One chill Paris night shortly before the turn of the millennium, Jim Holt stood on the Ponts des Arts smoking, looking down at the Seine, and pondering Leibniz's old question "Why is there Something and not Nothing?" Maybe I should write a book about it, he mused. And now he has.
Why Does the World Exist? chronicles Holt's decade-long expedition into the mystery of existence. Not just your existence, or mine. Everyone's and everything's.
In pursuit of an answer he encounters theists and atheists, physicists and philosophers, Platonists (to whom he gives particularly short shrift) and Hegelians. The result is a fascinating, if ultimately flawed book.
Part of the problem is that the exposition quickly settles into a routine: Holt encounters, either in print, or more often in person, each next wise man (I can't recall him mentioning any women -- women find existence less problematic than men do, I suppose). He then converses at length with his subject and departs.
The French have a phrase for what invariably happens next: l'esprit de escalier (the wit of the staircase), by which they mean what would have been the perfect comeback if only it had occurred to you at the time, and not when you were stomping down the stairs on your way out. But the advantage to staircase wit is: you get to have the last word -- if only to yourself. And so it is that, unhampered by any rejoinders, Holt adroitly dispatches the argument of each successive wise man and moves on to the next.
No doubt some such structure is needed to keep the narrative moving forward: After all, if Holt were to give us The Answer in, say, Chapter 3, why would we bother reading on? But the repetitiveness does begin to get wearing after a while. So I was relieved when, somewhere toward midpoint, a break in the pattern occurred.
Because there, in the midst of all the "metaphysical fun" (Holt's term, not mine), we get a heartrending little vignette. On the brink of an interview with cosmologist Steven Weinberg of The First Three Minutes fame, Holt is called home to New York from Austin, because his long-haired dachshund Renzo has been diagnosed as dying of cancer. Having gone through something not wholly dissimilar myself this year, I can appreciate how the for-real encroachment of Nothingness puts an end to all our toying with imagined notions of it. The final breaths of a beloved pet come to outweigh the first minutes of the universe as a whole.
Yet even in extremis, Holt can't quite bring himself to live in the world whose existence he is laboring so hard to ground: As Renzo's euthanizing injection is taking effect, he maintains his composure by mentally working out the implications of one of Fermat's prime number theorems. The scene seems emblematic of the book as a whole: absorption in intellectual puzzles to keep from sobbing while awaiting the end.
After this brief real-world interlude, the above thesis-antithesis-with-never-a-synthesis dialectic resumes. Until near the end, when Holt surprised me again by actually answering, to his own satisfaction at least, the Question he started out with.
SPOILER ALERT! FOLLOWING DISCUSSION DISCLOSES JIM HOLT'S CONCLUDING "PROOF"
Holt begins by reviewing all the explanations seen so far as to why Something might exist rather than Nothing: The world came into existence in obedience to some principle of simplicity or fecundity or ethical goodness or sheer randomicity or what have you. Then, following Derek Parfit, he abstracts a single structure from this welter of competing hypotheses -- namely, they all posit the operation of some sort of Selector in bringing the world into being.
This, however, immediately raises the question of what selected the Selector.
Sidestepping the implicit infinite regress, Holt goes with a two-tiered Selector/MetaSelector solution, which in turn leads him to conclude -- through a chain of logic which, though clear enough, is a bit too convoluted to recapitulate here -- that the MetaSelector that ultimately caused our world to exist operated to select for ... mediocrity. "The cosmic possibility selected ... to be reality would be thoroughly mediocre" (Holt's emphasis, p. 240).
And here, I'm afraid, I must part company with Jim and his magical mystery tour. His "proof" disregards one feature of our universe that he had explored earlier in detail -- namely that, whatever else the engines of creation selected for, they selected for us. And, in the process, they had to fine-tune the fundamental parameters of physics in such a way as to make matter, stars, planets, life, and intelligence all possible. Whether you prefer to explain our own extremely unlikely existence as nonetheless inevitable given a multiverse of infinitely many parallel realities, or as owing to the operation of some anthropic principle, the fact remains: Here we are.
Why, then, should a universe chosen utterly at random, a thoroughly generic universe to use Holt's term, have included us? To be sure, Holt does assert that his mediocre universe would be infinite in some sense, but not infinite enough to include every roll of the dice. It would rather be a discrete, denumerable infinity -- one that encompasses the integers only, and not even all of them (see pp. 240-1).
On the other hand, the likelihood is that reality, at its most fundamental level, is not discrete but continuous, not digital but analogue, based on real numbers rather than integers (see, e.g., David Tong, "The Unquantum Quantum," Scientific American, December 2012). What that means is that an aleph-null infinity couldn't even begin to cover all the bases, much less the home run that accounts for our own existence.
The constraints applied by physics -- a physics that somehow leads to us -- may not be enough to justify the world on their own, but that doesn't mean they can be swept under the rug.
All that said, kudos are due to Jim Holt for this book. If he has not supplied The Answer, at least he has come to grips with The Question.
Previously web-published on GoodReads.
Bill DeSmedt is a philosophical dilletante and author of the cult classic science thriller Singularity, as well as its forthcoming (and more philosophical) sequel Dualism.