Sean Carroll is a theoretical physicist at Caltech, a science popularizer and sometime atheist advocate. Like other science popularizers, such as Carl Sagan, Stephen Hawking, Lawrence Krauss and most obviously, Richard Dawkins, Carroll injects his atheist and materialist conclusions into his science writing, creating the impression that science implies atheism and materialism. A few decades of these voices representing the scientific community in popular media has contributed greatly to the impression that science and religion must be in conflict. Please take a look at my article on the alleged conflict between science and religion for a full consideration of that objection to Christianity. In his 2016 book, The Big Picture, Carroll makes his materialist conclusions somewhat more prominent and explicitly ventures into the realm of philosophy. Carroll’s style stands in stark contrast to the more aggressive styles of Richard Dawkins and Lawrence Krauss. He describes his views in a humble and self-deprecating way and clearly makes an attempt not to be insulting to religious people. The difference of attitude should not be glossed over and it is certainly a virtue of his work and his person. However, his metaphysical and epistemic views are very similar to what is defended by the New Atheists ( namely, a form of logical positivism).
Carroll seems to assume from the outset that science has the answer to the question of metaphysics, to the question of what is real. He doesn’t defend that assumption although almost everything he says about “reality” and “ontology” in the first two chapters presupposes that claim. This is significant, because as a naturalist who thinks his metaphysical conclusions are derived straight from the hallowed halls of the Royal Society or the National Academy of Sciences, his central metaphysical claim is the idea that science is metaphysics or that science holds the key to metaphysics. He may think perhaps this is self-evident, but there are many reasons to think that science does not and will never provide a holistic picture of reality. I will first address the more general notion assumed by Carroll that the scientific method is the basis of metaphysics and epistemology ( i.e. scientism). I will then address his description of his metaphysics more directly. Skip down to the sub-heading “Sean Carroll’s metaphysics” if you already know that scientism is irrational.
Science is not Omniscient
The most obvious reason why science cannot give us a holistic picture of reality is that science is methodologically circumscribed. Science, at least how it is practiced today, cannot give us a holistic picture of the universe because it methodologically precludes anything that is not material and impersonal and so it methodologically precludes explaining anything with reference to personal agents. So to say that God or the supernatural or the mind or the first-person experience of consciousness does not exist based on the scientific picture of what exists is a lot like having a psychological study that only has prison inmates in the sample and then concluding that well-adjusted people do not exist. Science has always limited itself to the study of particular phenomena.To conclude based on its study that other phenomena does not exist is viciously circular and illogical.
Scientism is Self-Refuting
Moreover, the idea that the scientific method is the only way to gain knowledge ironically refutes the scientific method and so itself. If the scientific method is the only way to gain knowledge, then the only way to gain knowledge is to verify something empirically. If something does not count as knowledge because it cannot be verified empirically, then the scientific method itself is not knowledge because it was not verified empirically (and it cannot be mathematically proven either). Even if you could somehow verify the scientific method empirically or mathematically, you would then have used the scientific method to verify the scientific method, which is circular and illogical. In other words, it is logically impossible or incoherent for the scientific method to be verified by the scientific method. If the scientific method itself is not valid then all the results of the scientific method does not count as knowledge either. Scientism (the epistemological claim that only science gives us knowledge) is self-refuting.
The Question of Existence
More than this, there are several aspects of the world which, by their very nature, are not amenable to explanation in terms of impersonal mechanisms. See my article about the God of the Gaps objection for more on this. One, the fact of existence or being, the existence of the universe as a whole, cannot be explained scientifically because it cannot be explained naturalistically. If you are looking for the “why” of the universe and not things in the universe, then it is illogical to explain the universe with reference to the universe. In order to explain something that is contingent (could have failed to exist), you always have to appeal to something outside of it. Nor can you say, as Carroll suggests later on, that you can ask “why” for anything in the universe but not for the universe itself, because that is an arbitrary stopping point conveniently coinciding with naturalism’s metaphysical weakness. If the universe could have failed to exist, there must be an explanation for its existence. If we deny this for any other thing in existence, anybody recognizes the absurdity, which means you need very good reason for denying it in the case of the universe. If that principle applies to the existence of anything else, then it is arbitrary to simply declare that it does not apply to the universe as a whole. And this point is made stronger by the fact that we know the universe came into being. Carroll suggests that we can deny that the universe as a whole requires explanation because we don’t know that there is anything outside itself to explain it. There is not necessarily any wider context. (This isn’t all that Carroll says about the Principle of Sufficient Reason and his main point is that the Principle is an empirical principle that has been extrapolated and so should not be universalized to apply to everything. I will address this more fully in a future post.)
