A Guide to Reality, Part 5

Alex Rosenberg, the author of The Atheist’s Guide to Reality, argues that “we should embrace physics as the whole truth about reality”. On the face of it, that’s a remarkable statement open to obvious challenges. 

Rosenberg, however, acknowledges that parts of physics are relatively speculative, unsettled or even inconsistent. It’s the solidly-confirmed part of physics that he’s talking about, the part of physics that is “finished” and “explains almost everything in the universe – including us”. What he’s really claiming, therefore, is that settled physics is the whole truth about reality. 

But is settled physics actually true? Philosophers disagree about what science is, what truth is and, not surprisingly, how close science gets to the truth, but I agree with Rosenberg that settled physics seems to be true. The predictions of special relativity, for example, appear to be 100% correct. (This isn’t to deny that some settled physics might become unsettled one day.) As evidence of the reliability of physics, Rosenberg points out how precise some predictions are: “quantum electrodynamics predicts the mass and charge of subatomic particles to 12 decimal places”. Those predictions are “true” in any reasonable sense of the word, even if physicists eventually refine their predictions to even more decimal places.

Some philosophers and scientists don’t accept Rosenberg’s “scientific realist” view, however. They think science is merely a tool that allows us to get things done. Questions like whether electrons or other theoretical entities really exist as physics describes them are put aside, since they’re viewed as unanswerable and irrelevant. Personally, I think physics allows us to get things done because it’s true, and furthermore it’s true in the sense that the objects and events physics describes are real, whether they’re observable or not. I believe that’s Rosenberg’s opinion too.

The second, more interesting challenge to Rosenberg’s view of physics concerns his claim that settled physics is the “whole” truth about reality. Clearly, there are mathematical and logical truths, which aren’t part of physics, but I take Rosenberg to be referring to truths about the universe and its contents, i.e. “real” stuff.

Nevertheless, if physics isn’t finished, it can’t be the “whole” truth. There must be some physical truths yet to be discovered (for example, what’s the story on dark matter and dark energy, two big things we know little about?). So Rosenberg’s claim that we should embrace settled physics as the whole truth about reality should really be understood as “settled physics is the only truth about reality we currently have”.  

Two obvious questions remain, however. Do we discover the truth from sciences other than physics? And do we learn anything true about the world even when we aren’t doing science?

Well, most people would agree that chemistry, for example, is a science that gets at the truth if any science does. Rosenberg clearly knows about chemistry, so why would he deny that chemistry is as valid as physics? The answer is that he thinks physics has shown there is nothing in the universe except fermions (e.g. quarks) and bosons (e.g. photons). From the idea that fermions and bosons are the only things that really exist, he concludes that all of reality can be explained in terms of those sub-atomic particles. After all, everything in the universe involves elementary particles being somewhere or doing something. Since physics is the science that tells us all about elementary particles and what they do, it’s the fundamental science. Using physics, therefore, we can explain chemistry, which we can then use to explain biology. Another way of saying this is that biology is reducible to chemistry and chemistry is reducible to physics. Knowledge of physics is the only knowledge that counts, because “the physical facts fix all the facts”, including chemical and biological facts.

The big problem with this point of view, aside from the difficulty in actually carrying out such reductions (replacing chemistry with physics, for example) is that fermions and bosons do such interesting things when they interact or are arranged in certain ways. Put some together and you have atoms; put some atoms together and you have molecules; put some of them together and you have cells. Once low-level particles are arranged as, for example, clouds or baseballs or trees, patterns or regularities in the behavior of these higher-level entities emerge. There are new facts to be learned.

If the universe were merely a collection of sub-atomic particles randomly scattered about, there wouldn’t be any chemical or biological facts for chemists and biologists to discover. But the particles in our universe aren’t randomly scattered. They’ve clumped together in various ways. Acquiring knowledge about these clumps (of which you and I are examples) is what chemists, biologists and other scientists (geologists, astronomers, psychologists, etc.) do. Rosenberg knows this, of course, but for some reason downplays it, choosing to focus on physics as the sine qua non of science. In virtue of its power and generality, physics should be embraced as the most fundamental science, but it clearly isn’t the only science worth embracing. 

The other question raised by Rosenberg’s scientism (or physics-ism) is whether we can add to our knowledge when we aren’t doing science at all. Rosenberg doesn’t seem to think so. Although science is built on observation, he is extremely skeptical about what can be learned by simply looking and listening. He also seriously mistrusts introspection. More on this later. 

Next: The 2nd Law of Thermodynamics and us.

