Hacker News new | past | comments | ask | show | jobs | submit login
Raymond Smullyan has died (nytimes.com)
363 points by kawera on Feb 12, 2017 | hide | past | web | favorite | 60 comments

When I was an undergraduate I met Raymond at a math conference in Minnesota. We talked about logic, religion, and philosophy at the reception the first night. The next morning he sees me and runs over to me. He said,

"I invented a new religion for you last night. God has a number in mind. If the sum total of all good acts minus the sum total of all bad acts exceeds this number then everyone goes to heaven. Otherwise, everyone goes to hell. Imagine then. Something you do could send everyone to hell."

I'm sad to hear of his passing.

Apparently this scene from The Labyrinth is based on the heaven/hell logic puzzle he devised: https://www.youtube.com/watch?v=ReFhu8KYbmU

> Many of his logic problems are extensions of classic puzzles. Knights and Knaves involves knights (who always tell the truth) and knaves (who always lie). This is based on a story of two doors and two guards, one who lies and one who tells the truth. One door leads to heaven and one to hell, and the puzzle is to find out which door leads to heaven by asking one of the guards a question. One way to do this is to ask "Which door would the other guard say leads to hell?". This idea was famously used in the 1986 film Labyrinth.

According to: https://en.wikipedia.org/wiki/Raymond_Smullyan

Life is something like this, except that with more powerful weapons and means for making global warming over time, less and less bad acts are needed to send everybody to hell.

Anyways, I loved reading his books as a child.

Wow this is such a wholesome thing to say. I have no idea who this guy is but I now regret never meeting him.

Myself, as well. It's been some time since I last read his books, but his name crossed my mind a few times in the last few years, and I'd wondered if he could actually still be around.

Wish I've looked into that sooner.

"The Lady or the Tiger" is, quite literally, probably the single most influential book from my childhood. In 6th grade, my math teacher had a copy in his classroom. He noticed that I spent so much time before class, after class, (during class) reading it, that at the end of the school year he told me I could take it home so long as I promised to bring it back at the end of the summer. (He was also the 7th and 8th grade math teacher.)

I took that book home and treasured it for the whole summer, pouring over each puzzle, solving each one without peeking at the answers, then comparing my answers to the ones in the back of the book. By the end of the summer I think there were only 1 or 2 I hadn't been able to work out myself. Sure enough, as the first day of 7th grade rolled around, it was in my backpack and promptly returned to the shelf of my math teacher's classroom. Satisfied that I had gotten all I could from "The Lady or the Tiger", I next turned my attention to the Apple IIe he had sitting in the corner and a book entitled "Apple Basic".

The rest, as they say, is history.

One final note...as I continued through school and university, I gradually came to realize that Taoism was the school of philosophy that matched most closely to how I understood the world and is, in some sense, the closest thing I have to a "religion". It wasn't until much later in life (well after I turned 30), that I happened to stumble back across Smullyan and his writings, only to discover that he was also a rather adroit Taoist philosopher. (His "Is God a Taoist?" essay, http://www.mit.edu/people/dpolicar/writing/prose/text/godTao... is highly recommended.)

To this day I wonder if "The Lady or the Tiger" didn't have more of an impact on my early development than simply fostering a love of logic...

Thank you a lot for linking the "Is God a Taoist?" Essay. For somebody as young and easily influenced as me (who is currently not very involved in philosophy and religion) it might actually have a great impact on my understanding of both - or at least it is an excellent starting point for further thoughts on the subject.

If this interests you I can highly recommend the book 'Trying Not To Try'!


"Oh come off it! You're not now talking to your Sunday school teacher, you are talking to me."

Someone once said that it isn't philosophy if it doesn't make you laugh. (If it only makes you laugh, it's not good philosophy.) It may have been Smullyan.

I loved the puzzle books, even though I wasn't very good at the puzzles. The titbit about his wife is this story (https://magazine.uchicago.edu/9506/June95BOBProfiles.html, NYT left out the actual puzzle)

> Smullyan admits the following puzzle might have come in handy had he designed it before meeting his wife.

> "I'll make a statement. If the statement is true, you give me your autograph. It doesn't have to be on a check, it can be on a blank piece of paper. If the statement is false, you don't give me your autograph," Smullyan sets up the puzzle. "Well, my statement is, `You will give me neither your autograph nor a kiss.'

And his puzzles always came with variations, like this (http://blog.tanyakhovanova.com/2010/05/raymond-smullyans-mag...):

> Afterwards, Raymond Smullyan joined me in the elevator. “Do you want to see a magic trick?” he asked. “I bet I can kiss you without touching you.” I was caught off guard. At that moment I believed anything was possible. I agreed to the bet.

> He asked me to close my eyes, kissed me on the cheek and laughed, “I lost.”

