Blogging Alex Rosenberg's The Atheist's Guide to Reality, Chapters 1 & 2

Our faculty and staff reading group is currently reading Rosenberg’s delightful book. I’m storing my thoughts as we go along here on the blog.

Preface, Chapters 1 & 2

Rosenberg’s snarkiness doesn’t relieve us of the duty to read him as charitably as possible, construing what he says in ways that make it true unless he forces us not to.

1. Rosenberg’s “scientism.” This can be interpreted charitably, so one might reasonably suspect that it’s true, or uncharitably, such that no one could seriously believe it. On an uncharitable interpretation, scientism is the view that the only justified beliefs are the well-confirmed theories of the sciences. This interpretation is uncharitable because it is rather obviously false. The scientist may well know, e.g., where he had lunch yesterday, yet this bit of mundane knowledge is not acquired by the procedures by means of which he confirms hypotheses. The charitable interpretation is that our only way to acquire knowledge is by way of science and the less well-disciplined empirical procedures of daily life, and of other disciplines, e.g., history, that are continuous with full-fledged scientific methods. On the traditional view that the reliability of scientific reasoning is due to its rigorous commitment to hypothetico-deductive methods, scientific reasoning differs from ordinary empirical reasoning in degree, not categorically. Knowledge comes by way of using our senses and critically reasoning about what we sense. On a traditional view, this is still not really true, since there is mathematical knowledge and it’s not empirical, but if we restrict the claim to how we can know contingent reality scientism so construed is not crazy and might well be true. Whether, with this exception, it’s true, depends on what we should say about evaluative judgments, whether we should regard them as on occasion knowledge, and whether we make them on grounds that are broadly empirical. My inclination is to say that Rosenberg’s scientism, so interpreted and qualified, is true.

One may, of course, agree with Rosenberg’s general claim about the source of human knowledge while disagreeing on what specific beliefs can be justified, among others the belief that this world the empirical methods most reliably deployed in the sciences is not all there is, but that there is a God who created it, loves it, and acts upon it and within it. Any knowledge we can reasonably claim to possess about this depends ultimately on the empirical evidence. One can believe that the empirical evidence is adequate for such beliefs without denying that it is never reasonable to believe what conflicts with the well-confirmed theories of the sciences. As a way of knowing science trumps the competition but this does not imply that all knowledge is scientific knowledge, narrowly conceived.

Rosenberg (elsewhere) says, “by now in the development of science, absence of evidence is prima facie good grounds for evidence of absence: this goes for God, and a great deal else.” As a Christian, I think evidence is present which is at least good enough for rational hope; whether it’s adequate for knowledge seems to me an exquisitely hard question to answer. (Perhaps this is not altogether bad news: knowledge is nice, but at least hope does not suffer from the complacency to which knowledge is vulnerable.) What seems to me bad faith on the part of Christians is to ignore the fact that the vast majority of religious beliefs are not rationally justified and certainly false, and that claims we make on behalf of our own beliefs need to be defended from the charge of special pleading.

2. Rosenberg’s “naturalism.” That the physical facts “fix all the facts” about this world is, I think, roughly true, so long as it’s taken as a claim about the nature of God’s creation. While this is consistent with both reductionism and the eliminative materialism that Rosenberg seems to favor, it entails neither. Most naturalistically-oriented philosophers reject both, but do hold that the physical facts fix the facts about this world; eliminativism, like reductionism, is a distinctly minority opinion.

Off hand, the thought experiment of a world that is a microphysical duplicate of our world being exactly similar to it doesn’t succeed completely as a way to express the physicalism Rosenberg endorses. That duplicate world contains many pieces of green paper that are indistinguishable from U.S. Federal Reserve notes, yet they are counterfeit, having originated not with the U.S. treasury, but with its duplicate. Or: it is true of the world that Sam Martin exists in it but this is false of the microphysical duplicate, though it does contain someone who is highly similar to Sam Martin and who calls himself by this name, because he is convinced that he is Sam Martin. Thi sort of tign aside, what Rosenberg wants to deny is that there are properties that are emergent in some strong and interesting sense, as if, say, there could be a microphysical duplicate of a human brain that is not conscious mind (a zombie). The naturalistic claim (or bet?) is that we already have the essentials of what’s needed to explain the mind and we await no discovery of some new stuff or force. Consider the analogous but uncontroversial claim that this is true for the explanation of biological life.

I find Rosenberg’s discussion of the possibility of ultimate explanations in the context of quantum mechanics rather obfuscating. On the standard interpretation, quantum mechanical events are the effects of causes, and are explainable by subsuming them under the QM causal laws. These laws are indeterministic, in that there is more than one physically possible effect of a given cause. The laws fix the probabilities but do not guarantee a particular effect. So we have a law like: If x, then prob(y) = .5 and prob(z) = .5. When x occurs followed by z, z does not “just happen;” it was the effect of a cause, x. What’s left unexplained is why in this instance it was z, rather than y, that occurred. This is the sense in which the QM event is “random” or a “matter of chance,” not that there is an uncaused event. If we have the quantum field, governed by the probabilistic laws of quantum mechanics, then (on the theory Rosenberg has in view) events similar to the Big Bang are occurring all the time and in a small number of improbable cases, inflation occurs and a universe like ours comes into being. So far as I can tell, nothing in this answers the question, “Why does this quantum field exist?” and “Why are the laws of QM what they are?” and nothing in it implies that these are ill-conceived questions.

