New Book on God, Physics, and the Philosophy of Science

Koperski, Jeffrey. The Physics of Theism: God, Physics, and the Philosophy of Science (Blackwell, 2015). The book is due out next month. Here's the blurb:

The Physics of Theism provides a timely, critical analysis of the ways in which physics intertwines with religion. Koperski brings clarity to a range of arguments including the fine-tuning argument, naturalism, the laws of nature, and the controversy over Intelligent Design.
  • A single author text providing unprecedented scope and depth of analysis of key issues within the Philosophy of Religion and the Philosophy of Science
  • Critically analyses the ways in which physics is brought into play in matters of religion
  • Self-contained chapters allow readers to directly access specific areas of interest
  • The area is one of considerable interest, and this book is a timely and well-conceived contribution to these debates
  • Written by an accomplished scholar working in the philosophy of physics in a style that renders complex arguments accessible
Further details here.

Swinburne Conference Videos

Sorry, I've been meaning to put this up for a while, but it got set aside due to work. Here they are. I haven't seen them all yet, but the one's I've seen are terrific.

Note the comment under each video: "In late 2014 or early 2015, there will be an opportunity for the speaker to respond to selected comments and questions. Comments (which can be made in the box below) will be moderated and will not appear immediately."

Call for Abstracts: Theistic Ethics Workshop

CFA, Theistic Ethics Workshop

The organizers of the first annual Theistic Ethics Workshop encourage abstract submissions for our inaugural meeting at the Graylyn Conference Center ( on the campus of Wake Forest University. The workshop will be held on October 8-10, 2015, and details can be found here:

Authors of accepted abstracts will have all their expenses covered, including travel. This workshop is being supported by generous funding from the Thomas J. Lynch Funds of the Wake Forest University Philosophy Department. Please direct any questions to

Mark Murphy (Georgetown)
Christopher Tucker (William and Mary)
Christian Miller (Wake Forest University


Theism and Material Causality

Draft. Fair use laws apply.  Comments welcome!
1. Introduction
Call classical theism the view that there is a personal god who is omnipotent, omniscient, and morally perfect, and call the classical view of creation the view that consists in the following three theses: (i) God is wholly distinct from the natural world; (ii) God is the originating or sustaining cause of the natural world; and (iii) God created the natural world ex nihilo. Finally, call classical theismcvc any version of classical theism that includes the classical view of creation.[1] In this paper, I argue that the classical view of creation conflicts with our evidence that objects with an originating or sustaining cause require a material cause, and that since classical theismcvc includes the traditional doctrine of creation, classical theismcvc is called into serious doubt.
2. The Argument
The argument I’ll defend can be expressed as follows:
1. All concrete objects that have an originating or sustaining cause have a material cause of their existence.
2. If classical theismcvc is true, then the universe is a concrete object that has an originating or sustaining cause without a material cause of its existence.
3. Therefore, classical theismcvc is false.

The argument is valid[2]. What can be said on behalf of the premises? Premise 1 expresses a causal principle, which I’ll call the principle of material causality, or PMC for short.  PMC asserts that concrete objects have a material cause whenever they have an originating or sustaining cause.  Before I defend the premise, some preliminary remarks about terminology are in order. First, concrete object denotes at least the sorts of entities classically individuated by the category of Substance, and distinguishes them from those of other categories (e.g., property, relation, event, trope, etc.). Examples include atoms, stars, rocks, planets, trees, animals, and people. They are thus distinguished from concrete entities in other categories (shapes, surfaces, events, and the like) and abstract objects (propositions, numbers, sets, and the like). 

The next two key terms are originating cause and sustaining cause. The former denotes an efficient cause of the temporal beginning of a thing’s existence[3], and the latter denotes an efficient cause of a thing’s continued existence. Thus, matches and lighter fluid are at least partial originating causes of a flame, and the oxygen that surrounds it is at least a partial sustaining cause of a flame.

Finally, material cause aims to capture (roughly) Aristotle’s notion of the term, and to individuate it from the other three distinguished by Aristotle, viz., formal, efficient, and final causes. By ‘material cause’, then, I mean ‘the things or stuff from which another thing is made’.  Thus, the material cause of a penny is the parcel of copper from which it was made, and the material causes of a water molecule are the hydrogen and oxygen atoms from which it was made.

Two points about PMC merit special emphasis. First, PMC is restricted to concrete objects as we’ve defined them. It is therefore neutral about whether entities in other categories require a material cause. Second, PMC restricts the requirement of a material cause further to just those concrete objects that have an originating or sustaining cause. It therefore allows for the possibility of concrete objects that lack a material cause, viz., those that lack an originating and sustaining cause. The premise thus allows that the universe may lack a material cause if it’s beginningless and also lacks a sustaining cause. It also allows that a universe with a beginning may lack a material cause, if it also lacks an originating and sustaining cause. An example of the latter sort of case might be a temporally finite, four-dimensional “block” universe. To sum up: PMC is neutral as to whether all concrete objects begin to exist, and to whether all concrete objects that begin to exist have a material cause. The causal premise only rules out concrete objects that have an originating or sustaining cause, but lack a material cause. 

Is PMC plausible?  It certainly seems so. Here we can prime our intuitions with a few thought experiments.[4] Thus, suppose we were told that a certain log cabin had the following special characteristic: it popped into existence out of nothing without any cause whatsoever. Most, I imagine – including most of those who have read their Hume -- would find such a claim strongly counterintuitive, if not absurd. But suppose instead we were told the cabin was special for another reason: a lumberjack created it without any materials whatsoever. I imagine most would likewise find such a claim absurd or strongly counterintuitive. A similar intuition obtains when we consider any other concrete object arising from an originating cause without a material cause. Perhaps such intuitions aren’t enough to demonstrate the impossibility of an originating cause without a material cause, but we ordinarily take such seemings to be at least defeasible, prima facie evidence for what can or cannot be the case. 

We have similar grounds for thinking that concrete objects that depend upon a sustaining cause have a material cause. Thus, the continued existence of a flame depends upon a sustaining cause for its continued existence. But here we find that the flame’s sustenance also crucially involves a material cause, viz., reacting gases and solids. Furthermore, our intuitions in support of the causal principle are triggered when we attempt to imagine the flame’s continued existence without the presence of reacting gases, solids or some other material cause. The intuition doesn’t diminish when we imagine the flame to be past-eternal. 

In addition, it doesn’t require a full-blown Aristotelian metaphysic to find the materials for a powerful argument for PMC in the apparent relationship between what actually exists and what merely has the potential to exist. Thus, the possibility of the origination or sustenance of an object requires the prior potential for its existence. But it seems that this potential must “reside” in some actually existing thing or stuff. Thus, the potential existence of a penny “resides” in a parcel of copper. By contrast, nothingness lacks the capacity or potential for becoming anything, since nothingness has no capacities or properties whatsoever. Prima facie, then, concrete objects can’t come into being from nothing, but only from other concrete things or stuff.

Finally, PMC enjoys abundant empirical support. For our uniform experience is such that whenever we find a concrete object with an originating or sustaining cause, we also find it to have a material cause.  Furthermore, there seem to be no clear counterexamples to PMC in our experience. What explains this? PMC is a simple hypothesis, which, if true, would best explain this data. Experience thus provides significant abductive support for PMC.

That leaves premise 2. Why should we accept it? Premise 2 follows from our partial stipulative definition of ‘classical theismcvc’.  It’s therefore an analytic truth. This causes no trouble for the argument’s significance, for the partial definition captures several theses that are prima facie essential to classical theism.  Such theses are among those that individuate theism from neighboring views about God, such as pantheism, panentheism, demiurgic theism, Berkeleyan idealism, and Spinozistic monism. They’re also among the theses about God that have been accepted by most prominent philosophers within the theistic tradition, including Augustine, Anselm, Aquinas, (and, more recently) William Alston, Alvin Plantinga, and Richard Swinburne. Indeed, it’s safe to say that most contemporary analytic philosophers of religion would consider them essential theses of any account of classical theism worthy of the name. I therefore think it’s safe to say that the stipulative truth of the premise won’t undermine its relevance for evaluating classical theism’s epistemic merits.

We’ve seen that the argument from material causality is valid, that premise 1 (i.e., PMC) enjoys strong prima facie justification, and that premise 2 is an analytic truth. It therefore looks as though the argument poses a formidable problem for classical theism.

How might the classical theist respond?  Premise 2 is non-negotiable, as we’ve seen that it’s an analytic truth. That leaves open only two types of response for the classical theist: a non-concessive response, which involves providing a defeater for premise 1, and a concessive response, which grants the soundness of the argument, but rejects classical theismcvc. In the rest of the paper, I’ll briefly consider both sorts of response.

3. Non-Concessive Responses
As mentioned above, a non-concessive response involves providing principled grounds for resisting premise 1. This requires principled grounds for thinking the principle of material causality is false or without adequate justification. I can think of three main ways in which one might attempt to do so, which I shall consider below.

First, one might appeal to God’s omnipotence as a way of defeating premise 1. The basic line of reasoning is as follows: If the god of classical theism exists, then God is omnipotent. But if so, then since omnipotence entails the ability to do anything that’s metaphysically possible, it follows that the god of classical theism has the ability to create concrete objects ex nihilo, without a material cause. However, this reply is inadequate. For the very point at issue is whether ex nihilo creation of concrete objects is metaphysically possible, and we’ve seen that there are at least prima facie grounds for thinking that it isn’t metaphysically possible. Bare appeal to God’s omnipotence in this context is therefore question-begging.

Another possible criticism of premise 1 is one heard from some in the field of quantum cosmology, viz., that there are plausible models of the origin of the universe according to which the universe arose from nothing. However, such claims don’t bear out as counterexamples upon further scrutiny. For upon closer inspection, what one finds instead are much weaker claims, e.g., that the universe arose from a random fluctuation in a quantum vacuum[5], or that it arose from a universe of zero radius, which subsequently tunneled through an energy barrier and inflated into the universe as we know it.[6] But a randomly fluctuating, energy-rich quantum vacuum is not nothing in any relevant sense. Nor is a zero-radius universe that tunnels through an energy barrier and then inflates the same thing as a universe that arises from nothing. As such, they’re not counterexamples to PMC as expressed in premise 1.

Finally, the theist might resist premise 1 by appeal to agent causal views of the self. Thus, they might argue that there are good reasons to think that (i) humans possess libertarian free will, that (ii) this is best explained on the assumption that the physical realm isn’t causally closed, that (iii) the agent can thus cause things via energy from “outside” the natural causal order[7], and that (iv) this is sufficient justification for the existence of genuine creation ex nihilo, in which case premise 1 is false. This reply won’t work, however. For even if (i)-(iii) could be adequately supported – contrary to the opinion of the majority of analytic philosophers[8] – the falsity of the causal closure of the physical wouldn’t require positing the creation of concrete objects ex nihilo. Rather, at most, it would require the transfer of pre-existing energy from the agent (who acts from “outside” of the natural causal order) to the physical realm.[9] 

4. Concessive Responses
If one finds the non-concessive responses implausible, one might finally turn to a concessive response; that is, one might accept a view of God that denies the classical view of creation. There are three basic versions of such a response, each one corresponding to a rejection of one of the three clauses of the classical view of creation as we have defined it. I will briefly consider each sort of response below.

The first type of concessive response is to reject thesis (i) of the classical view of creation as we’ve defined it, thereby denying that God is wholly distinct from the natural world. According to this sort of response, one allows that the world is either (a) identical to God, (b) made from the stuff of God’s being, (c) a mere feature or mode of God’s being, or (d) an idea in the mind of God. Unfortunately, options (a)-(c) come at the high cost of abandoning classical theism altogether, as embracing one of these options amounts to embracing something in the neighborhood of pantheism, panentheism, or Spinozistic monism, respectively. And while (d) is arguably a version of theism, it requires embracing something on the order of Berkeleyan idealism. It would take us too far afield to evaluate the case for such a view, but it’s enough for our purposes to note that few have found the case for Berkeleyan idealism persuasive, in which case it seems unlikely that many are likely to accept a concessive response of this sort.

The second type of concessive response is to reject thesis (ii) of the classical view of creation.  According to this sort of response, God may or may not be omnipotent[10], omniscient, and morally perfect. However, he doesn’t play the role of creator of the universe in any sense. Call this sort of view hands-off theism.