And this bit from the preface to The Lady or the Tiger aptly summarizes most people's attitude towards maths:

> Before he called the boy to the phone, the father said to me in soft conspiratorial tones: "He is reading your book and loves it! But when you speak to him, don't let him know that what he is doing is math, because he hates math! If he had any idea that this is really math, he would stop reading the book immediately!"

The New York Times says that Raymond Smullyan is dead? I'm not sure I believe it.

If I asked CNN whether Fox News would answer "da" if asked whether Smullyan is dead, would they answer "ja"?

I don't think people get the reference. Your post was in good taste. For those who don't understand look up the hardest logic puzzle.


Isn't this a spoiler? I haven't seen the puzzle in a while.

Not really. At worst it's a hint that asking hypothetical questions about how other gods would answer questions is useful.

That makes sense, in which case someone who's already had some experience thinking about liars-and-truthtellers puzzles gets nothing out new of it, and those are probably the overwhelming majority anyway.

Coming across The Tao is Silent in college changed my life forever. I've subsequently recommended it to select friends who seemed like they'd benefit from it and they've reported back and told me the book has had similar effects within their life. When I introduce Smullyan to people I explain that he is basically an IRL gandalf math/spirituality wizard.

I just picked up A Spiritual Journey and Set Theory And The Continuum Problem several weeks back. Both of these books feel like they are personal, and direct mathematical and spiritual conversations that are directed towards an audience very much like myself. I told my dad (a practicing amateur number theorist) a few weeks back that the set theory book in particular made me feel like I'd found a mathematical topic (foundations of logic) that really spoke to me and even the first few chapters had clarified some confusion within the area that I'd been carrying for years.

This feels much like I felt a few weeks ago when I found myself regretting that I'd never sent Obama a letter during his presidency and would never get the chance again.

Godspeed Professor Smullyan and thank you for everything you shared with us along the journey!

PS thank you to everyone in this thread who has shared their connection to this wonderful man, it's really heartening to find some community amidst this loss.

> I found myself regretting that I'd never sent Obama a letter during his presidency and would never get the chance again

As one door closes, another opens. You have the chance to send Trump a letter.

My favorite Smullyan book is out of print: Forever Undecided: A Puzzle Guide to Gödel. Gödel's paradoxical theory hooked me in college, and after twenty years I still can't help but feel that it has a message for us---not in the word-play associations that some philosophers mistreat such things, but more in its implications for the human mind and artificial intelligence, along the lines that Roger Penrose explores. I've read Franzén's rejection of all attempts to "apply" Gödel's proof, and yet, I keep coming back to the idea that we can see our way "out" of these limited systems.

Anyway, Smullyan's book is a real treat. In the later chapters he even goes beyond Gödel. I've never completely figured out how much of that is Smullyan and how much is other published research.

One of my favorite Smullyan works is the lesser-known 5000 B.C. and Other Philosophical Fantasies. Here's one of the more amusing anecdotes from that book:

In item #249 of my book of logic puzzles titled What Is the Name of This Book?, I describe an infallible method of proving anything whatsoever. Only a magician is capable of employing the method, however. I once used it on [noted philosopher] Rudolph Carnap to prove the existence of God.

"Here you see a red card," I said to Professor Carnap as I removed a card from the deck. "I place it face down in your palm. Now you know that a false proposition implies any proposition. Therefore, if this card were black, then God would exist. Do you agree?"

"Oh, certainly," replied Carnap, "if the card were black, then God would exist."

"Very good," I said as I turned over the card. "As you see, the card is black. Therefore, God exists!"

"Ah yes!" replied Carnap in a philosophical tone. "Proof by legerdemain! Same as the theologians use!"

His book 'The Lady or the Tiger' came at a pivotal point in my life in my early forties, actually helped lift me out of a deep depression upon being separated from my children. I had planned to write him to see if I could visit him, but never did. He inspired me, and has touched my children's lives as well. A great human being. I'm saddened upon waking to this news. I had hoped the NYT was an errant knight in this case.

Relevant here, anyone interested in combinatory logic (functional programming, etc.) should check out To Mock a Mockingbird. It’s a lovely puzzle book which teaches the subject through direct experience.

Folks also might enjoy The Magic Garden of George B. (And of course, all of Smullyan’s other books.)

His philosophy of teaching was a little puzzling. “My policy is to teach the student as much as possible and to require from him or her as little as possible,” he told Donald Albers and Gerald Alexanderson, the authors of “Mathematical People: Profiles and Interviews” in 2008.

But, he added, the impact of his apparent lenience was that many of his students worked harder in his course than in any other.

Would love to see more studies around this methodology and its impact on students. Not only an incredible professor, but an innovative teacher. Rest in peace!

I can't remember if it was via reading Douglas Hofstadter, Daniel Dennett, William Poundstone (or someone writing in a similar vein) that I came across Smullyan but his name cropped up in many things that have captivated me over the years.

This dialogue is absolutely marvellous: http://www.mit.edu/people/dpolicar/writing/prose/text/godTao...

