lecture that has tried to refute it.”[17]

Vestigial Organs

Secondly, a variety of animals have organs which display traits that would be unnecessary if the organs had been designed from scratch, but would have been useful to an ancestor.

Natural Selection

Thirdly, when the genetic differences between living things provides an advantage, things with that advantage tend to be more successful at survival and reproduction than things without that advantage. This is the essence of the process Darwin called natural selection.


Fourthly, as Coyne points out, the evidence indicates that all vertebrate embryos begin development in the same way, looking like embryonic fish, but as they progress, they often go through strange contortions before reaching their final form.[18]

Stratified Fossil Record

Fifthly, the available fossil evidence indicates that as one goes from the oldest to the youngest layers of the fossil record, the layers show gradual change from simple to more complex life forms.
Taken together, the BONES evidence is much more probable on biological evolution (which says that complex life evolved from simple life through trans-generational genetic change)[19] than it is on special creationism (which says that God created all life virtually simultaneously).[20]
If either naturalism or supernaturalism is true, life could exist or not exist. If naturalism is true and life exists, evolution pretty much has to be true. But if theism is true, God didn’t have to use evolution. Furthermore, since theism says that at least one mind existed before any physical matter, it gives a reason to expect that any other minds are fundamentally nonphysical. But that, in turn, leads us to predict conscious life was created independently of nonconscious life, contrary to what evolution claims.[21] So theism predicts that evolution is false.
Thus, the scientific fact of evolution is more likely on naturalism than on theism, and so that’s my third line of evidence against theism.

Pain and Pleasure

(4) Naturalism is the best explanation for the biological role (and moral randomness) of pain and pleasure.[22]
I’m going to give three lines of evidence.
First, moral agents experiencing biologically useful pain and pleasure.
Suppose you are a teenager sleeping in a hotel that has caught on fire. The hotel is old and doesn’t have smoke alarms. The fire gets closer and closer to you until you are actually in pain from the smoke and the intense heat. Your pain wakes you up in time for you to escape; you survive and start a family in your twenties. Your pain in this case was biologically useful because it contributed to your survival. This is just what we would expect on naturalism (and human beings are the products of evolution by natural selection).
Second, moral patients experiencing biologically useful pain and pleasure.
Most human beings are moral agents, people who can be held responsible for their actions and their consequences. But some human beings, such as young children and humans with certain mental disabilities, as well as non-human sentient animals, such as primates and dolphins, are moral patients: sentient beings who can be harmed from their own point of view, but are not responsible for their actions.
On naturalism, we would expect that (biological) sentient beings, including moral patients, would experience pain and pleasure because moral patients are biologically similar to moral agents. On theism, however, we would predict that moral patients do not suffer the same kind of pain as moral agents because such pain plays no known moral role in the lives of the moral patients who experience it.
Third, sentient beings experiencing gratuitous pain and pleasure.
Consider, for example, an animal trapped in a forest fire, suffering horrific pain as it slowly burned to death. On the one hand, this kind of pain is biologically appropriate: it is biologically useful that animals in general feel pain when they come in contact with fire. But, on the other hand, this specific instance of pain was not biologically useful because it did not contribute to the biological goals of survival or reproduction.
On naturalism, this is just what we would expect.  If naturalism is true, all animals are the byproducts of unguided evolution by natural selection, which is both indifferent to suffering and incapable of preventing it.
But if theism is true, God could “fine tune” animals so that they only experience physical pain and pleasure when it was morally necessary. So theism leads us to expect that pain and pleasure are fundamentally moral phenomena, which just happens to be connected to the biological goals of survival and reproduction. That’s a huge coincidence that naturalism doesn’t need.
So this evidence is very much more probable on naturalism than on theism.

Mind-Brain Dependence

(5) Naturalism is the best explanation for the fact that human minds are dependent upon the physical brain.[23]
Philosopher Paul Draper of Purdue University puts it this way: “Consciousness and personality are highly dependent on the brain. Nothing mental happens without something physical happening.”[24] Now Michael Tooley, a philosopher at the University of Colorado at Boulder, has stated five lines of evidence in support of this claim.[25]

  • When an individual’s brain is directly stimulated and put into a certain physical state, this causes the person to have a corresponding experience.
  • Certain injuries to the brain make it impossible for a person to have any mental states at all.
  • Other injuries to the brain destroy various mental capacities. Which capacity is destroyed is tied directly to the particular region of the brain that was damaged.
  • When we examine the mental capacities of animals, they become more complex as their brains become more complex.
  • Within any given species, the development of mental capacities is correlated with the development of neurons in the brain.

Take together, this evidence is much more probable on physicalism, which says that the mind is made only of physical matter, than it is on dualism, which says says that the mind is made of two substances (the physical and the mental). if God exists, God is not in any sense dependent on physical arrangements of matter. So theism entails the existence of at least one unembodied mind. Furthermore, if God wanted to create other minds, he didn’t need them dependent on physical brains.
So the dependence of human minds on brains is evidence against the existence of any being who is supposed to have an unembodied mind, including God. Therefore, the physical nature of minds is evidence favoring naturalism over theism.

Empathy and Apathy

(6) Naturalism is the best explanation for the neurological basis of empathy and apathy, including some moral handicaps.[26]
In many cases, our ability to choose do morally good actions depends upon our having properly functioning emotional capacities, especially empathy, i.e., our ability to identify what someone else is thinking or feeling and to respond to their thoughts and feelings with an appropriate emotion.[27]
We now know, thanks to the relatively new discipline of neuroscience, that certain brain abnormalities cause people to experience less or even no empathy.[28] According to Simon Baron-Cohen of Cambridge University, “There is a consensus in neuroscience that at least ten interconnected brain regions are involved in empathy.”[29] These regions are shown on the slide.
For example, violent psychopaths may know in some abstract sense that their behavior is morally wrong, but utterly lack empathy.[30]
While theism is compatible with a neurological basis for moral handicaps, the fact that at least some moral handicaps can be explained neurologically is much more probable on naturalism than on theism. If theism is true, then that means both 

(a) God creates some human beings with moral handicaps that are not the result of the freely chosen actions of any human being;


(b) These moral handicaps make it more likely that they will harm others.

