The Second Industrial Revolution

1. Duncan Bythell, The Handloom Weavers: A Study in the English Cotton Industry during the Industrial Revolution, p. 70.

2. Bythell, "The Coming of the Powerloom," The Handloom Weavers, pp. 66-93.

3. Malcolm I. Thomis has written a sound documentation of this important historical movement in The Luddites: Machine-Breaking in Regency England.

4. See, for example, Sir Percy Snow, speaker, "Scientists and Decision Making," in Martin Greenberger, ed., Computers and the World of the Future, p. 5; and Langdon Winner, "Luddism as Epistemology," in Autonomous Technology, pp. 325-395.

5. Ben J. Wattenberg, ed., The Statistical History of the United States from Colonial Times to the Present.

6. U.S. Department of Commerce, Bureau of the Census, Statistical Abstract of the United States, 1986, 106th ed., p. 390; see also U.S. Bureau of the Census, How We Live: Then and Now.

7. Ben J. Wattenberg, ed., The Statistical History of the United States from Colonial Times to the Present.

8. U.S. Department of Commerce, Bureau of the Census, Statistical Abstract of the United States, 1986.

9. Ben J. Wattenberg, ed., The Statistical History of the United States from Colonial Times to the Present, p. 224.

10. U.S. Department of Commerce, Bureau of the Census, Historical Statistics of the U.S.: Colonial Times to 1970, vol. 1; and National Center for Education Statistics, U.S. Department of Education, 1986.

11. U.S. Department of Commerce, Bureau of the Census, Historical Statistics of the U.S.: Colonial Times to 1970, vol. 1.

12. U.S. Department of Commerce, Bureau of the Census, Historical Statistics of the U.S.: Colonial Times to 1970, vol. 1.

13. Wassily W. Leontief, The Impact of Automation on Employment 1963-2000.

14. Wassily W. Leontief, The Impact of Automation on Employment, 1963-2000.

15. This phenomenon is discussed at length by Barry Bluestone and Bennett Harrison, in The Deindustrialization of America; also, see Lester Thurow "The Surge in Inequality," Scientific American, May 1987, 30-38; and Harrison and Bluestone, The Great U-Turn.

16. Tom Forester surveys the cost and power trends in the computer revolution in High-Tech Society, pp.21-41.

17. Edward Feigenbaum and Pamela McCorduck discuss the impact of expert systems on the field of molecular biology in The Fifth Generation, p. 66. Sketches of computer-assisted diagnostic programs presently in use can be found in Katherine Davis Fishman, The Computer Establishment, pp. 361-366; see also Roger Schank, A Cognitive Computer: On Language, Learning, and Artificial intelligence, pp. 231-234.

18. Ben J. Wattenberg, ed., The Statistical History of the United States from Colonial Times to the Present, series F, pp. 1-5, 1965.

19. David L. Parnas delivers one perspective on this topic in "Computers in Weapons: The Limits of Confidence," in David Bellin and Gary Chapman, eds., Computers in Battle -Will They Work? pp. 209-231; also of interest is a statement on future prospects for AI by Robert Dale, in Allen M. Din, ed., Arms and Artificial Intelligence, p. 45.

20. This possibility may be more hypothetical than real because of the close relationship between manufacturing and services. Loss of manufacturing in key areas, for example, could be perilous to next-stage prospects for innovation. For an analysis of these and related problems, see S. S. Cohen and J. Zysman, Manufacturing Matters.

21. Translated from the Russian, "SAM" means surface-to-air missile, or literally, fixed maintenance depot to air.

22. See Tom Athanasiou, "Artificial Intelligence as Military Technology," in Bellin and Chapman, eds., Computers in Battle.

23. SCI is aimed toward the use of advanced computing to develop weapons and systems "for battle management in complex environments where human decision-making [isl seen to be inadequate" (Allan M. Din, ed., Arms and Artificial Intelligence, p. 7; see also pp. 90-91 in the same volume).

What Is AI, Anyway?

1. Similar definitions are found in many standard textbooks on AI.

2. This conference was originally called the Dartmouth Summer Research Project on Artificial Intelligence; for a full account of this landmark event, see Pamela McCorduck, Machines Who Think, pp. 93 ff.

3. Norbert Weiner, the famous mathematician who coined this term (later supplanted by the term "artificial intelligence"), was clearly fond of the meaning of its Greek root, "kubernetes": pilot or governor.

4. These terms were introduced by Edward Feigenbaum; see his "Art of Artificial Intelligence: Themes and Case Studies in Knowledge Engines," in AFIPS Conference Proceedings of the 1978 National Computer Conference 47: 227-240.

5. Roger Schank, The Cognitive Computer, pp. 49-51.

6. The layman may also want to see Susan J. Shepard, "Conversing with Tiny ELIZA," Computer Language 4 (May 1987). See also notes 61 and 62 to chapter 2.

7. See Hans Berliner, "New Hitech Computer Chess Success," AI Magazine 9 (Summer 1988): 133. And, for a brilliant discussion of machine versus human intelligence in chess and of dangers of rigidity in "learning machines," see Norbert Weiner, discussant, "Scientists and Decision Making," in Martin Greenberger, ed., Computers and the World of the Future, pp. 23-28.

8. See Lofti Zadeh, "Fuzzy Sets," in Information and Control8: 338-353. See also a fascinating interview with Zadeh published in Communications of the ACM, April 1984, pp. 304-311, in which he discusses the inadequacy of precise AI techniques and tools to solve real life ("fuzzy") problems.

9. See Sigmund Freud, The Psychopathology of Everyday Life, in The Basic Writings of Sigmund Freud; see also his Collected Papers; for another point of view, see Carl Jung et al., Man and His Symbols; and for a shorter but broad overview on the subject, see William Kessen and Emily D. Cahan, "A Century of Psychology: From Subject to Object to Agent," American Scientist, Nov.-Dec. 1986, pp. 640-650.

10. Newell's fullest and most current vision can be found in John E. Laird, A. Newell, and Paul S. Rosenbloom, "SOAR: An Architecture for Intelligence" (University of Michigan Cognitive Science and Machine Intelligence Laboratory Technical Report no. 2, 1987).

11. See Richard Dawkins's defense of Darwinism in The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe without Design; for some classic arguments on design versus necessity, also see A. Hunter Dupree, in Ada Gray, ed., Darwiniana, pp. 51-71.