A Guide to Reality, Part 4

Chapter 2 of The Atheist’s Guide to Reality is probably the key chapter in the book. That’s where Professor Rosenberg lays out his view of physics and the nature of reality. He doesn’t mince words:

Everything in the universe is made up of the stuff that physics tells us fills up space, including the spaces that we fill up. And physics can tell us how everything in the universe works, in principle and in practice, better than anything else. Physics catalogs all the basic kinds of things that there are and all the things that can happen to them (21).

According to Rosenberg, “we should embrace physics as the whole truth about reality”. Why? Because science is a cumulative process, in which findings are confirmed, corrected or refuted, resulting in a solid foundation. Physicists are still learning things, but the “part of [physics] that explains almost everything in the universe – including us – is finished, and much of it has been finished for a century or more” (21).

Physicists, in particular, have discovered that everything in the universe is composed of either fermions (such as quarks, electrons and neutrinos) and bosons (like photons and gluons), and combinations thereof (like protons and molecules). Fermions are usually associated with matter, while bosons are usually associated with fields and forces. Rosenberg says that’s all there is:

All the processes in the universe, from atomic to bodily to mental, are purely physical processes involving fermions and bosons interacting with one another…Physical theory explains and predicts almost everything to inconceivably precise values over the entire body of data available…From a small number of laws, physics can neatly explain the whole trajectory of the universe and everything in it…The phenomenal accuracy of its prediction, the unimaginable power of its technological application, and the breathtaking extent and detail of its explanations are powerful reasons to believe that physics is the whole truth about reality (21-25).

But what about the other sciences? Surely, chemistry and biology, for example, say something true about reality. Rosenberg, however, argues that physics explains chemistry and chemistry explains biology. Everything that happens in your body is a chemical process, and every chemical process is a physical process:

The only causes in the universe are physical, and everything in the universe that has a cause has a physical cause. In fact, we can go further and confidently assert that the physical facts fix all the facts … including the chemical, biological, psychological, social, economic, political and other human facts (25-26).

He left out the geological and cosmological, but you get the idea. Higher-level sciences are in principle reducible to lower-level sciences. Philosophers call this view “reductionism”. Rosenberg is clearly a “reductionist” of some sort. A similar claim is that all higher-level facts depend or “supervene” on lower-level facts (this principle is called “supervenience”). Rosenberg asks us to imagine two regions of space-time, our own plus another millions of light-years away, in which every fermion and boson is arranged exactly the same way. In such a case, everything else in the two regions would be the same too. Regardless of the regions’ respective histories, if all the sub-atomic particles are arranged the same way, the two regions will contain the same rocks, the same birds and bees, the same political institutions, the same music, the same people with the same memories and thoughts. Physics fixes all the facts.

Next time, before continuing with chapter 2, we’ll consider whether it’s reasonable to “embrace physics as the whole truth about reality”.

A Guide to Reality, Part 1

Alex Rosenberg is the R. Taylor Cole Professor of Philosophy and chairman of the philosophy department at Duke University. He’s published more than 100 articles and reviews. Among his books are Microeconomic Laws: A Philosophical Analysis, Hume and the Problem of Causation, The Structure of Biological Science and Darwinian ReductionismLike most philosophers these days, he writes for an academic audience. In 2011, however, he published a book for a general audience: The Atheist’s Guide to Reality: Enjoying Life Without Illusions.

The title is a little misleading, since Rosenberg derives his atheism from a more fundamental belief called “scientism”. That’s the view according to which, in Rosenberg’s words, “the methods of science are the only reliable ways to secure knowledge of anything”. Unfortunately, there is no word for a person who accepts scientism other than “scientist” and you can be a scientist without believing in scientism. For that matter, you can be an atheist without believing in scientism. 

On the other hand, if you’re sure of God’s existence, The Atheist’s Guide to Reality probably won’t change your mind. It’s a book for people who are willing to take science extremely seriously, even to the point of concluding that many of humanity’s most common beliefs are wrong. Since I’m one of those people, I enjoyed the book, even while disagreeing with some of Rosenberg’s conclusions.

Because The Atheist’s Guide is well-written and covers so much ground (for example, physics, evolution, perception, consciousness, free will, history and morality), I thought it would be an interesting exercise to work through it, explaining and responding to Professor Rosenberg’s views right here on this blog (while continuing to write about other things, like class warfare and mowing the lawn). 

If you want to consider the professor’s views first-hand and be able to correct my account of what he has to say (assuming you want to participate), the paperback and electronic versions are going for less than $15 online.

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Next time:  the relationship between science and atheism.