What moral justification would God have for allowing both (a) and (b) to obtain? This seems utterly surprising and completely random from a theistic, moral point of view, but precisely what we would expect on naturalism (and blind nature is indifferent to the moral consequences of brain abnormalities).[31]

Nonresistant Nonbelief

(7) Naturalism is the best explanation for nonresistant nonbelief (in God).[32]
Imagine you’re growing up in an orphanage and I told you I had met a man who claims to be your father and who really wants a relationship with you. Days, weeks, even months go by but you never actually meet your father. You never get a card, letter, phone call. In fact, the only evidence that your father is alive is my claim that he exists. Why haven’t you heard from him? Perhaps your father is ashamed for abandoning you. Or maybe he’s a prisoner of war and his captors won’t even let him write you. Although you hope your father is alive and wants to meet you, you remain skeptical.
Just as you do not believe your father is alive and wants to meet you, there are people who do not believe that God exists.[33] But notice that, whatever reasons we might invent to explain your earthly father’s absence do not explain their heavenly father’s absence.
At least some of the people who deny God’s existence are “nonresistant” nonbelievers. As philosopher John Schellenberg explains, their nonbelief is “not in any way the result of their own emotional or behavioral opposition towards God or relationship with God or any of the apparent implications of such a relationship.”[34] Such nonbelievers are open to having a relationship with God—in fact, they may even want it—but are unable to have such a relationship. But why, if God exists, does that happen?
On naturalism, blind nature doesn’t care whether anyone believes in God and so the fact of nonresistant nonbelievers is hardly surprising. On theism, however, this fact is very surprising. On theism, we would expect a perfectly loving God to always make a meaningful relationship available to those He loves.


So, in sum, we’ve seen seven lines of evidence that naturalism is true. I also happen to think there is some evidence for theism, but that it is outweighed by the evidence for naturalism.[35] In my other speeches, I will explain why I think this as I respond to Dr. Turek’s arguments.[36]


[1] I owe this definition to Paul Draper.
[2] I owe this definition to Paul Draper.
[3] This definition is similar to, but not identical with, one offered by Paul Draper.
[4] I owe this definition to Paul Draper.
[5] I owe this definition to Paul Draper.
[6] I owe this to Paul Draper.
[7] I owe this jelly bean analogy to Paul Draper. Draper’s full analogy also includes an equal number of yellow jelly beans in both jars, where yellow signifies something that is equally likely to have come from either jar and hence is not evidence that it came from either jar. I have omitted the yellow jelly beans solely in the interest of time.
[8] I owe this definition to Paul Draper.
[9] I owe this definition to Paul Draper.
[10] Paul Draper, “God and the Burden of Proof,” Secular Outpost (July 21, 2014),
[11] Paul Draper, “More Pain and Pleasure: A Reply to Otte” in Christian Faith and the Problem of Evil (ed. Peter van Inwagen, Eerdmans, 2004), 41-54 at 49.
[12] Let N stand for naturalism, T for theism, and F for any of these facts. Using the symbol “Pr(F | H)” to stand for the epistemic probability that F is true conditional upon H, then the claim that some fact is evidence favoring naturalism over theism should be understood as the claim that Pr(F | N) > Pr(F | T).
[13] Jeffery Jay Lowder, “Potential Objections to Swinburne’s Cosmological Argument,” The Secular Outpost (March 17, 2014), Note that here I am using the word “matter” as a way to provide a concrete example of something “physical.”
[14] See Keith M. Parsons, Science, Confirmation, and the Theistic Hypothesis (Ph.D. Dissertation, Kingston, Ontario, Canada: Queen’s University, 1986), 46; Paul Draper, “Evolution and the Problem of Evil” in Philosophy of Religion: An Anthology (3rd ed., ed. Louis Pojman, Wadsworth, 1997), 223-24; and idem, “God, Science, and Naturalism” Oxford Handbook of Philosophy of Religion (ed. William Wainwright, Oxford: Oxford University Press, 2004), 272-303; and Barbara Forrest, “Methodological Naturalism and Philosophical Naturalism: Clarifying the Connection” Philo 3 (2000): 7-29.
[15] Draper 2004.
[16] See Paul Draper, “Evolution and the Problem of Evil” in Philosophy of Religion: An Anthology (3rd ed., ed. Louis Pojman, Wadsworth, 1997), 219-230; cf. Louis P. Pojman, Philosophy of Religion (Mayfield, 2001), chapter 6.
[17] Jerry Coyne, Why Evolution is True (New York: Penguin, 2009), 88.
[18] Coyne 2009, 56.
[19] Draper 1997, 221.
[20] I’m using “virtually simultaneously” as a shorthand way of accounting for the seven literal days described in Genesis 1, in order to contrast that chronology with the sort of geological timescales needed for evolution.
[21] Draper 1997, 224.
[22] Paul Draper, “Pain and Pleasure: An Evidential Problem for Theists.” Nous 23 (June, 1989), 331-350.
[23] Jeffery Jay Lowder, “The Evidential Argument from Physical Minds,” The Secular Outpost (, June 13, 2012.
[24] Paul Draper, “Opening Statement” in William Lane Craig and Paul Draper, Does God Exist? (videotape, West Point, NY, 1996).
[25] Michael Tooley, “Dr. Tooley’s Opening Arguments”  in William Lane Craig and Michael Tooley, The Craig-Tooley Debate: Does God Exist? (, 1994, spotted 25 Jan 99.
[26] Jeffery Jay Lowder, “The Evidential Argument from Physical Minds,” The Secular Outpost (, June 13, 2012.
[27] Simon Baron-Cohen, The Science of Evil: On Empathy and the Origins of Cruelty (New York: Basic Books, 2012), 16.
[28] Baron-Cohen 2012, 39.
[29] Baron-Cohen 2012, 28.
[30] As Baron-Cohen points out, the neurological basis for moral handicaps challenges traditional views about moral responsibility. “If zero degrees of empathy is really a form of neurological disability, to what extent can such an individual who commits a crime be held responsible for what they have done? This gets tangled up with the free will debate, for if zero degrees of empathy leaves an individual to some extent “blind” to the impact of their actions on others’ feelings, then surely they deserve our sympathy rather than punishment.” See Baron-Cohen 2012, 160.
[31] Some theists have pointed out that moral evil, such as fallen angels or demons choosing to do evil, might explain so-called “natural evils.” This argument makes the inverse point: certain natural evils explain at least some moral evil.
[32] J.L. Schellenberg, Divine Hiddenness and Human Reason (Ithaca: Cornell University Press, 1993); idem, 2007.
[33] This sentence, of course, assumes that at least some (if not most) professions of atheism are genuine. Those familiar with intra-Christian debates on apologetic methodologies will notice that I have just ruled out the claim of some (or all?) presuppositionalists, namely, that there are no atheists and instead there are only professed atheists. I agree with  John Schellenberg: “it would take something like willful blindness to fail to affirm that not all nonbelief is the product of willful blindness (even if some of it is).” See J.L. Schellenberg, “What Divine Hiddenness Reveals, or How Weak Theistic Evidence is Strong Atheistic Proof” God or Blind Nature? Philosophers Debate the Evidence (, 2008.
[34] Schellenberg 2008.
[35] It follows from a Bayesian approach to evidence sketched in my first contention that there can be “true evidence” for a false proposition. Consider, for example, people convicted on the basis of eyewitness testimony for crimes they didn’t commit, only to be exonerated years or decades later by DNA evidence. The eyewitness testimony was some evidence for a false proposition (“The defendant is guilty”), but it was greatly outweighed by the DNA evidence against that false proposition. The fact that there can be true evidence for false propositions should serve as a “warning flag” to anyone who wants to claim that there is absolutely no evidence for naturalism (or theism). “There is no evidence for naturalism (or theism)” does not follow from “Naturalism (or theism) is false” or even “I believe naturalism (or theism) is false.”
[36] I am grateful to Paul Draper, John Danaher, Robert Greg Cavin, and Eddie Tabash for helpful comments on a previous version of this speech.

