Knuth: Things a Computer Scientist Rarely Talks About 1

Things a Computer Scientist Rarely Talks About

by Donald E. Knuth (Stanford, California:

Center for the Study of Language and Information, 2001), xi+257 pp.

(CSLI Lecture Notes, no. 136.)

ISBN 1-57586-327-8

Japanese translation by Tooru Takizawa, Yuko Makino, and Noboru Tomizawa,

Computer Kagakusha ga Mettanî Kataranaî Koto (Tokyo:

SiBaccess Co. Ltd, 2003),

x+260 pp.

In the fall of 1999, computer scientist Donald E. Knuth was invited to

give six public lectures at MIT on the general subject of relations between

faith and science. The lectures were broadcast live on the Internet

and watched regularly by tens of thousands of people around the world,

and they have remained popular many months after the event. This book contains

transcripts of those lectures, edited and annotated by the author.

After an introductory first session, the second lecture focuses on the

interaction of randomization and religion, since randomization has become a

key area of scientific interest during the past few decades.

The third

lecture considers questions of language translation, with many examples drawn

from the author’s experiments in which random verses of the Bible were

analyzed in depth. The fourth one deals with art and aesthetics; it

illustrates several ways in which beautiful presentations can greatly deepen

our perception of difficult concepts. The fifth lecture discusses what the

author learned from the "3:16 project," a personal exploration of Biblical

literature which he regards as a turning point in his own life.

The sixth and final lecture, "God and Computer Science," is largely

independent of the other five. It deals with several new perspectives

by which concepts of computer science help to shed light on many ancient and

difficult questions previously addressed by scientists in other fields.

A significant part of each lecture is devoted to spontaneous

questions from the audience and the speaker’s impromptu responses,

transcribed from videotapes of the original sessions.

The book concludes with a transcript of a panel discussion in

which Knuth joins several other prominent computer specialists

to discuss "Creativity, Spirituality, and Computer Science."

The other panelists are Guy L. Steele Jr. of Sun Microsystems,

Manuela Veloso of Carnegie Mellon University, and Mitch Kapor

of Lotus Development Corporation, together with moderator

Harry Lewis of Harvard University.

The author has contributed additional notes and a comprehensive index.

More than 100 illustrations accompany the text.

Excerpt from the Foreword by Anne Foerst

Many listeners, particularly students, used the opportunity to ask their

“god” about the questions that bothered them. Don had to address questions

such as, “Why is there evil in the world?”

“What happens after death?”


wanted him to give them answers about the meaning of life, and if there were

any miracles. In short, they treated Don as people within a faith-community

treat their minister.

It didn’t help that Don was absolutely clear about having no authority to

answer these questions. It was particularly upsetting for some people when Don

gave his opinion that the questions have

no objective, universally valuable, and applicable answers;

that everyone has to try to seek answers for themselves. From

the feedback, I gathered that some people were disappointed. But the vast

majority of people were excited. Against all of their prejudices, here was

someone religious who did not claim to own the truth. Instead, Don invited his

listeners to find their own path, of questioning and reasoning about

themselves and all the rest.

The text of this book certainly speaks for itself. I would like to invite the

reader to follow the quest within this book. It was an exciting event at MIT,

and I am convinced that the book can get much of the same spirit across.

I wish the reader fun, anger, excitement, and trouble,

because that is something

only a deeply engaging topic such as religion and science can do for us.

Don has

presented a wonderful way to relate his science and his faith, and I hope the

readers will enjoy it as much as the live audience did.

Other Reviews

Things a Computer Scientist Rarely Talks About is a unique

book. Ultimately its charm lies in the author’s approach to the

subject rather than what he actually finds in the end. As Knuth

himself writes, in discussing the purpose of life, “The important

thing to me … is not the destination, but the journey.”

— Saul A. Teukolsky, Physics Today (April 2002)

One mark of a good author is the ability to make a successful book

out of an unpromising subject. — American Scientist

(May—June 2002)

… a fascinating book. … musings about the interface between computer

science and Christian theology are definitely not what one usually hears

computer scientists talking about, but I’m glad Knuth was willing to

take the risk of discussing them. — Fernando Q. Gouvêa,

MAA Reviews (February 2002)

Lecture 6 was the meat of the book for me, discussing how concepts of

computer science including computational complexity might give insights

about divinity. — Ian Parberry, SIGACT News (December 2002)

Although there is little technical content …, this collection of wisdom

and insights makes fascinating reading … After all, the author says,

“computer science is wonderful but it is not everything.”

Occasionally even mathematicians and computer scientists should think

about the meaning of life. … Each chapter concludes with a really

good set of spontaneous questions from the audience and the speaker’s

impromptu responses, as well as excellent endnotes. — Jerrold W.

