The essential Turing: seminal writings in computing, logic, philosophy, artificial intelligence, and artificial life, plus the secrets of Enigma

622 Pages·2004·3.33 MB·english

by  Alan M. Turing

The Essential Turing:
Seminal Writings in
Computing, Logic, Philosophy,
Artificial Intelligence, and
Artificial Life:
Plus The Secrets of Enigma
B. Jack Copeland,
Editor
OXFORD UNIVERSITY PRESS
The Essential Turing
AlanM.Turing
The Essential Turing
Seminal Writings in Computing, Logic, Philosophy,
Artificial Intelligence, and Artificial Life
plus The Secrets of Enigma
Edited by B. Jack Copeland
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Acknowledgements
Work on this book began in 2000 at the Dibner Institute for the History of
Science and Technology, Massachusetts Institute of Technology, and was com-
pletedattheUniversityofCanterbury,NewZealand.Iamgratefultoboththese
institutions for aid, and tothe followingfor scholarly assistance:JohnAndreae,
Friedrich Bauer, Frank Carter, Alonzo Church Jnr, David Clayden, Bob Doran,
Ralph Erskine, Harry Fensom, Jack Good, John Harper, Geoff Hayes, Peter
Hilton, Harry Huskey, Eric Jacobson, Elizabeth Mahon, Philip Marks, Elisabeth
Norcliffe,RolfNoskwith,GualtieroPiccinini,Andre´sSicard,WilfriedSieg,Frode
Weierud, MauriceWilkes,MikeWoodger, andespeciallyDianeProudfoot. This
book would not have existed without the support of Turing’s literary executor,
P. N. Furbank, and that of Peter Momtchiloffat OxfordUniversity Press.
B.J.C.
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Contents
Alan Turing 1912–1954 1
Jack Copeland
Computable Numbers: A Guide 5
Jack Copeland
1. On Computable Numbers, with an Application to the
Entscheidungsproblem (1936) 58
2. On Computable Numbers: Corrections and Critiques 91
Alan Turing, Emil Post, andDonald W. Davies
3. Systems of Logic Based on Ordinals (1938), including
excerpts from Turing’s correspondence, 1936–1938 125
4. Letters on Logic to Max Newman (c.1940) 205
Enigma 217
Jack Copeland
5. History of Hut 8 to December 1941 (1945), featuring an
excerpt from Turing’s ‘Treatise on the Enigma’ 265
Patrick Mahon
6. Bombe and Spider (1940) 313
7. Letter to Winston Churchill (1941) 336
8. Memorandum to OP-20-G on Naval Enigma (c.1941) 341
Artificial Intelligence 353
Jack Copeland
9. Lecture on the Automatic Computing Engine (1947) 362
10. Intelligent Machinery (1948) 395
viii | Contents
11. Computing Machinery and Intelligence (1950) 433
12. Intelligent Machinery, A Heretical Theory (c.1951) 465
13. Can Digital Computers Think? (1951) 476
14. Can Automatic Calculating Machines Be Said to Think? (1952) 487
Alan Turing, RichardBraithwaite, Geoffrey Jefferson,
and MaxNewman
Artificial Life 507
Jack Copeland
15. The Chemical Basis of Morphogenesis (1952) 519
16. Chess (1953) 562
17. Solvable and Unsolvable Problems (1954) 576
Index 597
Alan Turing 1912–1954
Jack Copeland
Alan Mathison Turing was born on 23 June 1912 in London1; he died on 7
June 1954 at his home in Wilmslow, Cheshire. Turing contributed to logic,
mathematics, biology, philosophy, cryptanalysis, and formatively to the areas
later known as computer science, cognitive science, ArtiWcial Intelligence, and
ArtiWcialLife.
Educated at Sherborne School in Dorset, Turing went up to King’s College,
Cambridge,inOctober1931toreadMathematics.Hegraduatedin1934,andin
March 1935 was elected a Fellow of King’s, at the age of only 22. In 1936 he
publishedhismostimportanttheoreticalwork,‘OnComputableNumbers,with
an Application to the Entscheidungsproblem [Decision Problem]’ (Chapter 1,
with corrections in Chapter 2). This article described the abstract digital com-
puting machine—now referred to simply as the universal Turing machine—on
which the modern computer is based. Turing’s fundamental idea of a universal
stored-programme computing machine was promoted in the United States by
JohnvonNeumannandinEnglandbyMaxNewman.Bytheendof1945several
groups,includingTuring’sowninLondon,weredevisingplansforanelectronic
stored-programme universaldigitalcomputer—a Turing machine inhardware.
In 1936 Turing left Cambridge for the United States in order to continue his
research at Princeton University. There in 1938 he completed a Ph.D. entitled
‘Systems of Logic Based on Ordinals’, subsequently published under the same
title(Chapter 3,with furtherexpositioninChapter4). Nowaclassic, thiswork
addressestheimplicationsofGo¨del’sfamousincompletenessresult.Turinggave
anewanalysisofmathematicalreasoning,andcontinuedthestudy,begunin‘On
Computable Numbers’, of uncomputable problems—problems that are ‘too
hard’to be solvedbya computing machine (evenone with unlimited time and
memory).
Turing returned to his Fellowship at King’s in the summer of 1938. At the
outbreak of war with Germany in September 1939 he moved to Bletchley Park,
the wartime headquarters of the Government Code and Cypher School (GC &
CS). Turing’s brilliant work at Bletchley Park had far-reaching consequences.
1 At2WarringtonCrescent,LondonW9,wherenowthereisacommemorativeplaque.