bookmark_borderGenuine Inquiry vs. Partisan Advocacy: Philosophy of Religion vs. Apologetics

Yesterday I blogged about a “recommended apologetics reading” list created by Western Michigan University philosopher Tim McGrew. After several cordial exchanges with Tim, I’ve decided that, despite my best attempts to be charitable, I failed. Contrary to what I had suggested, Tim stated, “I certainly would not recommend that anyone with a serious interest in the truth of Christianity restrict himself to reading only the works I have listed.” I take him at his word, and so I have decided to delete the entire blog post, rather than try to repair it, and replace it with this one.
I want to make a distinction between genuine inquiry, on the one hand, and partisan advocacy, on the other. Consider a central (but far from the only) topic in the philosophy of religion: the existence or nonexistence of God. Consider, for a moment, what it would mean to engage in genuine inquiry regarding God’s existence. If the word “inquiry” means anything at all, surely it means more than “read stuff which confirms the point of view you already hold.” It should include, at a minimum, reading opposing viewpoints, not with the goal of preparing pithy one-liners for debates, but with the goal of actually trying to learn something or consider new ways of looking at old topics. For professional philosophers, I would imagine that inquiry would also include trying to “steel man” your opposition, i.e., trying to strengthen the arguments for your opponent’s position. It might even include publishing arguments for a position you do not hold and even reject.
In contrast, partisan advocacy is, well, exactly what it sounds like it is. Much like an attorney hired to vigorously defend her client in court, a partisan advocate isn’t interested in genuine inquiry. To the extent a partisan advocate reads the “other side” at all, she does so in the same way presidential candidates try to find out the “truth” about their opponent under the guise of “opposition research.” So, for example, if a partisan advocate were to create a reading list about God’s existence, they would compile a list of recommended resources which either exclusively or overwhelmingly promoted a certain point of view and without even a hint that a balanced inquiry should be taken.
As suggested by the subtitle of this post, if we apply the genuine inquiry vs. partisan advocacy distinction to religion, I think we get the distinction between (an ideal) philosophy of religion vs. apologetics.
Now, this raises an interesting question.  At what point is a person, especially a professional philosopher, entitled to say this: “Genuine inquiry is nice and all, but viewpoint X is such obvious nonsense that the time for inquiry is over. After all, no geologist engages in ‘genuine inquiry’ about whether the earth is flat. So why should we treat theism (or atheism) any differently?”
I am not sure about the ‘full’ answer to that question, but I think at least part of the answer has to consider two points.
First, I think the current state of professional opinion is relevant. Surely part of the reason no one engages in genuine inquiry about the flat earth hypothesis is the fact that there are no competent geologists who endorse it. In contrast, among philosophers generally and philosophers of religion specifically, there are equally qualified authorities on both sides.
Second, I think the concept of intrinsic probabilities can play an important role here. I’m a naturalistic atheist, but I’m fully convinced by Paul Draper’s theory of intrinsic probability, which shows that naturalism and supernaturalism have equal intrinsic probabilities. While theism is a specific version of supernaturalism (and so is less intrinsically probable than naturalism), its intrinsic probability is not infinitesimal. Furthermore, not only does theism have a non-negligible intrinsic probability, there is evidence in its favor. It seems to me that if a theory (1) has a non-negligible intrinsic probability; (2) has evidence in its favor; and (3) is held by significant percentage of philosophers, not to mention the general population, then that theory is worthy of genuine inquiry. And notice that these same points apply to atheism or naturalism, which is why theists should also engage in genuine inquiry.

bookmark_borderDoes “Science” Make Theism Likelier than Atheism?

Victor Reppert recently linked to an article on the blog Saints and Sceptics (S&S), Why Science Makes Theism Likelier than Atheism.” In this blog post, I’m going to critically assess that article.
1. What is the Evidence to be Explained?
S&S begin their article as follows:

Should we view the order of the universe, and our ability to comprehend that order, as evidence of God?

This question suggests two related but independent items of evidence to be explained:

E1. The universe is orderly.
E2. The universe contains intelligent beings able to comprehend that order.

Regarding E1, S&S don’t clarify or explain what they mean by phrases like “the order of the universe” or, elsewhere, “the high degree of order” of the universe. In order to be charitable, I’m going to “steel man” their argument by assuming they are appealing to something similar to what Christian philosopher Richard Swinburne calls the “arguments from spatial and temporal order” in his book, The Existence of God.  The argument from temporal order appeals to the fact that “there are regular successions of events, codified in laws of nature.”[1] The phrase “regular succession of events” is key; this is why, I suppose, Swinburne calls it the argument from temporal order. In contrast, the argument from spatial order appeals to the fact that, given our universe conforms to simple, formulable, scientific natural laws, “our bodies are suitable vehicles to provide us with an enormous amount of knowledge of the world and to execute an enormous variety of purposes in it.”[2] This “steel man” interpretation seems highly charitable, since E1 seems to correspond with Swinburne’s argument from temporal order, whereas E2 is very similar to Swinburne’s argument from spatial order.[3]
Accordingly, we may clarify E1 as follows.

E1′. The universe conforms to simple, formulable, scientific laws.

With the evidence to be explained sufficiently clarified, let’s unpack their argument.
2. What, Precisely, Is the Argument?
Before I can turn to the logical structure of S&S’s argument, let’s first review some notations which will make it easier to summarize the argument in a concise form.

Pr(x): the epistemic probability of any proposition x
Pr(x | y): the epistemic probability of any proposition x conditional upon y
“>!”: “is much more probable than”
“>!!”: “is much, much more probable than”
T: theism
A: atheism. A is logically equivalent to ~T.

The first premise of the argument is a simple statement of E1′:

(1) E1′ is known to be true, i.e., Pr(E1′) is close to 1.

Let’s now return to S&S:

Let’s start with atheism. From an atheistic perspective, there doesn’t seem to be any explanation for the order in the universe; it would just be a brute fact or a ‘happy accident’ as Polkinghorne puts it.
But that doesn’t seem good enough. In the absence of an explanation, we would have no reason to expect the high degree of order that we find. But does theism fare any better? To many it seems very likely that if the universe is the product of an intelligent mind, it would exhibit order.  …

So the second premise of the argument seems to be:

(2) An orderly universe is antecedently much more probable on the assumption that theism is true than on the assumption that atheism is true, i.e., Pr(E1′ | T) > Pr(E1′ | A).

The third premise is a simple statement of the evidence E2.

(3) E2 is known to be true, i.e., Pr(E2) is close to 1.