12. This subject is eloquently addressed in a slim volume (23 pages) by S. Alexander, Art and Instinct.

13. To some, of course, the concept of God is not applicable to Buddhism; see William James, The Varieties of Religious Experience, pp. 42-44 and 315.

14. Charles Darwin, The Origin of the Species. In this, his classic work on natural selection and evolution, Darwin states, "If it could be demonstrated that any complex organ(ism) existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely breakdown" (p 229).

15. Richard Dawkins, The Blind Watchmaker, pp. 112-113.

16. Note, for example, a compelling argument against this notion (which instead champions the notion of hierarchy in evolution) in Stephen Jay Gould, "Is a New and General Theory of Evolution Emerging?" Paleobiology 6 (1979): 19-130.

17. See Gould, Paleobiology 6 (1979): 119-130. Also, in Stephen Jay Gould, The Mismeasure of Man, pp. 326-334, mention is made of "human nature" in relation to the concept of natural selection. See also Richard Dawkins, The Blind Watchmaker, pp. 141-142.

18. This idea is supported, at least in theory, by some pioneers of AI; see, for example, Lawrence Fogel, Alvin Owens, and Michael Walsh, Artificial Intelligence through Simulated Evolution, pp. viii and 112.

19. Edward Fredkin of MIT is credited with saying, "Artificial intelligence is the next step in evolution" in Sherry Turkle, The Second Self, p. 242.

Philosophical Roots

1. The literature on mind as machine is extensive. One provocative work is Daniel C. Dennett's Brainstorms: Philosophical Essays on Mind and Psychology. Dennett, a philosopher, draws upon the achievements of AI to formulate a new theory of mind. An important survey of philosophical issues can be found in Margaret Boden's Artificial Intelligence and Natural Man, chapter 14; see also Pamela McCorduck, Machines Who Think. A brief, useful summary of trends is the introduction ("Philosophy and AI: Some Issues") to Steve Torrance, ed., The Mind and the Machine: Philosophical Aspects of Artificial Intelligence. For the philosophy-AI nexus, see the papers in Martin D. Ringle, ed., Philosophical Perspectives in Artificial Intelligence. Another important source is John Haugeland, ed., Mind Design. The legacy of the mind-body problem is related to contemporary AI debates in succinct, lively fashion by Paul M. Churchland in Matter and Consciousness.

2. Some theorists who have argued for the mind-beyond-machine approach are J. R. Lucas, Hubert Dreyfus, and John Searle. Lucas, in 1961, used Gödel's incompleteness theorem to argue that computers could never model the human mind successfully; see his "Minds, Machines and Gödel," Philosophy 36 (1961): 120-124. For a refutation of this position, see Dennett's Brainstorms, chapter 13. Dreyfus's famous critique of AI is What Computers Can't Do: The Limits of Artificial Intelligence. Searle distinguishes between the capacities of "weak AI" and "strong AI" in his 1980 paper "Minds, Brains, and Programs," The Behavioral and Brain Sciences 3 (1980): 417-424. (Searle's paper is reprinted as chapter 10 of Haugeland's Mind Designs.) Here Searle introduces his famous "Chinese room" example to criticize what he sees as the "residual behaviorism" of AI. A particularly useful review of criticism of AI is J. Schwartz, "Limits of Artificial Intelligence," in Stuart C. Shapiro, ed., Encyclopedia of Artificial Intelligence, vol. 1. The Encyclopedia is an excellent general source.

3. See Boden's discussion, in Artificial Intelligence, pp. 21-63, of Colby's attempt to develop a computational model of human emotions; on pages 440-444 she argues that emotions are not "merely" feelings; in What Computers Can't Do, Dreyfus argues from a phenomenological standpoint that computers can never simulate our understanding, in part because of our capacity to experience emotions. Dennett provides an intriguing discussion of the matter in chapter 11 ("Why You Can't Make a Computer That Feels Pain") of Brainstorms.

4. According to Dreyfus in What Computers Can't Do, "The story of artificial intelligence might well begin around 450 B.C.," when Plato expressed the idea that "all knowledge must be stateable in explicit definitions which anyone could apply" (p. 67).

5. For an overview see D. A. Rees, "Platonism and the Platonic Tradition," The Encyclopedia of Philosophy, vol. 6, pp. 333-341 (New York: The Macmillan Company, 1967).

6. See Thomas L. Hankins, Science and the Enlightenment. See also Ernst Cassirer, The Philosophy of the Enlightenment; the first three chapters provide an important overview of the new studies of mind and how they reflected methods of the new science.

7. See Reinhardt Grossman, Phenomenology and Existentialism: An Introduction; the critiques of AI mounted by Hubert and Stuart Dreyfus have their roots in phenomenology. Hubert Dreyfus has developed the Heideggerian notion that understanding is embedded in a world of social purpose, which cannot be adequately represented as a set of facts. Stuart Dreyfus emphasizes the importance of skills that elude representations and rules by drawing upon the existential phenomenology of Merleau-Ponty. See H. Hall, "Phenomenology," in Shapiro, Encyclopedia of Artificial Intelligence, vol. 2, pp. 730-736.

8. See A. J. Ayer, "Editor's Introduction," in A. J. Ayer, ed., Logical Positivism, pp. 3-28; Rudolf Carnap, "The Elimination of Metaphysics through Logical Analysis of Language," in Ayer's Logical Positivism, pp. 3-81; Noam Chomsky, Syntactic Structures (1957). For a review of Chomsky's achievement and influence, see Frederick J. Newmeyer's Linguistic Theory in America, 2nd ed., chapter 2, "The Chomskyan Revolution."

9. This debate, in its technical and personal dimensions, is described in some detail in McCorduck's Machines Who Think.

10. Plato's works are readily available in Greek and English in the Loeb Classical Library editions; some other English translations of individual works are mentioned below. An excellent place to begin is any of several reference works: Gilbert Ryle, "Plato," in The Encyclopedia of Philosophy, vol. 6, pp. 324-333; D. J. Allan, "Plato," in The Dictionary of Scientific Biography, vol. 11, pp. 22-31 (New York: Charles Scribner's Sons, 1975). A more detailed account can be found in J. N. Findlay, Plato and Platonism: An Introduction.

11. In Aristotle: The Growth and Structure of His Thought, chapters 2 and 3, G. E. R. Lloyd describes Aristotle as both a pupil and a critic of Plato.

12. See "The Greek Academy," in The Encyclopedia of Philosophy, vol. 3, pp. 382-385. The Academy is also treated in Ryle's "Plato," pp. 317-319. In his excellent survey, A History of Greek Philosophy, vol. 4, p. 19, W. K. C. Guthrie explains that the Academy was by no means like our modern university: it had religious elements we might more readily associate with a medieval college. Volume 4 of this survey is devoted to Plato; the Academy is discussed on pp. 8-38. The early years of Plato's Academy are described in the reprint edition of Eduard Zeller's 1888 classic, Plato and the Older Academy. See note 17 below.

13. Guthrie (vol. 4, pp. 338-340) points out that Plato was influenced by the mystery religions of his day, especially in the Phaedo.

14. Plato describes the movements of the planets in important passages in the Republic and the Timaeus; In Plato's Timaeus, pp. 33-35, Francis Cornford provides a useful summary of the kinds of motion Plato describes in the Timaeus. G. E. R. Lloyd has a lucid and concise discussion of Plato's astronomy in chapter 7 of Early Greek Science: Thales to Aristotle, pp. 80-98. The nature of Plato's astronomy, long a controversial subject for the history of science, is analyzed in John D. Anton's Science and the Sciences in Plato.

15. The myth of Er in the Republic (617-618) was Plato's version of a scheme originally developed by the Pythagorean philosopher Philolaus, who put fire at the extremity and at the center of the universe, thus displacing the earth from its central position (G. S. Kirk, J. E. Raven, and M. Schofield, The Presocratic Philosophers, p. 259). The Pythagorean concept of a central fire is described by S. Sambursky in The Physical World of the Greeks, pp. 64-66.

16. The discovery of irrational numbers eventually resulted in the rejection of a Pythagorean "geometric atomism" and led to the concept of the continuum (S. Sambursky, The Physical World of the Greeks, pp. 33-35). In Plato's Theaetetus, the mathematician Theodorus demonstrates the irrationality of nonsquare numbers up to the root of 17. Plato then claims that the roots of all numbers that are not squares are irrational. According to G. E. R. Lloyd (Early Greek Science: Thales to Aristotle, pp. 32-34), the irrationality of the square root of 2 was known even before the time of Plato. The Greeks commonly expressed the proof in geometrical terms, by showing that the diagonal of a square is not commensurable with its side. (The proof assumes this commensurability, then shows that it leads to an impossibility because the resulting number is both odd and even.) The discovery that some magnitudes are incommensurable (c. 450-441 B.C.) is attributed to Hippacos of Mepontum, a member of the Pythagorean Brotherhood, in Alexander Helleman and Bryan Bunch, The Timetables of Science, p. 31.

17. E. R. Dodds, The Greeks and the Irrational is a classic treatment of this subject. Ananke is described in detail in F. M. Cornford, Plato's Cosmology, pp. 159-177. A more recent work is Richard R Mohr's Platonic Cosmology.

18. In the Phaedo and The Republic, Plato opposes the activity of intellect to the "brutish" passivity of desire (Martha Nussbaum, "Rational Animals and the Explanation of Action," in The Fragility of Goodness: Luck and Ethics in Greek Tragedy and Philosophy, p. 273). In this book Nussbaum explores the antithesis in Greek philosophy between the controlling power of reason and events beyond one's control, an antithesis central to Plato's dialogues.

19. The first mention of the Forms is in the Phaedo; an excellent discussion can be found in Gilbert Ryle's article (pp. 320-324) in The Encyclopedia of Philosophy.

20. Plato's theory of matter in the Timaeus, where the smallest particles are triangles, is a blend of Pythagorean ideas and Democritan atomism (see S. Sambursky, The Physical World of the Greeks, p. 31).

21. Cornford, in Plato's Cosmology, pp. 159-177, provides a lucid discussion of this tension between necessity and reason.

22. On the dialog as Plato's chosen form, see D. Hyland's "Why Plato Wrote Dialogues," Philosophy and Rhetoric 1 (1968): 38-50.

23. Physicist Werner Heisenberg describes how he arrived at his uncertainty principle, which he formulated in 1927 in chapter 6 of his gracefully written and entertaining volume Physics and Beyond: Encounters and Conversations. Heisenberg was influenced by Plato's corpuscular physics, and he explores the relation between Plato's ideas and quantum theory in chapter 20, "Elementary Particles and Platonic Philosophy (1961-1965)."

24. A refreshing new interpretation of the Phaedrus emphasizing the role of paradox is Martha Nussbaum's "'This Story Isn't True': Madness, Reason, and Recantation in the Phaedrus," chapter 7 in The Fragility of Goodness, pp. 200-228.

25. D. A. Rees, "Platonism and the Platonic Tradition," p. 336. It was Xenocrates, who headed the Academy after the death of Speusippus, Plato's immediate successor, who identified the Platonic Ideas with mathematical numbers, not the "ideal" numbers postulated in the Academy under Plato and discussed in the Phaedo. The fates of the various forms of Platonism are reviewed in several brief articles in the Dictionary of the History of Ideas (New York: Charles Scribner's Sons, 1973), vol. 3: John Fisher's "Platonism in Philosophy and Poetry," pp. 502-508; John Charles Nelson's "Platonism in the Renaissance," pp. 508-515; and Ernst Moritz Manasse's "Platonism since the Enlightenment," pp. 515-525.

26. D. H. Fowler, in The Mathematics of Plato's Academy, reconstructs in detail the curriculum of the Academy. A particularly readable account of the work of the geometers can be found in chapter 3 of Francois Lasserre, The Birth of Mathematics in the Age of Plato. A more technical treatment can be found in chapter 3 of Wilbur Richard Knorr, The Ancient Tradition of Geometric Problems.

27. For a general overview of Plato's philosophy of numbers, see "Plato," The New Encyclopedia Britannica, vol. 14, p. 538. For the text of the Epinomis in Greek and English, see W. R. M. Lamb, ed., Plato, Loeb Classical Library, vol. 8. In the Epinomis, 976 D-E, the speaker asks what science is indispensable to wisdom: "it is the science which gave number to the whole race of mortals." See also R. S. Brumbaugh, Plato's Mathematical Imagination.