A partial analogy: there’s a chunk of U238 on your desk and the laws of QM tell you, with extreme precision, the probability of a decaying nucleus emitting a gamma particle in the next 60 seconds. If it does, we know what caused it, but there’s no reason why the uranium emitted the particle during that span of time when it was no less possible, and perhaps no less probable, that it would not do so. But this does not imply that that particle hitting you had no cause, and it does not make it unreasonable to ask how this hunk of radioactive uranium wound up on your desk, or why the stuff has the half-life it has.

On the standard (Copenhagen) interpretation of QM as indeterministic it violates what was traditionally called the principle of sufficient reason, i.e., for whatever is true, there is always an explanation why it’s true. Perhaps the PSR is further violated because there is no explanation of the quantum field and its laws, but this does not follow from the fact that the laws are not deterministic. As Rosenberg goes on to say, it makes no sense to ask why you won the (truly random) lottery: someone had to win and your chances were as good as anyone else who bought the same number of tickets. But this truism does not imply that we cannot reasonably ask why the lottery was held, or why a given number of tickets were sold.

At this point traditional natural theology wants to step in, asserting that for all we know the multiverse exists, but contingently, so we can reasonably ask why it exists, and the basic laws of nature are true, but contingently, so we can reasonably ask why they are true. In Chapter 1 Rosenberg asserts that there is no story anyone can tell about why the basic laws are true. Assuming that by “a story” he means a teleological explanation, he’s denying that there could be an ultimate explanation of the physical universe in terms of purpose. In Chapter 2 he goes on to claim that there can be no ultimate explanation at all. It’s not altogether clear why he thinks he is entitled to rule either out a priori. To draw an obvious distinction: the fact that there is no purpose in nature does not imply that there is no purpose for nature. Maybe he helps himself to reasoning that goes:

(i) Scientific explanation subsumes what it explains under the laws of nature

(ii) The laws of nature do not explain themselves

Therefore: there can be no scientific explanation of the basic laws of nature.

(iii) But scientific explanations are the only genuine explanations

Therefore: There is no genuine explanation of the basic laws of nature.

The first two premises and the first conclusion are true, but why believe (iii)? Even if we grant—as I would—(a) that scientific reasoning is our most reliable way of attaining to knowledge of contingent reality, (b) that no philosophical/natural theological claim, e.g. that there is a necessary being which our contingent universe depends on for its existence, is as well-grounded as the well-confirmed theories of the natural sciences, and thus (c) that no such claims should be accepted if they contradict the products of science, it’s hard to see how this implies that no such philosophical/natural theological claim can be rationally justified. Maybe on analysis these arguments for a teleological explanation of the laws of nature do not fare well, but Rosenberg seems to me mistaken in reaching this conclusion just because there is no teleological explanation by means of the law of nature, i.e., in science.

One might think that our modal judgments about necessity and contingency are simply too unreliable to provide us with any justified conclusions. And one might reject the application of necessity and contingency to things (like the universe or multiverse) rather than to language. But if this is where Rosenberg is coming from, it would be helpful for him to tell us.

3. Rosenberg’s claims about the humanities purporting to describe a realm of selves, meanings, and purposes which is illusory is, like his scientism, open to both charitable and uncharitable interpretations. The human Lebenswelt is a system of representations sustained by the neural circuitry in brains adapted by natural selection to their ancestral natural and social environments. Its contents often cannot be identified with any components of physical reality. The mental is not reducible to the physical; the categories that organize human subjectivity do not smoothly map onto what is objectively there, independent of us. To take a simple and obvious example: blue is a feature of the world of human experience, yet there is a plain sense in which there is in reality nothing blue: no physical object outside the brain and no brain has this property and, if there were immaterial minds, there would be no blue in them: if there are colors they are, after all, properties of two-dimensional surfaces, none of which can be found in a non-physical soul. Our minds represent things as blue but blue is neither a characteristic of our minds nor of the reality it represents. A mental representation of something as blue is not itself blue, no more than the linguistic representation “blue” needs to be blue to do its job. In this way when we speak of things being blue we partake in a kind of illusion. Whether this implies that it would be a good idea, or even possible, to eliminate blue from our conceptual repertoire, foregoing it in favor of remarks like, “That object is reflecting light in the 5000 angstrom wavelength range,” as some eliminativists envisage, is a further question. For most naturalists, physicalists, etc., it’s not obvious that we should or could dispense with the conceptual frame with which evolution has provided us for the sake of ensuring that our minds map cleanly onto reality. The “ontological superficiality” of the human world might be something we cannot escape.

4. Rosenberg is right to say that what we can reasonably say about meaning and purpose, free will, the objectivity of morality is decisively constrained by what science reveals about us and the world we inhabit. His claims about the shape of these constraints are variegated: some seem obvious while others are contentious. Much of what Rosenberg contends science implies is at odds with the traditional image that human beings have of themselves. However, we should not take for granted that what deflates that self-image is ipso facto opposed to the Christian faith, which while calling humans imago Dei also engages in its own deflating of human pretensions.

There are, at some very general level, two great accounts of the world and the place of humans in it. One originates with the pagan Greeks and has enjoyed a very long association with Christianity. The other—the scientific—originates in the late-medieval Christian culture, only after long and hard reflection on the attempt to integrate Christian faith and the Greek legacy, on divine freedom and providence, and on the systemic failure of Aristotelian explanation. Many Christians are enamored of the former account and Rosenberg champions the latter. Both sides are wrong about what scientific naturalism implies about the Christian faith, but I suspect that Rosenberg is right about enough of the other implications to justify his claims about how science scandalizes our image of ourselves. ​