It might have been Hofstadter and Dennett's "The Mind's I" which includes both "Is God a Taoist?" and "An Unfortunate Dualist"

Yep. That was it. I still have a copy. Amazing book - even if I'm not sure I agree with either of them on the nature of consciousness any more.

One of my favorite books is the "The Chess Mysteries of Sherlock Holmes" which describes a technique called retrograde analysis


I found this book after reading The Flanders Panel, a thriller novel that also uses retrograde chess analysis. Both great books.

same here; in fact it might have been the first smullyan book I read, since I was a huge sherlock holmes fan before I ever heard of him

Some years back, I worked in a library. Having loved one of Smullyan's books, I searched for more. One book that came up didn't have a title in the system. Puzzled, I wrote down the call number, went to the shelf, and grabbed the book. It was "This Book Needs No Title". Clearly whoever added it to the catalog was inspired by Smullyan's prankster ways.

I'm surprised to learn that he's from Far Rockaway (just like Feynman). I had assumed he was British for some reason.

could it be that he looked like dumbledore?


One of my favorite pieces of Smullyan's writing is "Planet Without Laughter": http://www-cs-faculty.stanford.edu/~uno/smullyan.html

Here's my favorite, "Is God a Taoist?": http://www.mit.edu/people/dpolicar/writing/prose/text/godTao...

My favorite too, and also my first encounter with his writings. Read it back in the eighties as it was one of the writings discussed in "The Mind's I". It was exactly the type of initial clarification I needed to read at the time and definitely shaped my understanding on what the term "God" might point to at a time when all the other options seemed petty and infantile to a curious and perplexed teenager.

Wow. Sad to hear about his passing. He set the initial path for much of my subsequent interests.

That's also in his book "The Tao is Silent". I picked this book off the library shelf at random, so many years ago, and couldn't stop reading the lovely, approachable writing. He helped me think through and finally rid myself of all the fundy Christian mental baggage leftover from when I was a kid.

I own a few of his puzzle books, and even have solved some of their puzzles.

Some are so amazingly difficult that it's hard to understand how someone could be that smart.

Couple that with what everyone I've ever heard say about him, the person... that he was a wonderful, caring generous man.


Challenged by What Is the Name of This Book but loved it.

If Hofstadter hadn't changed my life forever, maybe Smullyan would have.

I don't have much to add, except that when I read his books -- for me, the ones I fell in love with were The Lady or the Tiger, What is the Name of this Book? and To Mock a Mockingbird -- I felt I was communing with a spirit for whom wit, delight, charm and generosity were one. I'm delighted, and not a bit surprised, to hear he had this sort of presence in person.

OH YEAH also Alice in Puzzleland! That might be the very best. Highest possible recommendation.

Smullyan's book on First-Order Logic is still the best textbook I have ever read in any subject. I wish more people would write as succinctly as he did.


I have taken classes from fitting and joined colloquiums from Raymond. Learned a lot from them. RIP.

In high school I enjoyed reading "What Is the Name of This Book?" Lots of fun.


This is why I love coming to HN. Once in a while you discover something really beautiful. I come from India & never heard of Raymond Smullyan, but I just discovered his wonderful puzzles & writings. Thanks.

Same here. I spent a full day reading the various articles linked to from this thread, and buying/reading his book on Taoism and more. HN at its best!

Why publishers of his books are not publishing in some ebook platforms at least some of them like "to mock mocking bird" or I fail to find it on amazon kindle or google ebooks

Thanks although not available in the uk unfortunately

Also no ebook of "Gödel, Escher, Bach: An Eternal Golden Braid"

Given what I know of Smullyan, my guess is that he died very gracefully. Perhaps he was even looking forward to venturing into the great Unknown. Godspeed.

this is very sad. I live blocks from Lehman college but that was a few decades before my time (if he taught in 1979). Unrelated, there is also Melvyn Nathan who does additive combinatorics.

The Tao is Silent.

RIP, Sir


We detached this subthread from https://news.ycombinator.com/item?id=13626884 and marked it off-topic.

I think this is about policing yourself and understanding the outcome of your own acts rather than policing others of their acts. Imagine a community where everyone is responsible for their own behavior.

If someone is expected to commit two more bad acts than good acts, then it's better to kill him/her immediately. It's better for everyone, even for his/her eternal soul. Looks like a nice society to live in.

Note that present day religions all are about how other people should live, not just about how you should live.

Oh, I don't know, Buddhists and Taoists are pretty chill about this. Modern Judaism too.

Pope Francis has also made a big point of not judging others and trying to shift Catholicism back to its roots of faith and charity rather than being hypocritical morality enforcers. Not clear he will succeed long run, but there is a recognition in big places that doctrinal Christianity has lost its way.

> trying to shift Catholicism back to its roots of faith and charity rather than being hypocritical morality enforcers.

How are faith & charity different from any other moral issue? Why do you (apparently) think encouraging faith & charity is okay, but (apparently) not humility, chastity, temperance, prudence &c.?

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact