Friday, August 18, 2017

Sean Carroll's "The Big Picture" Reviewed:
Why "Poetic Naturalism" is an Oxymoron

The Standard Model*, from Wikimedia Commons (by Latham Boyle)


Scientism, the belief that science can explain everything about the world and ourselves, is a religion, although not formally expressed as such. When I call it a religion, I mean that it is founded on faith, a faith that its proponents say is not faith, but rationality, but which is in fact a faith that denies rational objections to scientism.

There are many scientists who write books justifying their faith that science  gives the only answer to the question, “how should we live?”   Whether they do this to gather people into the fold or just to make money is a question I can’t answer.

Some--I'm thinking of Richard Dawkins in particular--are so convinced of the righteousness of their belief and the evil of religious faith that they would prohibit the practice of religion.  Others--I'm thinking of Sean Carroll--take a more balanced view, conceding there may be legitimate reasons for belief in God, but those reasons aren't for them.  Carroll’s new book, “The Big Picture”, gives his account of a materialistic ethos that doesn’t need God.

I believe there are serious flaws in Carroll’s arguments used to justify his non-belief, particularly in the two foundation stones for his thesis:

  • Poetic Naturalism” is a philosophy that will enable one to lead a moral, satisfying life, one that doesn’t need God;
  • Bayesian probability analysis and abductive reasoning demonstrate that it is very unlikely that God exists. 

I will also argue against Carroll’s views on the Anthropic Coincidences, Mind and Free Will, and Morality.


Carroll defines “Poetic Naturalism” as follows:
“Naturalism claims that there is just one world, the natural world…’Poetic’ reminds us that there is more than one way of talking about the world.   We find it natural to use a vocabulary of ‘causes’ and ‘reasons why’ things happen, but these ideas aren’t part of  how nature works at its deepest levels. “
—Sean Carrol, “The Big Picture”, pp 3-4. 
Carroll goes on to say that phenomena that I put outside the purview of science—for example, love, morality, beauty—are “emergent”.   Let me explain this more fully:   often in science when descriptions at a molecular or atomic level become very complicated and collective phenomena are involved, it is easier to describe things in a semi-empirical way.   Thus, for viscous flow hydrodynamic equations are set up; or to analyze ferromagnetism a collective description, an Ising model, is used.

For example, when we say “water is wet”, we could (in principle) give a reductionist picture and explain what’s happening  in terms of the surface tension of water, and at a deeper level, by an analysis of intermolecular attractive forces.   In short, we very often use a different language to explain or describe what could ultimately be explained by fundamental laws of physics (down to the level of subatomic particles and field theory).**

I call that view—that it’s only a matter of what descriptive language is used—a copout, a “scientism of the gaps”.    This position is not one that can be easily defended.  Indeed, poetry itself,  the joint appeal to our sensibilities of Shakespeare, Shelley and Bob Dylan, is not to be parsed by science.
So, as my subtitle suggests: the term “poetic naturalism” is an oxymoron.  It does not really explain, it just evades fundamental questions.


Carroll uses a combination of abductive reasoning***, “Inference to the Best Explanation” (IBE), and Bayesian probability analysis to argue that it is very unlikely that God exists.   Here’s one such argument:
“We have two  competing propositions: one is that God exists, and that transcendental experiences represent…moments when we are close to divinity;  the other is naturalism, which would explain such experiences the same way it would explain dreams or hallucinations…To decide between them, we need to see which one coheres better with other things we  believe about the world."
—ibid, p.134

Clearly Carroll believes the second explanation is the best, i.e. naturalism.    Others (myself among them) would believe that transcendental experiences cohere better with the existence of God, as does everything else we believe about the world.

Before discussing how Carroll applies Bayesian probability analysis to support naturalism, I’d like to emphasize some general points (taken from William “Matt” Briggs’ [“Statistician to the Stars”] blog post and book).   First, all probability is conditional, depends on evidence; such evidence may be facts, or it may be beliefs, beliefs founded on facts or knowledge, or—dare I say it—on Revelation. It’s just a way of working backwards from evidence to infer a probability.  Second, probability is quantitative.  You assign numerical values to  probability based on the evidence;  otherwise, there’s no way to judge between probabilities based on different evidence.

One well-known example of Bayesian analysis is the Monte Hall three door problem.   I want to  emphasize that Bayesian analysis requires quantitation (even if it's just a best guess, and a definition of an appropriate population (or prior probability) to conform with updated information and evidence.   The Appendix gives an example of such reasoning.  This isn’t what Carroll does.

Carroll argues that if God existed, he would create a world that provided overwhelmingly conclusive evidence for his existence:
“Imagine a world in which miracles happened frequently, rather than rarely or not at all.   Imagine a world in which all of the religious traditions from around the globe independently  came up with the same doctrines and stories about God… Imagine a world in which religious texts consistently provided specific, true, nonintuitive pieces of scientific information…Imagine a world in which souls survived after death, and frequently visited and interacted with the world of the living.  Imagine a world that was free of random suffering…In any of these worlds, diligent seekers of true ontology would quite rightly take those aspects of reality as  evidence for God’s existence.  It follows, as the night the day, that the absence of these features is evidence in favor of atheism. [emphasis added]
ibid., pp. 147-148

This view is simplistic in the extreme. It  does NOT follow “as the night, the day”, that the absence of these features is conclusive evidence for atheism. Consider just the statement that Scriptures should contain “specific, true, nonintuitive pieces of scientific information”.  The Bible is certainly not a science text.  It’s about how and why we should live.  Would a shepherd on the Judean Hills have made any sense out of Maxwell’s equations, or even Newton’s law of gravitational attraction?   Carroll’s argument here simply begs the question, assumes the answer he wishes us to believe.

To say that “God should make it easy to believe” is to support a proposition that ignores theology and philosophy.
Jesus said unto him, “Thomas, because thou hast seen Me, thou hast believed. Blessed are they that have not seen and yet have believed.” --John 20:29 (KJV)

That quote says it all.   I’ve argued in a blog post that there are excellent reasons why God does NOT make it easy to believe.    And there have been hosts of books on the problem of evil, theodicy, that show it is not truly evidence against the existence of God.

Let’s now consider some particular topics in Carroll’s “The Big Picture” for which his analysis is deficient:  the Anthropic Coincidences, Mind and Free Will, and Morality.


The Anthropic Coincidences are a set of restrictions on physical laws, constants, and geo-astronomical features, fine-tuned, so to speak, to enable the development of carbon-based life.   As explained in the post linked above, a  probability cannot be assigned to this “fine-tuning”, but it does strongly suggest that some sort of designing intelligence set up a universe in which humans could exist.   To quote Fred Hoyle:
"A common sense interpretation of the facts suggests that a super-intellect has monkeyed with physics, as well as with chemistry and biology, and that there are no blind forces worth speaking about in nature.   The numbers one calculates from the facts seem to me so overwhelming as to put this conclusion almost beyond question."--   Fred Hoyle,  “The Universe: Past and Present Reflections.” Annual Review of Astronomy and Astrophysics: 20:16, 1982.

Carroll acknowledges the force of this argument:
“…fine-tuning is probably the most respectable argument for theism.”—Sean Carroll, “The Big Picture”,  p.303

Nevertheless, he says fine-tuning is not sufficient evidence for the existence of a designing intelligence.  He argues that the universe is what it is, we wouldn’t be here to speculate about the fine-tuning if the universe wasn’t there.  He also proposes that “eternal inflation” creates an infinity of universes, a “multiverse”, so that amongst this multitude of universes one or more will be fine-tuned as ours is.   Yet belief in a multiverse is as much an article of faith as belief in God.  Many eminent physicists (including Roger Penrose and  Paul Steinhardt) consider that inflation is not a  proven physical theory.

Following David Hume (his favorite philosopher?), Carroll says that talk about causation is empty and fallacious;  we can only describe and give correlations, not give causes for the way things are.  Consequently we can’t say that the universe was purposely designed for anything.  There was no cause for the universe and its fine-tuning doesn’t need an explanation. Thomas Nagel has a fine response to this sort of argument:
"One doesn't show that something doesn't require explanation by pointing out that it is a condition of one's existence. If I ask for an explanation of the fact that the air pressure in the transcontinental jet is close to that at sea level, it is no answer to point out that if it weren't, I'd be dead.”— Thomas Nagel, Mind and Cosmos.

It’s worth pointing out that Nagel is an atheist, not a theist, but believes that the universe is indeed purpose-driven.


Books could be (and have been) written about the problem of mind and soul.   Rather than giving a full discussion and rebuttal of Carroll’s views on these issues, I’m going to cite some quotes and then, very briefly, argue against them.
“Under naturalism, there isn’t that much difference between a human being and a robot.  We are all just complicated collections of matter moving as patterns, obeying impersonal laws of physics…Wants and purposes and desires are the kinds of things that develop naturally along the way.”—Sean Carroll, “The Big Picture, p. 295
“If the world is purely physical, then what we mean by ‘understanding’****  is a way of talking about a particular kind of correlation between information located in one system and conditions in the external world.” ibid, p.348
“Consciousness isn’t an illusion, but it doesn’t point to any departure from the laws of physics as we currently understand them. [emphasis added].  ibid, p. 351
“One popular definition of free will is ‘the ability to have acted differently’.  In a world governed by impersonal laws, one can argue that there is no such ability.” ibid, pp. 380-381

I’ll not respond specifically to any one of these, but will only say that were I to believe them, I could see no reason for living.   I’ll add that there are philosophers and scientists who disagree strongly with each of these assertions, especially, 3 and 4.

Given that Carroll doesn’t believe in Free Will (or to put it more specifically, says that it’s only a way of talking about how we conduct our affairs), what does he say about morality?    How can there be ethical standards or moral values if we are not free to make decisions about our conduct, if they are predetermined by physical laws?