28. A superb introduction to Enlightenment thought is Peter Gay's two volumes, The Enlightenment: An Interpretation, vol. 1, The Rise of Modern Paganism and vol. 2, The Science of Freedom.

29. The definitive biography is Richard Westfall's Never at Rest: A Biography of Isaac Newton. No one interested in Isaac Newton's scientific achievement should fail to see I. Bernard Cohen's Newtonian Revolution. Those who wish to tackle Newton in the original should see Isaac Newton's Philosophiae Naturalis Principia Mathematica, 3rd edition (1726), assembled by Alexander Koyré, I. Bernard Cohen, and Anne Whitman.

30. Otto Mayr, Authority, Liberty, and Automatic Machinery in Early Modern Europe.

31. A useful overview of Descartes's life and work can be found in The Dictionary of Scientific Biography, vol. 4, pp. 55-65. Descartes, by Jonathan Rée, is unsurpassed in giving a unified view of Descartes's philosophy and its relation to other systems of thought.

32. The brief Discours de la Méthode appeared in 1637 and is written in a lively autobiographical manner. It is readily available in the Library of the Liberal Arts edition, which includes the appendixes in which Descartes introduced analytic geometry and his theory of refraction: Discourse on Method, Optics, Geometry, and Meteorology, trans. by Paul J. Olscamp.

33. Derek J. de Solla Price, "Automata and the Origins of Mechanism and Mechanistic Philosophy," Technology and Culture 5 (1964): 23.

34. See I. Bernard Cohen on Newton in the Dictionary of Scientific Biography, vol. 10, pp. 42-103, and Cohen's Newtonian Revolution, mentioned above.

35. Charles Gillispie, The Edge of Objectivity, p. 140. The resulting prestige of science during the Enlightenment is treated in chapter 5.

36. For a readable and lucid introduction to relativity, see the 1925 classic by Bertrand Russell, The ABC of Relativity, 4th rev. ed. A more detailed treatment may be found in Albert Einstein, Relativity: The Special and General Theory, a Popular Exposition, trans. Robert Lawson.

37. Gillispie, The Edge of Objectivity, pp. 145-150.

38. Leibniz's criticism of the watchmaker God can be found in a letter written in November 1715 to Samuel Clarke (1675-1729), a renowned disciple of Newton (see pp. 205-206 of Leibniz's Philosophical Writings, G. H. R. Parkinson, ed.). For the famous debate this letter initiated, see The Leibniz-Clarke Correspondence, H. G. Alexander, ed.

39. W. T. Jones, Kant and the Nineteenth Century, p. 14. The legacy of Descartes is expressed in Kant's own definition of the Enlightenment, which is quoted by Ernst Cassirer in The Philosophy of the Enlightenment, p. 163: "Enlightenment is man's exodus from his self-incurred tutelage. Tutelage is the inability to use one's understanding without the guidance of another person. This tutelage is self-incurred if its cause lies not in any weakness of the understanding, but in indecision and lack of courage to use the mind without the guidance of another. 'Dare to know' (sapere aude)! Have the courage to use your own understanding; this is the motto of the Enlightenment."

40. Immanuel Kant, Critique of Pure Reason, 1st ed. 1781; Prolegomena to Any Future Metaphysics, 1st ed. 1783. The relations between Kantian philosophy and science are explored in Gordon G. Brittan, Jr., Kant's Theory of Science.

41. A brief history of logical positivism can be found in A. J. Ayer, Logical Positivism, pp. 3-28. Moritz Schlick, center of the Vienna Circle in the 1920s, compares the Kantian and positivist treatments of reality in "Positivism and Realism," an essay published in 1932 or 1933 and reprinted in Ayer's Logical Positivism (see p. 97).

42. Ayer, in Logical Positivism, p. 11, points out the positivist nature of Hume's attack on metaphysics and then claims that he could well have cited Kant instead, "who maintained that human understanding lost itself in contradictions when it ventured beyond the bounds of possible experience." Ayer claims that "the originality of the logical positivists lay in their making the impossibility of metaphysics depend not upon the nature of what could be known but upon the nature of what could be said" (Logical Positivism, p. 11).

43. Norman Malcolm, Ludwig Wittgenstein: A Memoir, with a Biographical Sketch by Georg Henrik Von Wright, p. 10. Whereas Kant distinguished between what can and cannot be known, Wittgenstein distinguished between what can and cannot be said. See "The Tractatus," chapter 6 of W. T. Jones, The Twentieth Century to Wittgenstein and Sartre.

44. Ludwig Wittgenstein, Tractatus Logico-Philosophicus, trans. by D. F. Pears and B. F. McGuiness, first German edition published in 1921.

45. Malcolm, Ludwig Wittgenstein, pp. 11-12.

46. Wittgenstein, Tractatus, p. 37.

47. Wittgenstein, Tractatus, p. 115.

48. Wittgenstein, Tractatus, p. 115.

49. For a readable discussion of the Church-Turing thesis, see David Harel's Algorithmics: The Spirit of Computing, pp. 221-223. The Church-Turing thesis, named after Alonzo Church and Alan Turing, is based on ideas developed in the following papers: Alan Turing, "On Computable Numbers with an Application to the Entscheidungsproblem," Proc. London Math. Soc. 42(1936): 230-265; Alonzo Church, "An Unsolvable Problem of Elementary Number Theory," Amer. J. Math. 58 (1936): 345-363.

50. See, for example, statement 4.002 in Wittgenstein's Tractatus, p. 37.

51. Wittgenstein, Tractatus, pp. 7, 151.

52. Ludwig Wittgenstein, Philosophical Investigations, trans. G .E .M. Anscombe.

53. Michael Dummett, in his "Frege and Wittgenstein" (in Irving Block, ed., Perspectives on the Philosophy of Wittgenstein, pp. 31-42), argues that Wittgenstein tried and failed to provide a theory of language in Philosophical Investigations.

54. In the preface to Philosophical Investigations (p. vi), Wittgenstein claims that he recognized "grave mistakes" in his earlier work, the Tractatus. The more atomistic approach of the latter is challenged by a greater emphasis on contexts in Philosophical Investigations. Anthony Kenny compares the two works in "Wittgenstein's Early Philosophy of Mind," Block, ed., Perspectives, pp. 140-147. A. J. Ayer remarks that Wittgenstein "modified the rigors of his early positivism" as expressed in the Tractatus. (See Ayer's Logical Positivism, p. 5).

55. In the Preface to his 1936 work Language, Truth and Logic, p. 31, Alfred Ayer asserts that his views stem from the writings of Russell and Wittgenstein.

56. See Reinhardt Grossman, Phenomenology and Existentialism.

57. Tractatus, p. 151.

58. Hubert L. Dreyfus, "Alchemy and Artificial Intelligence," The RAND Corporation, December 1965, publication 3244. For a profile of Dreyfus, see Frank Rose, "The Black Knight of AI," Science 85, 6 (March 1985): 46-51.

59. Pamela McCorduck, Machines Who Think, p. 204. McCorduck devotes chapter 9 ("L'Affair Dreyfus") to an engaging history of Dreyfus's critique and the reactions it provoked in the AI community.

60. ELIZA was first announced in Joseph Weizenbaum's "ELIZA-A Computer Program for the Study of Natural Language Communication between Man and Machine," Communications of the Association for Computing Machinery 9 (1966): 36-45. Hubert Dreyfus stumped ELIZA by entering the phrase "I'm feeling happy," and then correcting it, by adding "No, elated." ELIZA responded with "Don't be so negative," because it is programmed to respond that way whenever "no" appears anywhere in the input. See Hubert Dreyfus and Stuart Dreyfus, "Why Computers May Never Think like People," Technology Review 89 (1986): 42-61.

61. ELIZA mimics a Rogerian psychotherapist, whose technique consists largely of echoing utterances of the patient; it therefore uses very little memory, and arrives at its "answers" by combining transformations of the "input" sentences with phrases stored under keywords. Its profound limitations were acknowledged by its creator. In his 1976 work, Computer Power and Human Reason, Weizenbaum argues that ELIZA's limitations serve to illustrate the importance of context for natural language understanding, a point made in his original paper. He chose this kind of psychotherapeutic dialog precisely because the psychotherapist in such a dialog need know practically nothing about the real world. See Margaret Boden, Artificial Intelligence and Natural Man, p. 108.

62. Dreyfus developed this argument in detail in What Computers Can't Do: The Limits of Artificial Intelligence. There he sets out objections to "the assumption that man functions like a general-purpose symbol-manipulating device" (p. 156). Especially drawing his ire was the work of Allen Newell and H. A. Simon, Computer Simulation of Human Thinking, The RAND Corporation, P-2276 (April 1961).

63. PROLOG, a language based upon logic programming, was devised by Colmerauer at Marseille around 1970 (see W. F. Clocksin and C. S. Mellish, Programming in PROLOG).

64. Fuzzy logic, developed by L. A. Zadeh, guards against the oversimplification of reality by not assuming all fundamental questions have yes or no answers. See E. H. Mamdani and B. R. Gaines, Fuzzy Reasoning and Its Applications.

65. See, in particular, the introduction to the revised edition, in Hubert Dreyfus, What Computers Can't Do.

66. Dreyfus's predictions about the limitations of chess-playing programs have been proven wrong time and again. Chess-playing programs have improved their performance through the application of greater and greater computational power. One of the latest benchmarks occurred when HiTech won the Pennsylvania State Chess Championship in 1988. See Hans Berliner, "HITECH Becomes First Computer Senior Master," AI Magazine 9 (Fall 1988): 85-87.

67. McCorduck, Machines Who Think, p. 205.

68. In What Computers Can't Do Dreyfus argues, "There is no justification for the assumption that we first experience isolated facts, or snapshots of facts, or momentary views of snapshots of isolated facts, and then give them significance. The analytical superfluousness of such a process is what contemporary philosophers such as Heidegger and Wittgenstein are trying to point out" (p. 270).

69. Hubert L. Dreyfus and Stuart E. Dreyfus, "Making a Mind versus Modeling the Brain: Artificial Intelligence Back at a Branchpoint," Daedalus 117 (Winter 1988): 15-43. This issue of Daedalus, devoted to AI, was subsequently published in book form; see Stephen R. Graubard, ed., The Artificial Intelligence Debate: False Starts, Real Foundations.

70. Dreyfus and Dreyfus, "Making a Mind," p. 15.

71. Jack Cowan and David H. Sharp review the importance of neural nets for AI in "Neural Nets and Artificial Intelligence," Daedalus 117 (Winter 1988): 85-121.

72. Dreyfus and Dreyfus, "Making a Mind," pp. 38-39.

73. See "The Role of the Body in Intelligent Behavior," chapter 7 of Hubert Dreyfus's What Computers Can't Do.

74. Sherry Turkle also explores children's responses to computers in her 1984 work, The Second Self: Computers and the Human Spirit, chapter 1, "Child Philosophers: Are Smart Machines Alive?"

75. Sigmund Freud, Jokes and Their Relation to the Unconscious, 1st ed, 1905. Marvin Minsky provides a new interpretation of jokes, emphasizing the importance of "knowledge about knowledge," in his "Jokes and the Logic of the Cognitive Unconscious," in Lucia Vaina and Jaakko Hintikka, eds., Cognitive Constraints on Communication, pp. 175-200.

Mathematical Roots

1. For the relationship between logic and recursion, see Stephen Cole Kleene, "I-Definability and Recursiveness," Duke Mathematical Journal2 (1936): 340-353. See also Stephen Cole Kleene, Introduction to Metamathematics. For Rosser's contribution, see J. Barkley Rosser, "Extensions of Some Theorems of Gödel and Church," Journal of Symbolic Logic 1 (1936): 87-91. Church has made many important contributions to logic and computation. A coherent presentation of his work appears in Alonzo Church, Introduction to Mathematical Logic, vol. 1.

2. For the flavor of this theory, see a classic text on numerical analysis and computation: R. W. Hamming, Introduction to Applied Numerical Analysis.

3. A good example of such thinking is Bertrand Russell, Introduction to Mathematical Philosophy.

4. The paradox was first introduced in Bertrand Russell, Principles of Mathematics, 2nd ed., pp 79-81. Russell's paradox is a subtle variant of the Liar Paradox. See E. W. Beth, Foundations of Mathematics, p. 485.

5. Gottlob Frege was about to publish a monumental work on arithmetic and set theory when Russell pointed out the implications of his paradox. Frege could only add a postscript that said, "A scientist can hardly meet with anything more undesirable than to have the foundations give way just as the work is finished. In this position I was put by a letter from Mr. Bertrand Russell." See Bertrand Russell, Letter to Frege, 1902, published in Jean van Heijenoort, ed., From Frege to Gödel.

6. Bertrand Russell, Principles of Mathematics, 2nd ed., 1938, pp. 10-32, 66-81.

7. Bertrand Russell, Principles of Mathematics, 2nd ed., pp. 10-32, 66-81.

8. See Bertrand Russell, Principles of Mathematics, 2nd ed., pp. v-xiv.

9. See also Alfred N. Whitehead and Bertrand Russell, Principia Mathematica, 3 vols., 2nd ed., pp. 187-231.

10. First introduced in Alan M Turing, "On Computable Numbers with an Application to the Entscheidungsproblem," Proc. London Math. Soc. 42 (1936): 230-265.

11. Work on PROLOG began in 1970. A clear presentation of the conceptual foundations of PROLOG appears in Robert Kowalski, "Predicate Logic as a Programming Language," University of Edinburgh, DAI Memo 70, 1973. See also Alain Colmerauer, "Sur les bases théoriques de Prolog," Groupe de IA, UER Luminy, Univ. d'Aix-Marseilles, 1979. This and other aspects of the Japanese program are discussed in Edward Feigenbaum and Pamela McCorduck, The Fifth Generation, p. 115.

12. These early experiments are described in A. Newell, J. C. Shaw, and H. Simon, "Empirical Explorations with the Logic Theory Machine," Proceedings of the Western Joint Computer Conference 15 (1957): 218-239.

13. Turing's theoretical model was first introduced in Alan M. Turing, "On Computable Numbers with an Application to the Entscheidungsproblem," Proc. London Math. Soc." 42 (1936): 230-265.

14. An enormously influential paper is Alan M. Turing, "Computing Machinery and Intelligence," Mind 59 (1950): 433-460, reprinted in E. Feigenbaum and J. Feldman, eds., Computers and Thought.

15. The program is called the "Turochamp" (evidently a contraction of "Turing and Champernowne"). See Andrew Hodges, Alan Turing: The Enigma, pp. 338-339.

16. Turing researched morphogenesis deeply enough to produce a paper on the subject: Alan M. Turing, "The Chemical Basis of Morphogenesis," Phil. Trans. Roy. Soc. 1952: B237.

17. See Andrew Hodges, Alan Turing: The Enigma, pp. 267-268.

18. For an engineering account of this project, see B. Randell, "The Colossus" (1976), reprinted in N. Metropolis, J. Howlett, and G. C. Rota, eds., A History of Computing in the Twentieth Century.

19. See David Hilbert, Grundlagen der Geometrie, Liepzig and Berlin, 1899, 7th ed., 1930.

20. Alan M. Turing. "On Computable Numbers with an Application to the Entscheidungsproblem," Proc. London Math. Soc. 42 (1936): 230-265.

21. Simpler models that have appeared since have perhaps been ignored. See Marvin Minsky, Computation: Finite and Infinite Machines.

22. This thesis was independently arrived at by both Church and Turing around 1936.

23. For an excellent article on the theory of computation, see John M. Hopcroft, "Turing Machines," Scientific American, May 1984, pp. 86-98.

24. The busy beaver problem is one example of a large class of noncomputable functions, as one can see from Tibor Rado, "On Noncomputable Functions," Bell System Technical Journal4l, no. 3 (1962): 877-884.

25. Church's version of the result appears in Alonzo Church, "An Unsolvable Problem of Elementary Number Theory," American Jour. Math 58 (1936): 345-363.

26. We can see Gödel's concerns about Russell's framework in Kurt Gödel, "Russell's Mathematical Logic" (1944), in P. A. Schilpp, ed., The Philosophy of Bertrand Russell.

27. Gödel's incompleteness theorem first appeared in: Kurt Gödel, "Über formal unenscheiderbare Satze der Principia Mathematica und verwandter Systeme I," Monatsh. Math. Phys. 38 (1931): 173-198.

28. See Alonzo Church, "A Note on the Entscheidungsproblem," Journal of Symbolic Logic 1 (1936): 40-41, and Kurt Gödel, "On Undecidable Propositions of Formal Mathematical Systems," mimeographed report of lectures at the Institute for Advanced Study, Princeton, 1934.

29. Herbert A. Simon, The Shape of Automation for Men and Management (Harper & Row, 1965), p. 96.

30. A short reflection by Turing on some of the issues behind thinking machines appears as part of chapter 25 of B. W. Bowden, ed., Faster than Thought.

31. For an introductory account of some of the implications of the Church-Turing thesis, see Douglas Hofstadter, Gödel, Escher, Bach: An Eternal Golden Braid, pp. 559-586.

The Formula for Intelligence

1. See Morris Kline, Mathematics and the Search for Knowledge.

2. See Albert Einstein, Relativity: The Special and the General Theory. A more readable account is presented in Bertrand Russell, ABC of Relativity See also A. Einstein, "Zur Elektrodynamic bewegter Korpen," Annalen der Physik 17 (1905): 895, 905.

3. For the mathematically mature, an excellent introduction can be found in Enrico Fermi, Thermodynamics (Englewood Cliffs, N.J.: Prentice-Hall, 1937).

4. Atkins gives an account of thermodynamics and entropy that is fascinating and informal yet scholarly in P. W. Atkins, The Second Law.

5. A glimpse into the complexity is presented in Allan C. Wilson, "The Molecular Basis of Evolution," Scientific American, October 1985, pp. 164-173.

6. See Rudy Rucker, The Five Levels of Mathematical Reality, pp. 14-35.

7. The motivations and quests for anthropomorphic parallels are considered in John D. Barrow and Frank J. Tipler, The Anthropic Cosmological Principle, pp. 1-23.

8. See Robert P. Crease and Charles C. Mann, The Second Creation, pp. 393-420.

9. For one contribution to a "theory of everything," see Stephen Hawking, A Brief History of Time. A more popular discussion is given in Heinz R. Pagels, Perfect Symmetry, pp. 269-367.