But this doesn’t make sense as a response. To say that something doesn’t require explanation because we don’t know the explanation is irrational. Clearly, before we explained something we don’t know what explained it, and we didn’t know that there existed something that could explain it, but the fact of not knowing what explains something doesn’t affect whether or not it requires explanation. If we know that something requires an explanation and we don’t know if there is anything beyond the universe, then this implies that there is something beyond the universe. And we cannot deny the legitimacy of that rational intuition because similar rational intuitions underly the basics of mathematics and logic ( like modus ponens, modus tollens, the law of non-contradiction, the law of the excluded middle), which are used to answer questions of cosmology and in every single other scientific theory.
The Principle of Sufficient Reason is a rational intuition of the same kind, because to suggest that something that is contingent ( could have failed to exist) does not require an explanation is to affirm a logical contradiction. If something could have failed to exist then it must depend on something else for its existence. If you deny that a contingent thing requires explanation then you are affirming both that it depends on something else for its existence and that it does not, which is a contradiction. By saying it is contingent, you are affirming that it depends on something else for its existence and by denying that it requires explanation you are affirming that that something that it depends on for its existence does not really exist. You cannot selectively choose which rational intuitions to listen to and if one rational intuition does not apply to the cosmological scale of existence (because our brains didn’t evolve for the very large or the very small) then the others don’t either, which means the entire field of cosmology is invalid. It is interesting how atheists exempt the minds of scientists from what they believe are the effects of evolution. Were the brains of scientists not also evolved for the world of medium-sized objects? This shows how naturalism is anti-scientific because it tends strongly to saying that things are simply meaningless and don’t have or require explanation, similar to the ancient Pyrrhonian skeptics who believed that the universe couldn’t be understood and so there was no reason to bother studying it. Atheists deny the purposiveness of nature, which is the justifying reason for scientific endeavor. If things in nature do not have a reason, why would you try to find out what the reason for things in nature are? This contrasts with the monotheistic worldview which says there is a Mind who created nature and assigned each thing its purpose, which gives a justifying reason to scientific endeavor.
Consciousness, Morality, and Existential Purpose
Mind will also not be explained naturalistically, because in assigning an impersonal explanation to mind you have eliminated what you sought to explain. Precisely the thing to explained is the first-person experience of consciousness, which assigns personal explanations, for example, “I boiled water because I wanted coffee.” If you explain consciousness entirely through impersonal mechanisms then you eliminate the personal nature of consciousness. If your explanation eliminates what you are seeking to explain then you have obviously failed to explain it. Since science, as practiced today, is only allowed to explain through impersonal mechanisms and methodologically precludes explaining anything personally, it will by definition never explain the personal nature of consciousness. And to deny the contents of consciousness is self-refuting because rationality and reasoning, including all scientific endeavor, depend on it. Morality cannot be explained by science and also by definition never will be. Science can tell us perhaps why certain societies regarded things as moral and immoral, but it cannot provide a basis for objective morality itself. Science can give us the “is” but not the “ought”. It can tell us why we regard things as moral but not why things really are moral or immoral, which means that scientism implies moral nihilism. As already discussed, science itself cannot be justified or explained by science. Finally, our intuition that life is meaningful or should be meaningful cannot be explained by science, or cannot give a justifying reason for that meaning. A worldview structured purely by naturalism undermines rather than supports the intuition that human life is meaningful and significant.
Science Utopianism is Groundless
Like other naturalists and atheist science popularizers, Carroll has a utopian and unjustified faith that science is omniscient, or will eventually explain everything (worth explaining), which can be seen in the following quote: “We will ultimately understand the world as a single, unified reality, not caused or sustained or influenced by anything outside itself…” Based on what does Carroll believe this? He doesn’t say. He may believe this because science has shown a great deal of success in explaining things in the past. As I explain here, the past success of science is a very poor basis on which to believe that it is omniscient. As any stock broker or historian will tell you, what happened in the past is often not a good indication of what will happen in the future. This argument is also a double-edged sword, because the history of science also shows us a number of failures of science – false ideas that were eventually abandoned, but that held sway for a long time. So if you can argue from the successes of science you can also argue from its failures and you can argue that whatever is believed today as scientific orthodoxy may just as easily be abandoned tomorrow, no matter how fervently the scientific establishment defends it now.
Sean Carroll’s Metaphysics
So let’s take a closer look at what Carroll thinks about metaphysics or ontology:
“The last five hundred or so years of human intellectual progress have completely upended how we think about the world at a fundamental level. Our everyday experience suggests that there are large numbers of truly different kinds of stuff out there. People, spiders, rocks, oceans, tables, fire, air, stars – these all seem dramatically different from one another deserving of independent entries in our list of the basic ingredients of reality. Our “folk ontology” is pluralistic, full of myriad distinct categories. And that’s not even counting notions that seem more abstract but are arguably equally “real,” from numbers to our goals and dreams to our principles of right and wrong.” Later Carroll concludes: “Every object you have ever seen or bumped into in your life is made of just those three particles. We’re left with a very different view of reality from where we started. At a fundamental level, there aren’t separate “living things” and “nonliving things,” “things here on Earth” and “things up in the sky,” “matter” and “spirit.” There is just the basic stuff of reality, appearing to us in many different forms.”
Matter is more real than form?
There are a couple of things we can say here. Carroll assumes without argument that the matter making up the many different things on our planet is most fundamental thing in reality. But why should we believe that? Why is the fact that all things are made up of particular particles mean that those particles are more fundamental, more real than the things that those particles make up? Why pick the smallest divisions of matter to be the center point of your ontology? Wouldn’t it be a bit strange to take apart your television and say that the smallest component parts of your TV are more real than the TV itself? The forms into which those basic particles are made is just as “fundamental” as the particles themselves. Carroll is not entirely clear, but it definitely seems as though he’s claiming that the “folk ontology” of there existing many different things is false because we know that all of these things are only made of a few different types of very small particles. It could be that he means that the world of “different things” is “less” real than the world of particles. But several times it seems as though he is claiming that the world of “medium-sized objects” is not real – only the particles they are made of are real. Clearly, this is false. This is to think that the only thing that is real, or what is most real, about something is the material from which it is made, but just as real and as significant, is the form the matter takes. Think of how irrational it is to say that because one lump of wood is the same weight and contains the same particles as another lump of wood, that therefore they are exactly the same things, even though the one is shaped as a small tree and the other as a dining room table. The fact that the one is a dining room table and the other is a tree is just as real as the matter from which each is made. To believe otherwise is to involve yourself in absurdity. This is to believe there is no real or fundamental difference between a human being and a similar-sized rock just because both are made of the same fundamental particles.
If the smallest divisions of matter are what is real about something, then the differences on any other level of analysis are not real, resulting in the absurdity just described. It may seem uncharitable of me to interpret Carroll this way, but this view is made clearer later on when he considers the “ship of Theseus.” The ship of Theseus is a philosophical problem that is meant to make us think about the nature of identity. The ship of Theseus is kept in preservation, but through multiple renovations over time every plank in the ship is ultimately replaced with a different plank. Is it still the ship of Theseus or is it now a different ship? Carroll answers “We would now say that Theseus’s ship is made of atoms…exactly the same kinds of particles that make up every other ship, or for that matter make up you and me. There isn’t some primordial “shipness” of which Theseus’s is one particular example; there are simply arrangements of atoms, gradually changing over time. That doesn’t mean we can’t talk about ships just because we understand that they are collections of atoms. It would be horrendously inconvenient if, anytime someone asked us a question about something happening in the world, we limited our allowable responses to a listing of a huge set of atoms and how they were arranged…” Here again is the suggestion that because things are made of the same particles, that somehow makes the macroscopic properties and differences between them irrelevant or inconsequential to the point that talking about those macroscopic properties is just a matter of convenience.
Carroll concludes: “It just means that the notion of a ship is a derived category in our ontology, not a fundamental one. It is a useful way of talking about certain subsets of the basic stuff of the universe. We invent the concept of a ship because it is useful to us, not because it’s already there at the deepest level of reality.” Carroll seems to be somewhat inconsistent here. He seems to admit that the arrangements of the atoms is as ontologically significant as the presence of the atoms themselves as universal matter makers, but that would mean that the existence of the ship is just as ontologically significant as the existence of the atoms that make it up. He seems to deny that elsewhere. However, Carroll’s main claim here is that matter is more real or more fundamental than form, but he never defends this idea.
Firstly, we should say that it is not clear what it means for something to be less or more real than something else. As far as I can see, this doesn’t make sense. Something is either real or it is not. It either exists or it does not. There is no such thing as something half-existing or existing three-quarters of the way.
Second, as we’ve already touched on, the form that matter takes is just as fundamental and just as real as the matter because formless matter is something which doesn’t make sense and that does not actually exist anywhere. Matter always has form. Even when it’s just a blob of mud, it still has a form. What would formless matter look like? It’s a contradiction in terms because for matter to exist at all, it must take some sort of form. To talk of “matter” or the fundamental particles of matter apart from the forms it takes in the real world is a fictional abstraction, not a reality, because it doesn’t actually exist anywhere. The significance of form is why Aristotle distinguished between different kinds of causes: the formal cause, the material cause, the efficient cause and the final cause. Science has not discovered anything which make these causes less relevant, as Carroll may think. The formal cause of thing is just as ontologically significant as its material cause, because otherwise, as we saw, you would be forced into the conclusion that an object that has the same number of atoms as a human being is the same thing as that human being. This is clearly absurd but that is what is implied by thinking that only the matter that a thing is made up of is ontologically significant. In summary, to say that matter is more real than form doesn’t make sense because the things the matter is made up of is clearly just as real as the matter itself, because matter cannot and does not exist without form, and thirdly, it doesn’t make sense to say that something is more or less real than something else. It is either real or it is not.
A Radical Eliminative Materialism?
Sometimes Carroll does seem to go further than saying that ships are less real than the atoms that make them up and says instead that the ship does not really exist, only the atoms that make it up. This comes through when he for example says that the concept of ships is invented because it is useful to us. If we invented it then it is not real and not an objective part of the universe. But this again does not make sense. To bring out the irrationality of this, let’s go to a “medium-sized object” that is actually natural and not made by human beings. Do we “invent” the concept of trees because they are useful to us? No the tree exists. It has branches and leaves. It has objective properties in its macroscopic form which can be and have been studied and classified by scientists. Those classifications are not invented. They are based on objective properties of the trees. Those are its properties and those properties would exist exactly as they are regardless of what we call them and regardless if anyone were around to observe or think about them. Those properties are just as real as the smallest division of matter it is made of. Why are the macro-properties less significant or less real than the smallest parts into which any particular thing can be divided? Just because there is smaller stuff from which it is made does not mean that its larger properties that appear to us are ontologically less significant. The logical fallacy that Carroll is committing here is called the fallacy of composition. Just because something is made up of atoms doesn’t mean that atoms are the most significant thing about it. It is not just “convenient” or “useful” to talk about the concepts of ships and human beings, because this results in the absurdity that the only difference between a human being and a ship is a “way of talking about things” or a matter of convenience. Is there no fundamental difference between a human being and ship? I would say the difference between ships and human beings are quite fundamental. Does it make sense to say that the “most real” thing about a car is the fact that it is made of metal? Yes the metal is real, but just as significant is what the metal forms. Think about how irrational it is to say that the most real thing about a car is the smallest parts it can be divided up into before it is assembled by the factory machines. The car is just as real as the parts it is made up of. It is not merely “useful” to talk about the car. It is not just a “way of talking” about the basic parts of a car. Another problem with Carroll’s line of thinking is that it results in an infinite regress. The atom is also made of matter. There are even smaller components and smaller divisions, and there will be smaller divisions of those smaller divisions and so on and so on. To say that reality is defined by the smallest parts into which something can be divided is a dead end.
A Lack of Clarity and Undefended Presuppositions
One of my main problems with Carroll’s explanation of his metaphysics here is that he is very unclear. For example, one concept that Carroll uses over and over again is the idea that this or that is “fundamental” to reality and this other thing is “derived.” But what does it mean for something to be fundamental in reality? Carroll only defines this once as far as I can see and it isn’t a good definition at all:”…by “fundamental” we mean “playing an essential role in our deepest, most comprehensive picture of reality.”7 This definition seems circular, because Carroll seems to have just switched out “fundamental” for “deepest”. The question then just becomes what do you mean by the “deepest” reality? What does it mean for reality to be deep? Basically, Carroll discusses ontology but he does not defend his own ontology and epistemology which seems to boil down to two fundamental axioms: knowledge is what can be known through science and reality is purely the matter that things are made up of. That it seems is what he means by reality at the “deepest” level. But what he thinks is just reality at the deepest level is just matter at the deepest level and he has not given us a reason to identify one idea with the other. That is to say, he has not told us why matter at its simplest is the same thing as reality at its simplest. That is a significant oversight because it is the main claim of materialism. So, if a materialist fails to defend his main claim, he has not given us any reason to accept his metaphysics.
Sometimes Carroll seems to advocate a simple and radical eliminative materialism, in which the things that appear to us are just illusions produced as a by-product of impersonal mechanisms at the smallest level of analysis. Other times, he seems to say that there is more. For example, I’ve already quoted him saying that it is merely useful and convenient to talk about ships rather than atoms, and that the concepts like ships are invented, seeming to suggest that those categories are not real ( which is eliminative materialism). But then he also says that these are “derived” categories, not fundamental, seeming to suggest that they are real but not as real as the “fundamental” categories. He contrasts his own view with eliminative materialism in the following way: “A poetic naturalist will agree that both Captain Kirk and the Ship of Theseus are simply ways of talking about certain collections of atoms stretching through space and time. The difference is that an eliminativist will say “and therefore they are just illusions,” while the poetic naturalist says “but they are no less real for all of that.”” It seems like he is suggesting that the eliminativist is actually correct, but we can speak about minds, intentions, and our different concepts as long as we understand that they are just metaphors or figures of speech to signify the movements of atoms. As he says earlier: “At the moment, the dominant image of the world remains one in which human life is cosmically special and significant, something more than mere matter in motion.”9 This implies that the dominant image is wrong and that reality is just matter in motion. Carroll calls this the “scientific image” of the world. He doesn’t explain why what is studied in physics should be the only things that are considered real. There is nothing scientists have discovered that suggests that matter is the only reality or that the smallest known divisions of matter are the most real. These are ontological claims that need to be defended. Carroll doesn’t give the scientific discoveries or philosophical arguments that he believes support these claims. He simply assumes them.
Carroll often uses the phrase “way of talking about things” to describe the ideas of goodness, truth, beauty and other concepts of the macroscopic world that do not involve a description of the movement of atoms. He never really explains what he means by this, which means we are left to guess at its meaning. Often when we say that this or that is a “way of talking” about something we mean that there are different ways of saying the same thing. That is not what we have with materialism and the concepts it seems to eliminate: personhood, beauty, goodness etc. To say that goodness, truth, intention, and so on are just a way of talking about things can be taken to mean that talking about truth and goodness and talking about atoms or chemical reactions in the brain are really the same thing. But if that is what he is saying then it is just a different way of describing eliminative materialism. It is very difficult to reconcile the language we use when we talk about our mental events and our first-person experience of consciousness and the language we use to describe brain events. Precisely the problem with eliminative materialism is that the brain events and mental events are not the same thing and thinking they are the same thing results in a number of absurdities. For one, mental events have propositional content, but neurochemical processes do not. Our experience through our minds are real and it is not or not just a chemical reaction in the brain. To deny that this first-person experience of consciousness is real is to deny that the contents of this experience of consciousness is real, which includes our reasoning by which we do science. Reasoning is also something we do in our conscious minds. Eliminative materialism means that mental causation cannot exist, which means that rationality cannot happen. That is why eliminative materialism is self-refuting. For more on why eliminative materialism is wrong, see here and here. Apart from the mind, committing yourself to the idea that only the atoms that make up a thing are the reality of that thing is to believe something that is irrational. Macroscopic things very clearly have their own properties and natures which exist apart from our conceptualization of them.
Perhaps he means that “ways of talking about things” are concepts that describe a different facet of the same thing. That doesn’t seem to be what he means because he clearly thinks the one facet is more real than the other facet. And, in some instances, it seems like he thinks that the one facet is not real at all, is just an appearance, like a phantom in the corner of your eye or a fearful mind over-interpreting a lamp stand to look like an intruder in the night. In other words, the only thing that’s real is your perception or your apprehension of them, not that there is anything real that corresponds to your perception.
To summarize, Carroll doesn’t defend his central (radical) metaphysical claims and simply claims without argument that they are supported by the scientific picture of reality. He doesn’t tell us which scientific discoveries shows that his metaphysics is true and doesn’t give us a philosophical defense of materialism and scientism. Finally, it is unclear what his version of naturalism amounts to. He is inconsistent or ambiguous in describing it. Some of what he says seems to suggest a radical eliminative materialism ( like saying that concepts of the macroscopic world are merely useful inventions for the sake of convenience). Other things he says seems to suggest a softer materialism that recognizes some reality in concepts that do not include atoms and electrons. He is not clear about what it means for something to be more and less real than something else and as I’ve argued, this doesn’t make sense. Something is either real or it isn’t; it either exists or it does not. Something cannot half-exist.
 Carroll, Sean, The Big Picture, (New York: Dutton, 2016) p. 45
 Ibid., 13
 Ibid., 11
 Ibid., 12
 Ibid., 17
 Ibid., 17
 Ibid., 14