prior probability

I surveyed some of my previous scholarly works earlier this year, including my probability theory papers, my Coase papers, my Gödel papers as well as my first few scholarly papers, my game theory models, and my turn to legal history. Today, I will survey my book reviews. To the point, I have read a lot of books since I became a law professor, and if one includes my many multi-part write-ups and micro-reviews on this blog (see here, for example) or my sundry informal reviews on Amazon (here), I have probably reviewed several dozens of scholarly books in all. Below, however, are the most notable reviews I have written, in reverse chronological order. (Nota bene: an asterisk indicates an unpublished review.)

1. *Mixed reviews of two new books about Adam Smith, Robin Paul Malloy’s Law and the Invisible Hand: A Theory of Adam Smith’s Jurisprudence and Paul Sagar’s Adam Smith Reconsidered: History, Liberty, and the Foundations of Modern Politics (2024).
2. Mixed review of Ryan Patrick Hanley’s book Our Great Purpose: Adam Smith on Living a Better Life (2023).
3. Positive review of Cheryl Misak’s biography of Frank Ramsey, A Sheer Excess of Powers (2023).
4. *Mixed review of Tyler Cowen’s book Big Business: A Love Letter to an American Anti-Hero (2020).
5. Critical review of Randy J. Kozel’s book Settled Versus Right: A Theory of Precedent (2019).
6. Critical review of Nathan B. Oman’s book The Dignity of Commerce (2017).
7. Positive review of Ullica Segerstråle’s biography of W. D. Hamilton, Nature’s Oracle (2014).
8. Positive review of Jeremy Adelman’s biography of Albert O. Hirschman, Worldly Philosopher (2014).
9. Mixed review of Milton Friedman’s Capitalism and Freedom (2012).
10. *Critical review of David Garrow’s law review article “Mental Decrepitude on the U.S. Supreme Court: The Historical Case for a 28th Amendment” (2007).

One last thing (for now): my most recent reviews (see items #1 and #2 above) revolve around the ideas and works of Adam Smith. As I have mentioned previously, the Scottish philosopher-economist has taken up most of my scholarly attention since the summer of 2020, so stay tuned, for I will have much more to say about my rediscovery of Adam Smith soon …

Check out this 13-minute TED Talk by philosopher Benjamin Mitchell-Yellin, who explains why AI tools like ChatGPT are a virtual Trojan horse: they look like promising solutions to pressing problems but only end up making those same problems worse! He also presents a set of questions to help us guide future decisions on our use of AI. (See also “Everyone Is Cheating Their Way Through College” as well as this more alarmist thread.)

In honor of our new pontiff Leo XIV, who studied mathematics at Villanova University:

David Hume once wrote, “A wise man proportions his belief to the evidence.” (Hume, Of Miracles.) But what about religious claims or paranormal beliefs, i.e. claims where physical evidence is disputed or lacking? Are people who believe in ghosts, telepathy, UFO sightings, alien abductions, etc. (see here, for example) foolish? To this end, I have converted my recent blog posts on Jorge Luis Borges’ Library of Babel into a formal paper — “Belief and Evidence: David Hume in the Library of Babel” — and have just posted my new paper to SSRN. This work is dedicated to my colleague and friend, Todd French (Rollins College), who brought to my attention two books that have ended up having a profound impact on my thinking on these questions: Jeffrey Kripal, Authors of the Impossible (2010), and Tanya Luhrman, When God Talks Back (2012). More generally, French, Kripal, and Luhrman have caused me to rethink my Humean priors regarding the relationship between evidence and belief.

Why do I even need an ID (i.e. internal passport) at all to travel inside my own country? Bonus question: How many more erosions of liberty (anti-smoking rules, seat belt laws, etc.) before we stop being a “free” country?

Via Vatican News: “The upcoming Conclave starting on May 7 to elect the 267th Pope will be the 76th in the form we know today, which was established by Pope Gregory X in 1274, and the 26th held under the gaze of Michelangelo’s Last Judgment in the Sistine Chapel.” See also this 2013 report by Jason Horowitz, via The Washington Post.

Now that I have brought my 11-part series on “David Hume in Borges’ Library of Babel” to a close, what better way of marking the end of this intellectual escapade than with a melancholic piece of music performed by one of my favorite musicians of all time — the late great Argentine tango composer and virtuoso bandoneónist, Ástor Pantaleón Piazzolla (1921-1992):

I will conclude my series on “David Hume in the Library of Babel” by returning to to the question I posed in my previous post: Why hope? Why faith? Hope/faith/belief that the decoder book or master index will one day be found or rediscovered. Hope that the incomprehensible volumes of the infinite hexagons are full of meaning. Hope that the Universal Library contains some secret sequence, that it “is unlimited but periodic.” While others are driven to suicidal despair, our narrator remains full of hope.