Returning to S&S:

But does theism make an intelligible universe – especially one which is governed by comprehensible laws and which can described by mathematics – any more likely? …
If our minds are the result of design we could rely on them to discover the truth. Rational rulers used laws to govern – and God was the ruler of the universe. And it would not be surprising to discover that mathematics could describe the universe if the divine mind and human minds were analogous in at least some respects. Finally if the universe is created by a good God, he would not systematically deceive us. In light of these considerations, Kepler and his fellow scientists were surely right to think that there is much more reason to expect an intelligible universe if there is a God than if there is not.

So the next premise seems to be:

(4) An intelligible universe is antecedently much more probable on the assumption that theism is true and an orderly exists than on the assumption that atheism is true and an orderly universe exists, i.e., Pr(E2 | T & E1′) > Pr(E2 | A & E1′).

Finally, S&S concludes:

So it is obvious that any complex, valuable, beautiful and intelligible state of affairs – including our universe – is much, much more likely given theism than chance.

And so the conclusion of their argument is:

(5) Therefore, theism is a much, much more likely explanation for the order and intelligibility of the universe than chance, i.e., Pr(T | E1′ & E2)  >!! Pr(chance | E1′ & E2).

We are now in a position to concisely state the argument in its logical form.

(1) Pr(E1′) is close to 1.
(2) Pr(E1′ | T) > Pr(E1′ | A).
(3) Pr(E2) is close to 1.
(4) Pr(E2 | T & E1′) > Pr(E2 | A & E1′).
(C) Therefore, Pr(T | E1′ & E2)  >!! Pr(chance | E1′ & E2).

Let us now turn to evaluating the strength of this argument. While I have many objections to this argument, let me present just four.
3. First Objection: The Argument Ignores Intrinsic Probabilities
This argument is a deductive argument about inductive probabilities. As stated, however, the argument is incomplete. It does not contain any premises regarding the prior probabilities of theism and atheism. But Bayes’ Theorem shows that posterior or final probabilities are a function of two things: prior probability and explanatory power. S&S write much about the latter, whereas they are completely silent about the former. This invalidates their argument. It’s possible that (1) – (4) could all be true and yet the conclusion, (C), still might not follow if the prior probability is extremely low.
In order to repair the argument, S&S would need to add a premise to their argument which explicitly addresses the prior probabilities of theism and atheism. Now, applying the concept of a “prior probability” to a metaphysical hypothesis like theism is tricky. It isn’t clear from S&S’s article which propositions they would include in their background information for the purpose of assessing a prior probability, and I do not know of a non-controversial way to choose such propositions. Fortunately we don’t have to solve that problem; another option is to replace “prior probability” with “intrinsic probability.” As the name implies, an intrinsic probability is the probability of a hypothesis based solely on intrinsic factors relating to its content (i.e., what it says); it has nothing to do with extrinsic factors, such as the relationship between a hypothesis and the evidence to be explained.
In an attempt to “steel man” S&S’s argument, I propose that we adopt Paul Draper’s theory of intrinsic probability, which says that the intrinsic probability of a hypothesis is determined by its scope, its modesty, and nothing else. Draper explains modesty and scope as follows.

a. Modesty: The modesty of a hypothesis is inversely proportional to its “content”—to how much it says. Hypotheses that say less—for example, because they make fewer claims or less specific claims or claims that are narrower in scope—are, other things being equal, more likely to be true than hypotheses that say more.
b. Coherence: The coherence of a hypothesis depends on how well its components fit together.
c. If we abstract from all factors extrinsic to a hypothesis, then the only thing that could affect the epistemic probability of that hypothesis is how much it says and how well what it says fits together. No other factors affecting probability could be intrinsic to the hypothesis.

Using these criteria, we’re now in a position to compare the intrinsic probabilities of theism and atheism. Before we do that, however, we need to start with the intrinsic probabilities of naturalism and supernaturalism. Here’s Draper:

4. The intrinsic probabilities of naturalism and supernaturalism
a. Naturalism is the statement that the physical world existed prior to any mental world and caused any mental world to come into existence.
b. Supernaturalism is the statement that the mental world existed prior to any physical world and caused any physical world to come into existence.
c. Otherism is the statement that both naturalism and supernaturalism are false.
d. Naturalism and supernaturalism are equally probable intrinsically because they are equally modest and coherent. Since the intrinsic epistemic probability of otherism is greater than zero, naturalism and supernaturalism are each less probable intrinsically than their denials. (So both naturalists and supernaturalists bear a burden of proof and that burden is equal.)
5. The intrinsic probabilities of theism and atheism
a. Theism is a very specific version of supernaturalism and so is many times (i.e. at least 10 times) less probable intrinsically than supernaturalism.
b. Naturalism is a specific version of atheism and so is many times less probable than atheism.
c. Thus, since naturalism and supernaturalism are equally probable intrinsically, it follows that atheism is many times more probable intrinsically than theism, which entails that atheism has a high intrinsic probability (certainly higher than .9) while theism has a very low intrinsic probability (certainly lower than .1)….

Let me introduce a bit more notation:

Pr(|x|): the intrinsic probability of any proposition x

Using that notation, we are now in a position to add the missing premise to S&S’s argument:

(5) Atheism is many times more probable intrinsically than theism, i.e., Pr(|A|) > .9 >!! Pr(|T|) < .1.

Unfortunately for S&S, however, it is far from obvious that the evidence to be explained, E1′ and E2, outweigh the very low intrinsic probability of theism. Accordingly, it’s far from obvious that the conclusion, (C), follows from premises (1)-(5).
4. Second Objection: Pr(E1′ | A) May Be Inscrutable
My second objection to S&S’s argument is that Pr(E1′ | A) may be inscrutable. If it’s inscrutable, then they can’t compare Pr(E1′ | T) to Pr(E1′ | A). Accordingly, the truth of (2) would be unknown. While I’m open to the possibility that (2) is true, I cannot figure out a way to defend it.
Why think Pr(E1′ | A) is inscrutable? In the context of E1′, A is a catch-all hypothesis. A is logically equivalent to A conjoined with all possible explanations for temporal order in the universe apart from theism.[4] For example:

A1: A is true, and the explanation for temporal order in the universe is naturalistic explanation #1.
A2: A is true, and the explanation for temporal order in the universe is naturalistic explanation #2.

An: A is true, and the explanation for temporal order in the universe is naturalistic explanation #n.

That’s a lot of potential explanations. Accordingly, this constitutes a prima facie reason to be skeptical of the claim that Pr(E1′ | A) can be known well enough to support a comparative claim such as (2). The only way to reject this prima facie reason would be to identify some intrinsic feature of A which either ruled out a naturalistic explanation for E1′ or which made such an explanation antecedently less likely than it would be on T. Is there such a reason?
Let’s reconsider part of what S&S write in support of (2):

From an atheistic perspective, there doesn’t seem to be any explanation for the order in the universe; it would just be a brute fact or a ‘happy accident’ as Polkinghorne puts it.