It seems antecedently unlikely that there will be many takers for hands-off theism. This is for at least two reasons.  First, hands-off theism looks epistemically unmotivated. For many standard lines of evidence for theism depend upon inferences from the natural world to God. Examples include design arguments from the fine-tuning of the universe to a cosmic designer, as well as cosmological arguments for a first cause, ground of being, and sufficient reason for the existence of contingent concrete reality. But the god of hands-off theism plays none of these roles with respect to the universe. As such, accepting hands-off theism commits one to rejecting many of the core arguments of natural theology.  It’s also arguable that it causes trouble for religious experience. For example, in his widely-influential account of the evidential force of religious experience, William Alston[11] grants that awareness of certain phenomena (e.g., religious diversity) can undercut a good deal of the epistemic force of religious experience, and thus that the justification of theistic belief requires further buttressing with the help of other evidence, such as cosmological and design arguments. But again, the hands-off theist is committed to rejecting many such buttressing-arguments as evidence for her belief.  Now perhaps an adequate case for hands-off theism can be made that doesn’t depend on these lines of evidence.  But for our purposes, it’s enough to note that the hands-off theist has their work cut out for them.

Second, the god of hands-off theism seems to be of much less religious significance than the God of classical theismcvc. For on such a view, God is not responsible for the existence and order of the natural world. He is therefore not the cosmic architect, first cause, or ground of being upon which all else depends, let alone Anselm’s greatest conceivable being. Rather, he exists as just one among the many uncreated concrete objects within the universe, having less creative and providential control than even Plato’s demiurge. On such a view, then, the grandeur, preeminence, and otherness of God are severely diminished. There is also a corresponding loss of the awe that comes from a sense of ultimate dependence upon a Creator. But perhaps most troubling for many theistic philosophers of religion today is the fact that such a God seems not to be the God of traditional Christian theism. For prima facie, the Christian God is described within several canonical scriptural texts as the creator and sustainer of all things.[12]

The final type of concessive response is to reject thesis (iii) of the classical view of creation. According to this sort of response, God plays the role of creator and designer. However, he did not create the world out of nothing, but rather from pre-existing materials. For obvious reasons, let’s call this sort of view demiurgic theism.  Now it seems that demiurgic theism is an improvement over hands-off theism in terms of epistemic motivation, since on such a view god plays at least a diminished role qua creator and designer of the universe, fashioning the universe out of primordial matter/stuff. Therefore, while standard cosmological arguments cannot be marshaled in support of demiurgic theism[13], perhaps an argument from design can be made on behalf of such a view, as well as (perhaps) religious experience and other sorts of evidence that don’t appeal to an inference from the sheer existence of the universe to God.

However, whatever the epistemic merits of demiurgic theism, many of the drawbacks of hands-off theism apply here as well with respect to religious significance. For as with the latter view, the god of demiurgic theism is not the preeminent first cause and ground of being for the fundamental stuff of the natural world; nor does he provide the sufficient reason for its existence. He is therefore not responsible for the existence of the natural world in the ultimate sense that is ascribed to the god of classical theismcvc. Rather, he exists alongside of it as another uncreated concrete object. Therefore, such a view entails a much weaker view of divine preeminence and uniqueness than what has been historically attributed to the God of classical theism. Finally, as with hands-off theism, such a God seems at odds with the God of traditional Christian theism.  For at least these reasons, then, it’s doubtful that many classical theists will be happy with this route to resisting the argument.

5. Conclusion
A powerful argument against classical theism can be constructed from two simple elements: (i) classical theism’s thesis of creation ex nihilo, and (ii) the well-supported principle of material causality. The prospects for the only non-concessive reply to the argument – rejecting the principle of material causality – look bleak. Furthermore, the concessive replies all leave the classical theist with a picture of God and creation that they’re likely to find costly and unattractive, such as pantheism, panentheism, Spinozistic monism, demiurgic theism, hands-off theism, and Berkeleyan idealism.  Little attention has been paid to the argument to date, but our brief exploration of it suggests that it’s worthy of serious investigation.

[1] Berkeleyan idealism arguably fails to satisfy clause (i) of the classical view of creation as defined here. As such, while it may count as a version of classical theism, it fails to count as a version of classical theismcvc.
[2] Let: ‘T’= ‘classical theismcvc is true’; ‘Ox’ =’x has an originating cause of its existence’; ‘Sx’=’x has a sustaining cause of its existence’; ‘Mx’=‘x has a material cause of its existence’; ‘Cx’=’x is a concrete object (or collection of such)’; and ‘u’=our universe. Then we have:

1. (x)[Cx & (Ox v Sx)] -> Mx                               Premise
2. T -> [Cu & ((Ou v Su) &  ~Mu)]                       Premise
3.         T                                                          Assumption for indirect proof
4.         [Cu & (Ou v Su)] & ~Mu                                     2,3 MP
5.         [Cu & (Ou v Su)] -> Mu                          1 Universal Quantifier Elimination
6.         ~Mu                                                     4 &E
7.         ~[Cu & (Ou v Su)]                                  5,6 MT
8.         Cu & (Ou v Su)                                      4 &E
9.         [Cu & (Ou v Su)] & ~[Cu & (Ou v Su)]       7,8 &I
10. ~T                                                             3-9 ~I

[3] Consider any arbitrary carving up of the stretch of time of a given object’s existence into equal intervals of finite, non-zero duration, and ordered according to the ‘earlier than’ relation. As I’m using the expression, an object has a temporal beginning of its existence just in case any such carving up includes an earliest temporal interval.
[4] The following illustration is inspired by the one found on p. 29 Wes Morriston’s paper, "Creation Ex Nihilo and the Big Bang”, Philo 5:1 (2002), pp. 23-33.
[5] See, for example, Krauss, Lawrence. A Universe From Nothing: Why There is Something Rather than Nothing (Atria, 2013).
[6] See, for example, Vilenkin, Alexander. Many Worlds in One: The Search for Other Universes (Hill and Wang, 2007).
[7] An argument in this vicinity is broached in (e.g.) Moreland, J.P. “Naturalism and Libertarian Agency”, Philosophy & Theology 10:2 (1997), 353-383.
[8] According to a recent poll (, only 13.7% of philosophers answered with “accepting or leaning toward libertarianism”. At least 71.3% of philosophers polled stated that they think we don’t have libertarian free will, with 59.1% answering with “accepting or leaning toward compatibilism”, and 12.2% answering with “accepting or leaning toward no free will” (14.9% answered with “accepting or leaning toward ‘other’”).
[9] On this point, see (e.g.) Moreland, Ibid; Larmer, Robert. “Mind-Body Interaction and the Conservation of Energy”, International Philosophical Quarterly 26 (1986), pp. 277-285.
[10] Perhaps one will object that a god of this sort cannot be omnipotent if he cannot create or sustain the natural world. However, there is a long and established tradition of theists who claim that there are lots of things that an omnipotent god cannot do (e.g., make a round square, change the past, act contrary to his nature, know future free acts, etc.).  One standard justification for such restrictions is to say that such things are metaphysically impossible, and that omnipotence doesn’t include the power to do what is metaphysically impossible. But the same sort of justification seems available here. For the hands-off theist can say that creating or sustaining the universe with out a material cause is metaphysically impossible, and thus his inability to create or sustain a universe ex nihilo doesn’t count against his omnipotence.
[11] See, especially, Alston’s magisterial Perceiving God (Cornell University Press, 1993).
[12] Examples include (i) John 1:1-3: “In the beginning was the Word, and the Word was with God, and the Word was God. He was with God in the beginning. Through him all things were made; without him nothing was made that has been made”; (ii) Romans 11:36: “For from him and through him and for him are all things. To him be the glory forever! Amen”; (iii) Colossians 1:16-18: “ For in him all things were created: things in heaven and on earth, visible and invisible, whether thrones or powers or rulers or authorities; all things have been created through him and for him. He is before all things, and in him all things hold together”; and (iv) 1 Corinthians 8:6: yet for us there is but one God, the Father, from whom all things came and for whom we live; and there is but one Lord, Jesus Christ, through whom all things came and through whom we live.” (All passages are from the NIV version of the New Testament)
[13] I suppose a cosmological argument for an unmoved mover is still a possibility, although few have found arguments of this sort convincing since at least the dawn of Newtonian physics. Perhaps, though, the argument can be revitalized.  We’ll see.