10. In 1666 Gottfried Leibniz contemplated a scientific system of reasoning, the "calculus ratiocinator," that could be used to settle arguments formally. George Boole took up this problem and presented his work in 1854 in An Investigation of the Laws of Thought on Which Are Founded the Mathematical Theories of Logic and Probabilities, aspects of which are discussed in the next few pages

11. See Douglas Hofstadter, Gödel, Escher, Bach. An Eternal Golden Braid, pp. 559-586.

12. Meindl, James D. "Chips for Advanced Computing," Scientific American, October 1987, p. 78.

13. For a detailed treatment, see Carver Mead and Lynn Conway, Introduction to VLSI Systems. Old but nonetheless broadly relevant is the article Ivan E. Sutherland and Carver A. Mead, "Microelectronics and Computer Science," Scientific American, September 1977, pp. 210-228.

14. For a discussion that is less philosophical than that of Hofstadter, see Rudy Rucker, The Five Levels of Mathematical Reality, pp. 207-249.

15. See John M. Hopcroft, "Turing Machines," Scientific American, May 1984, p. 91.

16. See A. Newell and H. A. Simon, "GPS: A Program that Simulates Human Thought," in E. A. Feigenbaum and J. Feldman, eds., Computers and Thought, pp. 71-105, and Claude Shannon, "A Chess Playing Machine," Scientific American, October 1950.

17. For a sketch, see Patrick H. Winston, "The LISP Revolution, " BYTE, April 1985, p. 209.

18. For this reason we've been more successful in building checkers programs. See Arthur L. Samuel, "Some Studies in Machine Learning Using the Game of Checkers," (1959), reprinted in E. A. Feigenbaum and J. Feldman, eds., Computers and Thought, pp. 279-293. An early note is given in Claude Shannon, "Programming a Computer for Playing Chess," Philosophical Magazine, series 7, 41 (1950): 256-275.

19. This and some of the other formulations discussed here have been examined in depth by researchers in game theory. A seminal work in the area is R. D. Luce and H. Raiffa, Games and Decisions. The famous Minimax theorem itself was presented in J. von Neumann, "Zur Theorie der Gesellschaftespiele," Mathematische Annalen 100 (1928): 295-320.

20. This serves to show that in theory a computer can be as good as any human chess player.

21. Researchers have tried various strategies to get around the problems created by this combinatorial explosion in the number of possible chess moves at each stage. See Peter Frey, "An Introduction to Computer Chess," in Peter Frey, ed., Chess Skill in Man and Machine, and also M. M. Botvinnik, Computers in Chess, pp. 15-21.

22. A. K. Dewdney, "The King Is Dead, Long Live the King," Scientific American, May 1986, p. 13.

23. See Gregory Chaitin, "On the Difficulty of Computation," IEEE Transactions on Information Theory 16 (1970): 5-9, and Gregory Chaitin, "Computing the Busy Beaver Function," IBM Watson Research Center Report, RC 10722, 1970. An easy introduction to certain aspects of computability and complexity is in Michael R. Garey and David S. Johnson, Computers and Intractability.

24. See, for instance, the piece by M. A. Tsasfman and B. M. Stilman in M. M. Botvinnik, ed., Computers in Chess. Also see Carl Ebeling, All the Right Moves, pp. 56-64.

25. A lucid presentation on the two positions can be found in Carl Ebeling, All the Right Moves, pp, 1-3.

26. Compare the various strategies and systems described in Peter Frey, ed., Chess Skill in Man and Machine.

27. A recent report on HiTech is Hans Berliner, AI Magazine, Summer 1988.

28. The structure of HiTech is well documented in Carl Ebeling, All the Right Moves.

29. H. A. Simon and Allen Newell, "Heuristic Problem Solving: The Next Advance in Operations Research," Operations Research 6 (January-February 1958).

30. A report of the system's performance is given in Danny Kopec and Monty Newborn, "Belle and Mephisto Dallas Capture Computer Chess Titles at the FJCC," Communications of the ACM, July 1987, pp. 640-645.

31. In 1988 HiTech became the first system to beat a human chess grandmaster, albeit one who has been out of form. See Harold C. Schonberg, New York Times, September 26, 1988.

32. See W. Daniel Hillis, "The Connection Machine," Scientific American, June 1987.

33. Eliot Hearst, "Man and Machine: Chess Achievements and Chess Thinking," in Peter Frey, ed., Chess Skill in Man and Machine.

34. A useful examination of the psychology of chess-playing in the light of the performance of chess programs is given in Brad Leithauser, "Computer Chess," New Yorker, May 9, 1987, pp. 41-73. See also the article by Hearst, cited in note 33.

35. An excellent survey is in Geoffrey C. Fox and Paul C. Messina, "Advanced Computer Architectures," Scientific American, October 1987, pp. 66-74. The flurry of research activity is evident from Richard Miller (project manager), Optical Computers: The Next Frontier in Computing, vols.1 and 2 (Englewood, N.J.: Technical Insights, 1986).

36. Even the early checkers programs were quite good. See Pamela McCorduck, Machines Who Think, pp.152-153.

37. H. J. Berliner, "Backgammon Computer Program Beats World Champion," Artificial Intelligence 14, no.1 (1980).

38. See H. J. Berliner, "Computer Backgammon," Scientific American, June 1980.

39. The number of possible moves at each point is estimated at 200 for go. See E. Thorp and W. E. Walden, "A Computer-Assisted Study of Go on M by N Boards," in R. B. Banerji and M. D. Mesarovic, eds., Theoretical Approaches to Non-numerical Problem-Solving (Berlin: Springer-Verlag, 1970), pp. 303-343.

40. An early effort on go is described in W. Reitman and B Wilcox, "Pattern Recognition and Pattern Directed Inference in a Program for Playing Go," in D. A. Waterman and F. Hayes-Roth, eds., Pattern-Directed Inference Systems.

41. As stated by John Laird, the cannibals and missionaries problem is, "Three cannibals and three missionaries want to cross a river. Though they can all row, they only have available a small boat that can hold two people. The difficulty is that the cannibals are unreliable: if they ever outnumber the missionaries on a river bank, they will kill them. How do they manage the boat trips so that all six get safely to the other side?"

42. A. Newell, J. C. Shaw, and H. A. Simon, "Empirical Explorations with the Logic Theory Machine" (1957), reprinted in E. A. Feigenbaum and J. Feldman, eds., Computers and Thought, pp. 109-133. The generalized results can be seen in A. Newell, J. C. Shaw and H. A. Simon, "A Report on a General Problem Solving Program," Proceedings of the International Conference on Information Processing (UNESCO, Paris, 1959), pp. 256-264.