By “brute fact,” I assume that S&S mean “a fact which has no explanation.” By “happy accident,” I assume that Polkinghorne means due to chance. But “brute fact” and “happy accident” hardly constitute an exhaustive set of the possibilities. Let me add just one more to the list: factual necessity. Metaphysical naturalism (as defined in the Draper quote, above) is antecedently very probable on the assumption that atheism is true. If metaphysical naturalism is true, then it seems highly plausible that physical reality — whether that consists of just our universe or a multiverse — is factually necessary.  If physical reality is factually necessary, it seems highly plausible that temporal order could also be factually necessary. But if temporal order is factually necessary, then it is just factually necessary and there is nothing for atheism to explain.
Admittedly, the hypothesis, “our universe and its laws are factually necessary,” is highly speculative and not known to be true. But, to paraphrase a point once made by CalTech physicist Sean Carroll, theists like S&S are the ones proposing bizarre thought experiments involving the fundamental laws of nature. So we have to consider such speculative possibilities due to the very nature of the topic and the argument. In any case, this much is clear: S&S give no evidence of having even considered, much less addressed, such a possibility.
5. Third Objection: The Conclusion Confuses Atheism with Chance
My third objection is closely related to my point about factual necessity.

So it is obvious that any complex, valuable, beautiful and intelligible state of affairs – including our universe – is much, much more likely given theism than chance.

The conclusion of the argument does not follow from the premises because the conclusion compares theism to chance, not theism to atheism. But, as we’ve just seen, atheism functions as a catch-all hypothesis. Atheism is compatible with the proposition, “The universe and its temporal order are factually necessary.” N.B. That proposition denies that the order of the universe is due to chance. And S&S provide no reason to think that chance is antecedently much more probable on atheism than factual necessity.
6. Fourth Objection: The Argument Commits the Fallacy of Understated Evidence
As is the case with E1′, I’m open to the possibility that E2, either by itself or when conjoined with E1′, is evidence favoring theism over atheism.[5] In other words, I’m open to the idea that (4) is true. I don’t think S&S have successfully shown this, however. Rather than pursue that objection here, however, I’ll leave that as an exercise for interested readers. Instead, I want to pursue a different objection: even if (4) were true, it would commit the fallacy of understated evidence.
Let’s suppose, for the sake of argument, that the intelligibility of the universe really is evidence favoring theism over atheism. Given that the universe is intelligible, the fact that so much of it is intelligible without appealing to supernatural agency is much more probable on naturalism than on theism. (I’ve defended this argument at length elsewhere, so I will refer interested readers to that defense.) Since naturalism entails atheism, it follows that this evidence favoring atheism over theism.
The upshot is this: even if the intelligibility of the universe is evidence favoring theism, there is other, more specific evidence relating to its intelligibility which favors naturalism (and hence atheism) over theism. It’s far from obvious that the former outweighs the latter.
7. Conclusion
As we’ve seen, there are four good objections to S&S’s claim that science makes theism more likely than atheism. I conclude, then, that S&S’s argument is not successful.
[1] Richard Swinburne, The Existence of God (second ed., New York: Oxford University Press, 2004), p. 153.
[2] Swinburne 2004, p. 154.
[3] The main or only difference between Swinburne’s argument from spatial order and S&S’s E2 is that the former also appeals to our ability “to execute an enormous variety of purposes” in the world, whereas the latter does not.
[4] Herman Phillipse, God in the Age of Science? A Critique of Religious Reason (New York: Oxford University Press, 2012), 258.
[5] For what it’s worth, I think E2 is much more promising than E1′ as a potential source of theistic evidence.

bookmark_borderHere’s One Way to Resist Naturalistic Arguments: Lack Belief that Matter Exists!

A Christian apologist writing under the pseudonym ‘InvestigativeApologetics’ stated the usual objection to atheism, namely, that it’s impossible to prove or give evidence for the non-existence of God.

The fact is that atheists who yell that “there is no evidence for God (or Christianity)” are protesting too much, so to speak, and they are, in fact, projecting the weakness of atheism onto theism. For truth be told, it is atheism, at least when in its wide and positive sense, that is the view for which there is no evidence or argumentation that could establish its position. (LINK)

I responded as follows:

Yawn. InvestigativeApologetics seems completely oblivious about the ways to establish the truth of atheism. 

LINKS: herehere

InvestigativeApologetics then doubled down on his original claim, but with a very novel justification.

Yawn all you like. I am intimately familiar both with those two links and with the various Evidential Arguments that you present at the Secular Outpost. In fact, funny enough, it was your arguments that inspired me to look into this matter and come to the conclusion that I did concerning the un-evidenced nature of atheism (when viewed broadly and positively).

Now, obviously, I cannot show this conclusion in this particular comment (although further comments may follow) and I am simultaneously–at this point in my life–beyond caring whether people are swayed by my points or not (for convincing a flesh-and-blood person is not the same as having a convincing argument). However, let me just make a few quick points:

1) First, I am not saying that we must prove that a god does not exist with certainty in order to be rational to believe that a god(s) does not exist. Rather, I am saying that the atheist cannot even show that it is more probable than not that a god does not exist…at least not without begging the question in a substantial number of ways that the theist or skeptic need not grant.

2) For example, consider all the evidential arguments that you present on the Secular Outpost in light of the Likelihood Principle (that a data/observation counts as evidence for Hypothesis 1 over Hypothesis 2 if the data/observation is more likely or expected on Hypothesis 1 than on Hypothesis 2):

The Evidential Argument from Scale (AS) – Given the kind of being described in my first comment, no specific scale of the universe would count as evidence against its existence, and all “scale types” would be equally expected on both naturalism and that form of theism. Thus, no evidential support for naturalism (and I know that you don’t fully or strongly endorse the argument from scale, but I wished to present it anyway). 

b. The Evidential Argument from the History of Science (AHS) – This argument was ripped apart in a past discussion that I remember (with Crude and CL and others, I believe…I’m sure you will disagree, but that is not surprising given that philosophy is a discipline of disagreement), and it has (at my last count) at least 10 flaws, but its worst flaw is that it assumes both that there is such a thing as “matter” and that there is such a thing as a “naturalistic” cause (or explanation), but neither of these need be accepted by the theist or skeptic, either of whom could be an immaterialist (or a-matterist) and/or an occasionalist (where God is the only true cause). So your argument rests on an assumption that need not be conceded, and hence, the argument is flawed from the start. It is also circular given that you need to deal with the objection from the occasionalist, but to do that, you cannot assume a natural cause, which is what the occasionalist denies; you would either have to disprove occasionalism or disprove the existence of any god through other means, but this, in turn, makes your argument redundant. So the argument is either redundant or begs the question. Not a good state for an argument to be in. Furthermore, even if the existence of “naturalistic” explanations was conceded, it would still be the case that if a deist non-interventionist god existed, we would expect all explanations to be naturalistic even on this type of deism, and so again, there is no evidential value in favor of naturalism or deism with this argument as naturalistic explanations would be equally likely on both worldviews.

1. InvestigativeApologetics’ comments about the AHS are confused. Theism,’ as I have defined it, is the ‘core‘ explanatory hypothesis. Sectarian doctrines like occasionalism and non-interventionism are auxiliary hypotheses, viz., theism does not entail occasionalism or non-interventionism but is compatible with both. They are at, at best, uncertain. The probability calculus specifies how we should deal with uncertain auxiliary hypotheses in a way that conforms with the pattern of probability relations specified by Bayes’ Theorem. I explain this here. What IA needs to do is provide an antecedent reason on theism for expecting that either or both of these auxiliary hypotheses are significantly more likely than their denials. Otherwise, the logically correct conclusion is to dismiss these objections as ad hoc, “just so” stories invented solely to avoid the conclusions of the arguments. “Both worldviews” might have roughly equal explanatory power, but naturalism would trump deism by virtue of having a greater intrinsic probability.
2. More important, a careful reading of my arguments will reveal that my arguments need not presuppose that material objects exist.  Supernaturalism (or “source idealism”) can be defined in a way that is neutral between dualism and idealism.  (The hypothesis that the original causes of any material objects that exist are immaterial does not entail that material objects exist.)  Similarly, naturalism or “source physicalism” can be defined in a way that is neutral between dualism and materialism.  Notice too, that even if my particular definition of supernaturalism implies the existence of material objects, that is compatible with “identity idealism”, which is far more plausible than eliminative idealism, just as identity materialism is far more plausible than eliminative materialism.  (Berkeley was an identity idealist, for example.  He believed that physical objects exist, but thought they were collections of ideas.) (I owe this point to Paul Draper.)

c. The Evidential Argument from Biological Evolution (ABE) / The Evidential Argument from Physical Minds (APM) / The Evidential Argument from Evil: The Biological Role of Pain and Pleasure (AE: APP) / The Evidential Argument from Evil: The Flourishing and Languishing of Sentient Beings (AE: AFL) / The Evidential Argument from Evil: The Self-Centeredness and Limited Altruism of Human Beings (AE: AVV) – See Point (a) – Again, none of these arguments hold any evidentiary weight against a non-interventionist god and so do not support naturalism over such a deism given that all these facts would be equally likely on naturalism or deism.

Now, to be precise, my “arguments for naturalism” are really arguments against theism, though in some sense they are of course both.

Now, you could, of course, try to claim that aspects of prior probability or modesty/coherence (from Paul Draper’s ‘Burden of Proof’ Argument, which I know you support) might make atheistic-naturalism more rational or more likely than some type of theism. But again, there are numerous problems with such maneuvers. First, prior probabilities are notoriously difficult to establish objectively, and I, on that basis alone, I would be suspicious of any argument, by an atheist, which just happens to show that atheism (or atheistic-naturalism) has a higher prior probability than theism.

IA knows very well that suspicion is not an argument. And notice that IA gives no reason to doubt that intrinsic probabilities should be determined solely by scope and coherence. Furthermore, he neglects to mention that Draper’s theory of intrinsic probability does result in the conclusion that naturalism and supernaturalism have equal intrinsic probabilities. Once that fact is taken into consideration, it becomes clear that Draper’s theory is not biased against supernaturalism. The fact that theism has a smaller intrinsic probability than supernaturalism follows directly from the definitions of supernaturalism and theism. Theism entails supernaturalism but supernaturalism does not entail theism. So the probability of theism cannot be any greater than the probability of supernaturalism but could be less. This is basic, non-controversial set theory.

Second, in all your arguments (and your priors) you begin with the assumption that materialism—in the sense of metaphysical matter actually existing—is true, but I do not concede this assumption (being an a-matterist and thus lacking a belief in the existence of matter) and so this must be proven before any one of your arguments gets off the ground and before you can even set the prior probabilities that you want. Third, modesty and coherence does not favor naturalism, but rather a type of Berkelian immaterialism, for it is that view that makes the least assumptions about reality (only thinking things exist, which we cannot deny, and is thus the most modest) while remaining coherent (and it is arguable that atheistic-naturalism even is coherent), so Draper does not help you much.

Addressed above.

Fourth, even if we grant the existence of matter, given the fact that a “material god” could exist, and given that a good case could be made that the prior probability of a “material god” existing is either just as good or better than the prior probability of straight atheistic-naturalism (for consciousness, language, life, would have a higher probability of existing given the existence of a material god than given just straight atheistic-naturalism), then, once again, your arguments run into trouble.

What is a “material god”? The word “material” tells us that such a being is composed of matter. The word “god,” I gather, is supposed to tell us that such a being has supernatural powers or abilities. The hypothesis that such a being exists is a very specific version of supernaturalism and so, like theism, has a smaller intrinsic probability than supernaturalism and naturalism. (The more a hypothesis claims, the more ways there are for that hypothesis to be false and so the lower the intrinsic probability.) So-called ‘theistic evidences’ — such as consciousness, language, life, and so forth — determine the explanatory power of the ‘material god’ hypothesis, not its intrinsic probability. Furthermore, notice that IA lists only alleged theistic evidences. It seems rather one-sided to estimate the probability of a material god existing by considering only theistic evidences, while ignoring naturalistic evidences (such as pain and suffering, evolution, nonresistant nonbelief, mind-brain dependence, and so forth). Once the evidence is fully stated, it’s doubtful that IA’s “material God” exists.

Now, I am certain that you might scoff at certain proposals that I have put forward (for example, immaterialism or occasionalism) as being not worthy of consideration. And that’s fine. But my point is this: I do not need to concede to the very assumptions which are latent in so many of the arguments that you put forward, and the moment I do not concede to those assumptions, not only do your arguments lose nearly all their force (if not all), but you actually have the burden to prove the things that you are asserting. And demonstrating such things (such as the actual existence of matter, for example) is a very difficult task to say the least. Furthermore, until and unless you do demonstrate the existence of these things you just essentially assumed, I could readily contend that you hold to them with little more than blind faith. And so these are just some of the brief reasons why, when atheistic arguments are thoroughly deconstructed, and when we realize the various underlying assumptions that they make—assumptions which we need not grant—and when we also understand that the atheist is literally denying the existence of all reasonably possible gods, which could and would include a god such as a non-interventionist one, then we can begin to understand why the atheistic position, when viewed broadly and positively, lacks any evidence for its claim. 

I’m not sure about “scoffing,” but I will say this. If the best response a person has to my arguments is to doubt or deny the existence of matter, then I’m feeling pretty good about the arguments. This must be how Christians feel when atheists use certain far-fetched objections.(“If this is the lengths they have to go to in order to deny the argument, then let them have it.”)

bookmark_borderWilliam Lane Craig on the Prior Probability of Theism and the Fine-Tuning Argument

One objection to fine-tuning arguments for God’s existence goes like this: simply showing that so-called ‘fine-tuning’ is more probable on theism than on atheism isn’t enough to show that God exists. One must also take into account the prior probability of theism.
William Lane Craig responds to this objection in a recent Q&A on his website. He begins:

Your professor’s objection will be more comprehensible if we put it into the context of the probability calculus. Let’s compare the probability of theism vs. atheism relative to the fine-tuning of the universe. Let G stand for the hypothesis that God exists and ¬G for the hypothesis that God does not exist. Let FT stand for the fine-tuning of the universe. The comparative probabilities will be computed as follows:

Now what you argued in your paper was that the third ratio favored theism. The fine-tuning of the universe is considerably more probable given God’s existence than given God’s non-existence. The evidence is therefore strongly confirmatory of theism. So far so good!
What your professor wants to say is that your argument still does not prove that God’s existence is more probable than His non-existence relative to the fine-tuning of the universe. That is the first ratio on the left-hand side of the equation. In order to show that this ratio favors theism, you also need to show that the prior probability of God’s existence is not greatly lower than the prior probability of God’s non-existence. That’s the middle ratio above. The idea here is that the greater explanatory power of a hypothesis can be offset by the enormous improbability of the hypothesis itself.

So far, so good. Craig now turns to his responses.

There are two responses you might make to this objection. First, you might deny that you were trying to prove that the first ratio favors theism. You might simply rest content with showing that the evidence we have is hugely confirmatory of theism.

Yes, a proponent of a ‘fine-tuning’ argument for God’s existence could respond that way. But then they would just be admitting that the objection is correct. That’s about as ineffective a response as possible.

Collins, for example, points out that in science we often do not have any way of estimating the prior probability of a hypothesis, and so we simply rest with arguments showing a hypothesis’ greater explanatory power. It may be that the prior probability of the hypothesis is just inscrutable.

While that may be true of some unspecified, generic hypothesis, this isn’t true of theism, atheism, or naturalism. Craig evinces no awareness of Purdue University philosopher Paul Draper’s work on intrinsic probability, which functions as a kind of prior probability and is particularly useful for ‘ultimate’ metaphysical hypotheses like theism and naturalism.

You might even point out that in order to resist your confirmatory argument on behalf of theism, it’s the atheist who has the burden of proof of showing that theism is considerably more improbable than atheism.

Again, Craig’s unawareness of Draper’s work on intrinsic probability comes back to haunt him. This challenge can be easily met. Craig needs to interact with Draper’s argument that metaphysical naturalism, which entails atheism, has an objective intrinsic probability which is greater than that of theism.

Second, you could argue that theism is not intrinsically much more improbable than atheism. For the prior probabilities Pr (G) and Pr (¬G) are not, despite appearances, computed in a vacuum. Rather these probabilities are computed relative to our background information about the world. You subtract the information about the fine-tuning of the universe from what we know about the world, and whatever is left is our background information. That information will include the evidence featured in all the other theistic arguments, such as the contingency of the universe, the beginning of the universe, the objectivity of moral values and duties, the applicability of mathematics to the physical universe, intentionality, the facts concerning the resurrection of Jesus, and so forth. I think that we should be prepared to argue that the prior probability of theism is much greater than that of atheism relative to our background information. In that way we successfully argue that theism is much more probable than atheism given the fine-tuning of the universe.

First, this reply just pushes the problem back a step. I fully support the idea of cumulative cases, but what Craig seems to forget is that all cumulative cases have to start somewhere. Whatever he wants to use as his first piece of evidence must confront the fact that theism has a lower intrinsic probability than naturalism. For example, if he wants to make the contingency of the universe his first argument, he has to confront it there.

Second, many of Craig’s arguments, including his fine-tuning argument, are textbook examples of arguments which commit the fallacy of understated evidence.

Third, Craig also ignores the fact that there are other lines of evidence, independent of those related to his understated evidence, which favor naturalism over theism.

bookmark_borderMy Recent Call-In Segment with Trent Horn on Catholic Answers Live

A few weeks ago Catholic Answers had a two hour radio show devoted to taking calls from nontheists only. I was the last caller. I had the privilege of having a brief, but very enjoyable and intellectually stimulating conversation with Trent Horn. A fan recently made me aware of a YouTube recording of it.

Trent, if you’re reading this, thanks again for being such a gracious host. I look forward to talking with you again in the future!

bookmark_borderYahweh vs. Thor

On my Twitter timeline, I saw the following:

“Atheism does not require certainty. But we can be as certain the Christian god does not exist as Christians are that Thor does not exist.”

If I were to reword the tweet, albeit in a way that is too long for twitter, I would have offered something like this:

“Atheism, when defined as the belief that God does not exist, does not require certainty. Rather, like any other belief, people can hold this belief with varyingdegrees of belief. The atheist’s degree of belief that the Christian god does not exist is the same or virtually the same as the atheist’s degree of belief that Thor does not exist.”

Okay, I said it was wordy.

What to make of this proposed rewording? Three thoughts.
1. On the assumption that atheism is true, it doesn’t follow that Thor and the Christian god have the same (im)probability. It’s easier to illustrate this point using metaphysical naturalism, which entails that no supernatural beings exist. Let’s say the naturalist’s degree of belief that naturalism is true is 0.95. It follows, then, that the maximum degree of belief a naturalist could assign to any supernatural being, including Thor and the Christian god, is 0.05. (This is because both Thor and the Christian god entail that supernaturalism is true; thus neither Thor nor Yahweh can be more probable than supernaturalism.) But it doesn’t follow that the naturalist’s degree of belief in the existence of Thor or the Christian god would actually be 0.05; it could be (and probably is) less than that amount. Why? Because Thor and the Christian god make many more specific claims than ‘mere’ supernaturalism.
2. If one adopts Draper’s theory of intrinsic probability–which says that a proposition’s intrinsic probability is determined by modesty, coherence, and nothing else–then the naturalist (who, by definition, is an atheist) would probably say that the intrinsic probability of Thor and Yahweh are roughly equal if not exactly equal. (I have to confess I haven’t studied Norse mythology, so I don’t know if that would be correct or not. It wouldn’t surprise me in the least if it were true, however.)
3. Turning to the final probability of Thor and Yahweh, final probability is determined by intrinsic probability and the likelihood of the evidence. In order to defend the claim that Thor and Yahweh have the same final probabilities, one would need to evaluate the evidence for both. I don’t have much to say about this other than one point: atheists can believe that both Yahweh and Thor have low, even ridiculously low, final probabilities without believing they are equal.
For example, it’s possible that a naturalist who has studied both Norse mythology and Christian apologetics might reach the following conclusions:
(a) Both Thor and Yahweh have very low (but not hopelessly low) intrinsic probabilities.
(b) The likelihood of the evidence relevant to Thor is 0.01.
(c) The likelihood of the evidence relevant to Yahweh is 0.04.
(d) Therefore, while the evidence for Yahweh is four times as strong as the evidence for Thor, the evidence for both is pathetically weak and hence both have extremely low final probabilities.
Given the low intrinsic probabilities of both Thor and Yahweh, however, the naturalist might justifiably believe an investigation of the Thor-specific and Yahweh-specific evidence isn’t worth his or her time. This might especially be the case if the naturalist believes he or she has strong evidence against mere supernaturalism.
This point leads to another rewording of the tweet.