Grossman, Mathematical Reviews (November 2003)

Knuth’s involvement was a great boon for MIT’s “God and Computers” project.

— Albert C. Lewis, Zentralblatt MATH 1033 (2004)

… Knuth is courageously unconventional, dealing with theological matters

as a mathematician and computer scientist.

It’s always reassuring, and even inspirational, to see a famous scientist

humbly approach these questions and declare himself confused like the rest of us.

… [The book’s] value is in seeing that computer scientists can and should address

the big issues; and also the uniquely humorous, down-to-earth, and personal way

that he does it. After all, he opens with, “Why I am unqualified to give these

lectures” and then “Why the lectures might be interesting anyway.”

And they certainly are. — Brendan O’Connor, IEEE Annals of the

History of Computing (October—December 2004).

Further notes

This book can be ordered from the publisher


and also from the distributor

(University of Chicago Press).

Curiosity seekers might also want to go back to the

old (1999) webpage

on which the lectures were first advertised.

Videos of the original lectures were hosted for many years by Dr Dobbs Journal,

but all traces of those videos seem to have disappeared. Audio files do survive,

however, thanks to Udo Wermuth:

lecture 1 (6 October 1999]

(Sorry, your browser does not support the audio element.)

lecture 2 (13 October 1999]

(Sorry, your browser does not support the audio element.)

lecture 3 (27 October 1999]

(Sorry, your browser does not support the audio element.)

lecture 4 (3 November 1999]

(Sorry, your browser does not support the audio element.)

lecture 5 (1 December 1999]

(Sorry, your browser does not support the audio element.)

lecture 6 (8 December 1999]

(Sorry, your browser does not support the audio element.)

panel discussion (17 November 1999]

(Sorry, your browser does not support the audio element.)


As usual, I promise to deposit a reward of

0x$1.00 ($2.56)

to the account of the first person

who finds and reports anything that remains technically, historically,

typographically, or politically incorrect.

If you have the original hardback edition of 2001, you might be interested

in its historic errata list,

which enriched the coffers of numerous readers.

Here is a list of all nits that have been picked so far in the first

paperback printing (2003):

page 6, line 5 (14 Nov 2003)

change "in a effort" to "in an effort"

page 23, line 14 (25 Mar 2011)

change "ton, Rouge" to "ton Rouge"

page 35, bottom line (30 Oct 2010)

change "on every" to "on nearly every"

page 36, line 2 (30 Oct 2010)

change "59 pages" to "roughly 59 pages"

page 112, line 1 (18 Nov 2003)

change "Kirsten" to "Kerstin"

page 120, lines 10, 11, 12 (02 Feb 2017)

change "mirror image … didn’t fit" to

"rotation. When I first prepared this image, my combination of the individual layers and color separations was slightly off; the letters didn’t fit"

page 134, line 10 from the bottom (29 Dec 2003)

change "Page 96" to "Page 95"

page 135, line 18 (25 Jul 2011)

change "van Randow" to "von Randow"

page 165, line 6 from the bottom (21 Nov 2003)

change "the the" to "the"

page 200, line 16 (27 Nov 2007)

change "Job 33" to "Job 22"

page 228, line 20 (25 Jan 2007)

change "is to ask is" to "is to ask"

page 237, line 15 (25 Mar 2011)

change "Baton, Rouge" to "ton Rouge"

page 243, Cantor entry (26 Jun 2005)

change "Philip" to "Philipp"

page 245, Dijkstra entry (28 Mar 2005)

change "Wijbe" to "Wybe"

page 252, Planck entry (28 April 2008)

change "Max Karl Ernst" to "Karl Ernst Ludwig Marx (= Max)"

page 253, Randow entry (25 Jul 2011)

change "van" to "von"

page 256, Van Randow entry (25 Jul 2011)

change it to "von Randow", and re-alphabetize

back cover, line 15 (25 Jun 2015)

change "translation,aesthetics" to "translation, æsthetics"

I hope the book is otherwise error-free; but (sigh) it

probably isn’t, because each page presented me with numerous opportunities

to make mistakes. Please send suggested corrections to, or send snail mail to

Prof. D. Knuth, Computer Science Department, Gates Building 4B,

Stanford University, Stanford, CA 94305-9045 USA.

I may not be able to

read your message until many months have gone by, because I’m working

intensively on

The Art of Computer Programming. However,

I promise to reply in due time.


And if you do report an error via email, please do not

include attachments of any kind; your message should be

readable on brand-X operating systems for all values of X.

Don Knuth’s home page

Don Knuth’s book on the 3:16 project

Don Knuth’s other books

Also huffduffed as…

  1. Knuth: Things a Computer Scientist Rarely Talks About: Lecture 1

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