A potential clue to this puzzle is the concept of the “infinite.” In all, our unnamed narrator employs this word eight times. (See Borges 1998/1941, Paras. 1, 2, 7, 14, & 15.) But is the Library really “infinite”? And if not, where are its outer limits? Alas, The Library of Babel is full of contradictions. On the one hand, we are told in the first and last paragraphs of the story that the Universal Library “is composed of an indefinite, perhaps infinite number of hexagonal galleries” and that it is “unlimited.” But at the same, we are also told in the middle of the story that the total number of tomes, though astronomically large, is not infinite: “the Library is ‘total’—perfect, complete, and whole—and … its bookshelves contain all possible combinations of the twenty-two orthographic symbols (a number which, though unimaginably vast, is not infinite) ….” How can an infinite Library not contain an infinite number of books? Or, what about our Universe? Is the Universe infinite? Alas, scientists still don’t have a definitive answer, for while the observable universe is finite, with a radius of about 46 billion light-years, the total universe could be larger, potentially infinite.

Perhaps there are some things we cannot assign a Humean probability value to, such as the infinite or the impossible. Consider once again the possibility of a decoder book or master index. If such a literary holy grail were to exist, will it ever be found? Or to put this question in Humean terms (cf. Hume 1748), is the probability p₁ of locating the Universal Library’s master index higher or lower than the probability p₂ that any of the miracles reported in the New Testament Gospels of the Bible really happened? Alas, given the astronomical size of the Universal Library and the historical distance between our day and Biblical times, how would we even begin to quantify such probability values? So, what is to be done? What happens when we cannot assign probability values to carry out Hume’s probabilistic test?

What if the decision to believe in God—or in any other impossibility or improbable possibility, I might add—is not so much a belief but a lifestyle: “a choice founded not on evidence but on the way we choose to live in the face of inadequate evidence.” (Tanya Luhrman, When God Talks Back, p. xiv) In other words, what if we turn Hume’s argument against miracles—and religious skepticism more generally—on its head? Or to quote Tanya Luhrman again: “If you could believe in God, why wouldn’t you?” (Ibid., p. xvi)

On this Luhrmannian view of Borges’ Library of Babel, our narrator has “out-Humed” David Hume. Despite the lack of any direct evidence that the randomly-arranged and composed books in the Universal Library have any meaning, the narrator still holds out hope that those incomprehensible and indecipherable volumes are susceptible to cryptographic methods or allegorical readings. How could it be otherwise, for without this hope, where would we find the requisite curiosity and motivation to make sense of the impossible?

Act III, scene iii of David Hume in the Library of Babel

Below are the last two paragraphs of Jorge Luis Borges’ short story “The Library of Babel.” Here, the Argentine author (pictured above) concludes his story by contrasting “the present condition of humanity” (which teeters at the verge of extinction!) with the “elegant hope” that the books in the Universal Library have meaning:

Methodical composition distracts me from the present condition of humanity. The certainty that everything has already been written annuls us, or renders us phantasmal. I know districts in which the young people prostrate themselves before books and like savages kiss their pages, though they cannot read a letter. Epidemics, heretical discords, pilgrimages that inevitably degenerate into brigandage have decimated the population. I believe I mentioned the suicides, which are more and more frequent every year. I am perhaps misled by old age and fear, but I suspect that the human species—the only species—teeters at the verge of extinction, yet that the Library—enlightened, solitary, infinite, perfectly unmoving, armed with precious volumes, pointless, incorruptible, and secret—will endure.

I have just written the word “infinite.” I have not included that adjective out of mere rhetorical habit; I hereby state that it is not illogical to think that the world is infinite. Those who believe it to have limits hypothesize that in some remote place or places the corridors and staircases and hexagons may, inconceivably, end—which is absurd. And yet those who picture the world as unlimited forget that the number of possible books is not. I will be bold enough to suggest this solution to the ancient problem: The Library is unlimited but periodic. If an eternal traveler should journey in any direction, he would find after untold centuries that the same volumes are repeated in the same disorder—which, repeated, becomes order: the Order. My solitude is cheered by that elegant hope. [Borges 1998/1941, Paras. 14-15; emphasis in the original; footnote omitted]

The final word of the final sentence of the final paragraph of the story is the word “hope.” (Borges 1998/1941, Para. 15) But why is the narrator of the story so hopeful, especially considering the penultimate paragraph of the story, which paints a bleak and foreboding picture of “the present condition of humanity.” (Ibid., Para. 14) Mankind is on the verge of intellectual and physical extinction: illiterate and ignorant youth blindly worship books they cannot read. Others ignite brain epidemics, commit heresies, or embark on “pilgrimages that inevitably degenerate into brigandage,” all of which have “decimated” the library’s frail and teetering population. Still others resort to suicide. Although the doom and gloom and foreboding of many of the previous paragraphs all come to a head here, what is most surprising to me is that this dark picture still contains a ray of hope: the Universal Library will endure, even if humanity does not.

So, why is the narrator so hopeful? I will consider this question and conclude my series on “David Hume in the Library of Babel” in my next post.