“Atheism does not require certainty. But highly specific supernatural claims, like “Thor exists” and “Yahweh exists,” are so intrinsically improbable that an investigation of the evidence isn’t worth the effort.”

bookmark_borderDraper on Pain and Pleasure: Part 4

This post is part of a series on Paul Draper’s classic version of the evidential argument from evil. In the previous entry, I summarized Draper’s refutation of three theodicies which might be used as an objection to the claim that HI explains the facts about the biological role of pain and pleasure much better than T does. In this post, I’m going to review the final section of Draper’s classic 1989 article on the evidential argument from evil.
1. Darwin’s Argument from Evil
In the final section of his paper, Draper sets up an analogy between Darwin’s evidential argument against special creationism and Draper’s evidential argument against theism. It is worth quoting Draper’s remarks about Darwin’s argument in full.

“Darwin argued that his theory of the evolution of species by means of natural selection explains numerous facts (e.g., the geographical distribution of species and the existence of atrophied organs in animals) much better than the alternative hypothesis that each species of plant and animal was independently created by God. (Let us call this latter hypothesis “special creationism.”) Darwin’s results were significant partly because special creationists at Darwin’s time did not have nor were they able to obtain evidence favoring special creationism over evolution theory that outweighed or at least offset Darwin’s evidence favoring evolution theory over special creationism. For this reason, many theists, while continuing to believe in creationism, which is consistent with Darwin’s theory, rejected special creationism. And those theists who were familiar with Darwin’s arguments and yet remained special creationists did so at a cost: their belief in special creationism was no longer an epistemically rational one.”

Draper says that the significance of his evidential argument from evil is to be determined in an analogous way, viz., it depends upon whether theists have evidence favoring T over HI, evidence which could offset his evidence O favoring HI over T. (N.B. Draper points out this evidence could be propositional evidence, non-propositional evidence, or both.) If a theist confronted with his argument lacks and cannot find such offsetting evidence, Draper argues, the theist “cannot rationally continue to believe that theism is true.”
2. Prospects for Theistic Offsetting Evidence
Draper then offers four reasons for doubting the theist will be able to find such offsetting evidence. It is interesting to compare those reasons (offered in 1989) with the positions Draper has adopted later in his career.
(1) In his 1989 paper, Draper claims that it is “doubtful that it could be shown that HI is ad hoc or that T is intrinsically more probable than HI.” It is noteworthy that, long after his 1989 paper, Draper finally started developing his new theory of epistemic probability. When that theory of epistemic probability is applied to HI and T, it yields the result that the intrinsic probability of HI is significantly greater than T.
(2) Next, Draper argued in 1989 that “Traditional and contemporary arguments for theism are far from compelling.” Since 1989, Draper has gone on record as stating that several facts are evidence favoring T over naturalism (which entails HI). Indeed, he even published a paper arguing that the argument from moral agency is “in the same league” as his evidential argument from evil. But Draper also usefully identified a new fallacy of inductive reasoning he calls the “fallacy of understated evidence.” According to Draper, many (most?) evidential arguments for theism, including his own argument from moral agency, commit the fallacy of understated evidence.
(3) Draper’s third reason (in 1989) for thinking that the theist’s search for offsetting evidence will be difficult is this.

Many traditional and contemporary arguments for theism … may not solve the theist’s position even if they are sound and recognized by the theist to be so. For they at most purport to show that an omnipotent and omniscient being exists–not that the being is morally perfect.”

This point seems (to this writer) as true in 2014 as it was in 1989.
(4) Finally, Draper argues (in 1989) that religious experience doesn’t solve the problem identified in (3): “Religious experience is ambiguous with respect to the moral attributes of the creator.” Furthermore, he notes that theistic justification derived from theistic experiences is offset by atheistic justification derived from “experiences of indifference.” Not only is this yet another example of the fallacy of understated evidence, but Draper wrote an article in 1992 on the evidential value of religious experience. In that article, Draper concluded that three specific facts about religious experience favor atheism over T.

bookmark_borderDraper’s Reply to Welty

Philosopher Greg Welty wrote a brief response to Paul Draper’s brief summary of his position regarding God and the burden of proof. Here is Draper’s reply to Welty.

Greg Welty has written an interesting reply to my post on “God and the Burden of Proof”.  He does a very good job of explaining my argument (for which I am grateful), but then he gets into some trouble.  My reason for pointing this out is that it will, I think, help to clarify my argument.
Crucial to my argument is that theism is a specific version of supernaturalism and so is intrinsically less probable than supernaturalism.  Welty disagrees.  He says that “supernaturalism could be one among many ways to be a theist . . . . For instance, perhaps the only things that exist are (immaterial) perceivers and their ideas, and there is no matter, and God is the most important Perceiver of all. That would be a form of theism, but it wouldn’t be supernaturalism (as defined by Draper).”  On the contrary, idealist versions of theism are in fact forms of supernaturalism as I define that term.  I define “supernaturalism” as the view that the mental world existed prior to ANY physical world and caused ANY physical world to come into existence.”  On this definition, a supernaturalist could be a dualist about the mental and the physical.  But she could also be an idealist.  She could, for example, be an identity idealist like George Berkeley, who believed that physical objects exist but are just collections of ideas.  In other words, for identity idealists, the physical is a subtype of the mental.  A supernaturalist could also be an eliminative idealist, denying that physical objects even exist.  I allow for this by using the word “any” in front of “physical world” in my definition.  (Saying, for example, that “any trespassers will be shot” does not imply that there are any trespassers.)  Similarly, naturalism as I define it is compatible with dualism, identity physicalism, and eliminative physicalism.  So there is symmetry, contrary to what Welty thinks.  My definition of “theism” does say that God creates “the” physical world, so I assume that a theist is by definition not an eliminative idealist and does not think that God has for all eternity had a physical body.  My apologies to anyone who actually takes seriously those two options!
Welty’s second objection to my argument just changes my definition of atheism.  I admit my argument won’t work if you change my definitions!  By “atheism,” I just mean the denial of theism. Granted, this doesn’t fit perfectly with common usage, but it is one meaning of the term, and in any case that’s why I was careful to define my terms before stating my argument.
Welty’s third objection isn’t really developed but he’s in good company in making it.  Alvin Plantinga, for example, agrees with him.  Plantinga and Welty (and Locke and Leibniz) can’t imagine how the physical could produce the mental.  Yet somehow they can imagine the mental producing the physical.  I have a physicalist colleague who objected to my argument because he has the exact opposite intuition.  He can imagine the physical producing the mental (he sees or thinks he sees this happen in nature), but he can’t imagine how mere thinking could bring into existence a physical object (he never sees such magic happen in nature).  Of course, what we see happen in nature is irrelevant to the *intrinsic* probabilities of naturalism and supernaturalism.  If substance dualism is true, then I agree it’s hard to imagine how the mental could produce the physical or vice versa since (arguably) that seems to require bringing something into existence out of nothing.  If physicalism or idealism is true, then it’s easier to imagine either bringing about the other.  In either case, we have symmetry between naturalism and supernaturalism, which is all I need for my argument.