Quick Sketch of a Case Against Classical Theism

First Argument: The Argument from Horrors, Hiddenness, Revulsion, and Inhospitable Environment

1. We’d expect horrors, hiddenness, revulsion, and an inhospitable environment if naturalism were true.
2. We wouldn’t expect horrors, hiddenness, revulsion, and an inhospitable environment if theism were true.
3. If we’d expect this data if naturalism were true, but we wouldn’t if theism were true, then the data confirms naturalism vis-à-vis theism.
4. Therefore, horrors, hiddenness, revulsion, and an inhospitable environment confirms naturalism vis-à-vis theism. (1-3)

Why we’d expect this data on naturalism, but not on theism:
o Horror: Some people suffer to the point where their life is prima facie ruined (e.g., being raped, tortured, dismembered, and driven permanently insane). If God exists, we’d expect that God would allow a person to suffer horrifically only if doing so is required for their deepest good (viz., endless intimate fellowship, giving ever-increasing knowledge of God). But prima facie, God's allowing horrific suffering isn’t required for this deepest good. By contrast, we’d expect horrific suffering if naturalism is true. For on such a view, the universe is indifferent to our welfare. (cf. Schellenberg)

o Hiddenness: If God exists, then we’d expect that God would meet all the prerequisites for all those who would want a voluntary relationship with him. One of the prerequisites is to let others know (or reasonably believe), if they wish, that he exists. But this condition hasn’t been met: there are non-resistant non-believers. One might resist or reject this line of reasoning on the grounds that God might have some outweighing reasons for allowing non-resistant non-belief -- e.g., moral, spiritual, or intellectual development. However, none of these grounds explains the massively uneven distribution of theists and non-theists in the world. For we’d expect the causes of non-resistant non-belief to lead to a fairly even distribution of theists and non-theists. But this isn’t what we find. By contrast, we would expect to find such an uneven distribution if theism were false. (Cf. Schellenberg, Maitzen)

o Revulsion: If theism is true, then we’d expect our cognitive and affective faculties to be reliable, and thus to track the truth about aesthetic properties of the world. Now if theism is true, then God made the world, and it is good. Furthermore, given epistemic reliability, my aesthetic judgments about the repulsiveness of parts of the natural world are prima facie justified, in which case parts of the creation are prima facie repulsive (See this post for examples). But this conflicts with the hypothesis that it is good (at least aesthetically). By contrast, repulsive features of the world aren’t at all surprising on naturalism, since we wouldn’t expect it to aim at aesthetic goodness. (Me)

o Inhospitable environment: The Earth is filled with harmful and lethal flora and fauna. Such flora and fauna are often either undetectable, or look harmless upon first inspection. Theism makes this surprising, as the Earth is supposed to be our home, and not a Hunger Games scenario. By contrast, such a human-inhospitable environment is expected if naturalism is true and life’s history is governed by evolutionary factors. (Me)

Second Argument: The Argument from Material Causality (Me. A draft of the long version can be found here. Comments on the draft are welcome!)

  • Concrete object denotes at least the sorts of entities classically individuated by the category of Substance, and distinguishes them from those of other categories (e.g., property, relation, event, trope, etc.). Examples: atoms, stars, rocks, planets, trees, animals, and people. They are distinguished from concrete entities in other categories (shapes, surfaces, events, ideas, etc.) and abstract objects (propositions, numbers, sets, etc.) 
  • Material cause denotes the things or stuff out of which a new thing is made (e.g., the material cause of a penny is a sheet of copper). 
  • Classical theism denotes the view that there is a personal god who is omnipotent, omniscient, and morally perfect. 
  • The classical view of creation denotes the view that consists of the following three theses: (i) God is wholly distinct from the natural world: the world isn’t identical to God or made from the stuff of God’s being. Nor is it an idea in the mind of God or a mere feature or mode of God’s being. Rather, it’s a concrete object that exists in its own right (or an aggregate of such); (ii) God is the originating or sustaining cause of the natural world; and (iii) God created the natural world ex nihilo.
  • Call  classical theismcvc  any version of classical theism that includes the classical view of creation. 
The Argument:

1. All concrete objects that have an originating or sustaining cause have a material cause of their existence.
2. If classical theismcvc is true, then the universe is a concrete object that has an originating or sustaining cause without a material cause of its existence.
3. Therefore, classical theismcvc is false.

· Support for premise 1: (a) rational intuition; (b) the relationship between what is actual and what is possible; and (c) inference to the best explanation.

· Support for premise (2): It’s a conceptual truth. It follows from the definition of ‘classical theismcvc’.

Linford and Megill's New Paper on Two Underexplored Arguments Against Theism

Linford, Dan and Megill, Jason. "I dolatry, indifference, and the scientific study of religion: two new Humean arguments ", Relig...