With just over a month to go, it's safe to say this book will easily make my top ten list for 2018 non-fiction. The author, Sean Carroll, is on the research physics faculty at Caltech (but don't hold that against him). When he writes about physics, you can pretty much take it to the bank: he may be dumbing it down a bit, but he's not leading you astray.
His goal here is to apply the insights of science to (see the title) the "big questions". He describes his approach as "poetic naturalism" (a philosophical realm apparently inhabited by one adherent, Sean Carroll, but that's okay). The "naturalism" part is meant to eschew philosophical explanations that appeal to anything beyond the physical world of atoms and forces, as described by what Carroll calls the "Core Theory", a mostly-complete description of how everything is made up of bosons, fermions, and the sorta-well-known interactions between them. Carroll asserts, and I don't doubt it, that our observations do not reveal anything in everyday macroscopic reality that can't be explained, at bottom, by the Core Theory. (It's known to break down in extreme situations, and may not describe possible forces or particles that might be found in the future, but Carroll explains that such caveats are irrelevant to our common experience.)
So: no supernatural beings, no eternal souls, no ESP, no magic, no no Nanette.
Except Carroll does something extraordinary here: he doesn't dismiss various forms of supernaturalism out of hand: he engages the best arguments for them, takes them seriously, argues against them fairly and convincingly, without a whiff of condescension or arrogance.
He's also extremely honest about what he (by which I mean, science) doesn't know, at least not yet. And also honestly admits that nothing is certain. For example: we can't prove that the world, and the observable universe, wasn't created 6000 years ago, with all its galaxies and fossils. Or for that matter, created fifteen minutes ago, including you and all your phony memories. Or that we aren't brains in a vat, or part of a large computer simulation, or….
But that's not the way to bet. Carroll takes a uniquely Bayesian view to such issues, calling the probabilities Bayes described as "credences": we don't hold any beliefs with 100% certainty, but we might have a 99.999…% credence. String out as many 9s as you feel comfortable with.
So that's naturalism. What's the "poetic" part? It tells us that there's "more than one way to talk about the world". Specifically (page 20):
- There are many ways of talking about the world.
- All good ways of talking must be consistent with one another and with the world.
- Our purposes in the moment determine the best way of talking.
A good example of Carroll's approach is found in his (again, relentlessly fair) discussion of "free will", a bugaboo of mine.
Heh. Carroll can't deny that, reduced to basics, there's nothing magical going on in our bodies beyond the deterministic (or, with quantum mechanics, probabilistic) interactions between atoms, microscopically manifested as firing neurons, biochemical pathways, proteins yanking on each other, etc., everything working itself up to me typing away at this keyboard.
But, Carroll notes, that's not a lot of help when you look into your closet in the morning and try to decide which shirt to wear. Try saying: "Well, I'll just stand here and let the atoms in my body do whatever they were deterministically going to do anyway."
Wait as long as you need to before you're convinced that that the atoms in your body aren't gonna get that shirt-picking job done for you. Or go to work bare-chested. Your call.
But that's just one example, the book really is the "Big Picture", covering most of the contentious questions of existence. If at times it seems that Carroll's discussion is at the level of late night college dorm room arguments, well… that's pretty much the level beyond which many philosophical discussions have failed to progress in centuries.
Carroll has a chapter on the "is-ought" dichotomy, and the impossibility
of jumping between them. But (see above) his poetic-naturalism tenets
use ought-words like "good" and "best" without (as near as I can tell)
strong justification. "Good", by what standard, and why should I buy
that standard and not some other?
I sometimes worry about the power of language to mislead us down false
paths in search of Truth. This is especially applicable in purporting to
answer the Big Questions; are human-invented grunts and their squiggly
representations on the page really the best tools to do that? Especially
when we know languages are replete with ambiguity and imprecision?
I mean, every logical fallacy ever committed was committed with language.
Probably related: Carroll assumes the universe is completely
understandable by human minds. But what if it's not?
I've said this before, but: I have a dog.
A very smart dog.
But I won't try to teach him calculus. It's pretty clear that would be a waste of time. He wouldn't understand.
And (worse) my dog wouldn't even understand that he's failing to understand. He would be unaware that he's missing fundamental pieces of knowledge.
Human brains are (generously) only about 20 times bigger than dog brains. Is that big enough to completely understand reality?
I'm not sure about that. And I'd say "It's something to think about", except I'm not sure that we have adequate brain power to even do that.
But (all in all) I highly recommend this book if the topics seem interesting to you at all. The book is full of insight and wit, very accessible to (say) a bright high schooler or STEM-capable undergrad. (Grad-level stuff is relegated to an appendix.)