Let’s see what Carroll says about this; first, he acknowledges that without God there is no absolute moral standard:
“As Abraham learned, having an absolute moral standard such as God can be extraordinarily challenging.   But without God, there is no such standard [emphasis added] and that is challenging in its own way …Nature alone is no help. as we can’t extract ought from is;  the universe doesn’t pass moral judgments.”   ibid, p. 495

Then, according to Carroll, morality must be a personal construction:
“We have no objective guidance on how to distinguish right from wrong: not from God, not from nature, not from the pure force of reason itself…Morality exists only insofar as we make it so, and other people might not pass judgments in the same way we do.”  ibid, p.412.
“Poetic Naturalism refuses to offer us the consolation of moral certainty …How you should act depends on who you are. [emphasis added]”  ibid, p. 415.

So, that’s the problem, and I don’t believe Carroll offers a solution, other than that of the doctor in Camus’ “The Plague”:
“‘ What on earth prompted you to take a hand in this?’
‘I don't know. My… my code of morals, perhaps.’
‘Your code of morals. What code, if I may ask?’
‘Comprehension.’ “  —
Albert Camus, The Plague


There it is.   Poetic naturalism offers no support for a moral standard, and indeed, for any value system.   There is no reason we should take a system based (presumably) on Bayesian probability analysis and abductive reasoning to understand the world, other than that of the doctor in “The Plague”—it’s comprehensible.  

And here I think is where Carroll falls in to the honey-trap of scientism—that which can be explained in a scientific, naturalistic mode is that which is to be believed, and nothing else.   There is not a logical reason to follow this;  in fact, at the very beginning of “The Big Picture” Carroll emphasizes that science has nothing to say about the supernatural.  

So, I say Carroll’s “The Big Picture” is not that big.   It leaves out much of what is important and real for many of us.  But even so, reading his book, one gets the impression that Carroll is a thoughtful, learned, humane person.    I wish him well and hope he finds a belief system other than “Poetic Naturalism”.


*This illustration is used to acknowledge Carroll’s belief that the Standard Model for particle physics is the epitome of scientific knowledge, and that, in principle, all that needs be known about the world should conform to that model.  I’ve discussed the Standard Model in a post, God, Symmetry and Beauty: the Standard Model and the Higgs Boson.   I’ll agree that the Standard Model is one of the great intellectual achievements of modern physics, but as many physicists point out, it is not without problems and deficiencies.

**Or could do so if we had the knowledge, time and inclination for the more fundamental explanation.

***I’ve discussed modes of rational inquiry, including abductive reasoning, in a post, “Why do we believe…”.

****Carroll  is arguing here against John Searle’s “Chinese Room” analogy, a parable designed to show that computers can’t be self-aware.


ere’s an example using diagnostic tests. Suppose you visit a central Asian country, and after you’ve returned, are concerned about having contracted a parasitic disease, D, from having eaten a certain fish. There’s a diagnostic test T that’s good for detection of the disease, D: 99% sensitivity (i.e. the probability you actually have the disease D if you test positive is 0.99) and 90% specificity (the probability you don’t have the disease D if you test negative is 0.90). The prevalence of the disease D (proportion of people who have the disease in a selected population) is 0.1% in the general population. (Note: I’m picking numbers out of the hat in order to give a numerically simple example.)

You take the test and find that you have a positive result; should you be worried? Let’s consider 100,000 people in the general population.

  • The number of people out of a random sample of 100,000 with the disease D is 0.001 x 100,000 (prevalence times population size) or 100. 
  • Then, the number of people who don’t have the disease is 100,000-100 = 99,900. 
  • The number of people who have the disease and test positive is 100 x 0.99 = 99. 
  • The number of people who don’t have the disease and test negative is 99,900x0.90 = 89,910. 
  • Then the number who DON”T have the disease, but still test positive is 99,900-89,910=9990. 
  • The total number who test positive is then 99 +9990= 10,089. 
  • The probability that you have the disease is the ratio:                           number who test positive and have the disease / number who test positive = 99/10,089 =.0098 or about 1%.
--So, not to worry.

Now let’s change the population and include the fact that you’ve visited this Asian country. This is updating the evidence. For this population (people who’ve visited the country recently), the prevalence of the disease is 1% (or 0.01 in probability). Using the same type of analysis as above you can figure that in this case, the probability that you have the disease, having tested positive for it, is 990/10,890 or about 9%.

Let’s narrow the population some more, (update evidence further) and stipulate that only people who have visited the country AND eaten the certain fish will be taken as the population. In this case the prevalence of the parasitic disease is 50%. Doing the same type of analysis you would find that the probability of having the disease, having tested positive, is 49,500/54,500 = 0.908 or 91%.

Now the point of all this arithmetical fol-de-rol is to show first, that a probability analysis must be quantitative, and second, that updated information is used to specify a sampling population, or the prior probability.

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