43. Notably from the Dreyfus brothers. See Hubert Dreyfus, What Computers Can't Do, 2nd ed.

44. A. Newell and H. A. Simon, "GPS: A Program That Simulates Human Thought," in E. A. Feigenbaum and J. Feldman, eds., Computers and Thought, pp. 71-105.

45. H. A. Simon and Allen Newell, "Heuristic Problem Solving: The Next Advance in Operations Research," Operations Research. 6 (January-February 1958).

46. Some problems are described in Patrick H. Winston, Artificial Intelligence, pp. 146-154. The results and lessons of GPS are detailed in A. Newell and H. A. Simon, Human Problem Solving.

47. See E. Feigenbaum and Avron Barr, The Handbook of Artificial Intelligence, vol. 1, pp. 123-138.

48. An excellent paper on intelligence and computer chess is A. Newell, J. C. Shaw, and H. A. Simon, "Chess Playing Programs and the Problem of Complexity" (1958), reprinted in E. Feigenbaum and J. Feldman, Computers and Thought

49. Minsky's views on intelligence serve us well here: Marvin Minsky, "Why People Think Computers Can't," Technology Review, November-December 1983, pp. 64-70.

50. Formally defined in Marvin Minsky and Seymour Papert, Perceptrons, p. 12.

51. W. S. McCulloch and W. Pitts, "A Logical Calculus of the Ideas Immanent in Neural Nets," Bulletin of the Mathematical Biophysics 5 (1943).

52. Marvin Minsky and Seymour Papert, Perceptrons, pp. 136-150.

53. An excellent introductory article on the history and achievements of connectionism is Jerome Feldman, "Connections," BYTE, April 1985, pp. 277-284.

54. This is reflected in the progress reports issued by the MIT AI Laboratory during that period. See, for instance, Marvin Minsky, Seymour Papert, "New Progress in Artificial Intelligence," MIT Artificial Intelligence Laboratory, AI memo 252, 1972.

55. See Douglas Hofstadter, Metamagical Themas, pp. 274-292.

56. Widely applicable algorithms are likely to perform weakly in all their domains. See Seymour Papert, "One AI or Many," Daedalus, Winter 1988.

57. A recent survey is in Jack D. Cowan and David. H. Sharp, "Neural Nets and Artificial Intelligence," Daedalus, Winter 1988, pp. 85-121.

58. Important papers on recent work are put together in the standard reference in the field: D. E. Rumelhart, J. L. McClelland, and the PDP Research Group, Parallel Distributed Processing.

59. See Marvin Minsky, "Connectionist Models and Their Prospects," in David Waltz, ed., Connectionist Models and Their Implications (Norwood, N.J.: Ablex Publishing, 1988).

60. This selection is carried out in the style of "summarizing" in the society theory. See Marvin Minsky, Society of Mind, p. 95.

61. Decision trees have been used extensively in Management Science. For an enjoyable introduction, see Howard Raiffa, Decision Analysis: Introductory Lectures (Reading, Mass.: Addison-Wesley).

62. This is a point well brought out in Marvin Minsky, "Why People Think Computers Can't," Technology Review, November-December 1983, pp. 64-70.

63. See R. C. Schank and R. Abelson, Scripts, Plans, Goals, and Understanding (Hillsdale, N.J.: Erlbaum, Lawrence Associates, 1977).

64. Marvin Minsky, "Plain Talk about Neurodevelopment Epistemology," Proceedings of the Fifth International Joint Conference on AI (Cambridge, Mass., 1977). Minsky's work culminated in a major book: Marvin Minsky, The Society of Mind.

65. Minsky, The Society of Mind, p. 17.

66. For a sketch of the society theory, see Marvin Minsky, "Society of Mind," Artificial Intelligence Journal 1989.

67. For early related work, see Jerome Lettvin, H. Maturana, W. McCulloch and W. Pitts, "What the Frog's Eye Tells the Frog's Brain," Proceedings of the IRE 47 (1959): 1940-1951. This famous paper is reprinted with other related papers in Warren S. McCulloch, Embodiments of Mind. Also see: W. S. McCulloch and W. Pitts, "A Logical Calculus of the Ideas Immanent in Neural Nets," Bulletin of the Mathematical Biophysics 5 (1943), reprinted in Warren S. McCulloch, Embodiments of Mind.

68. Jerome Lettvin, H. Maturana, W. McCulloch and W. Pitts, "What the Frog's Eye Tells the Frog's Brain," Proceedings of the IRE 47 (1959): 1940-1951.

69. John McDermott, "R1: A Rule-Based Configurer of Computer Systems," Artificial Intelligence 19, no. 1 (1982). Also see John McDermott, "XSEL: A Computer Salesperson's Assistant," in J. Hayes, D. Michie, and Y. H. Pao, Machine Intelligence 10(New York: Halsted, Wiley, 1982).

70. P. H. Winston and K. A. Prendergast, eds., The AI Business, pp. 41-49, 92-99.

71. A strong case for the use of computers largely as office environment shapers is in Terry Winograd and Fernando Flores, Understanding Computers and Cognition: A New Foundation for Design.

72. See Seymour Papert, "One AI or Many?" Daedalus, Winter 1988, p. 7.

73. One large-scale effort that takes this problem seriously is described in D. Lenat, M. Shepherd, and M. Prakash, "CYC: Using Common Sense Knowledge to Overcome Brittleness and Knowledge Acquisition Bottlenecks," AI Magazine, Winter 1986.

74. An enjoyable account of genetics, evolution, and intelligence is in Carl Sagan, The Dragons of Eden.

75. The original reports of Crick and Watson, surprisingly readable, may be found in James A. Peters, ed., Classic Papers in Genetics (Englewood Cliffs, N.J.: Prentice-Hall, 1959). An exciting account of the successes and failures that led to the double helix is given in J. D. Watson, The Double Helix.

76. The structure and behavior of DNA and RNA are described in: Felsenfeld Gary, "DNA," Scientific American, October 1985. And: James Darnell, "RNA," Scientific American, October 1985.

77. A fascinating account of the new biology is given in Horace F. Judson, The Eighth Day of Creation.

78. G. L. Stebbins and F. J. Ayala, "The Evolution of Darwinism," Scientific American, July 1985, p. 73.

Mechanical Roots

1. See J. David Bolter, Turing's Man: Western Culture in the Computer Age, pp. 17-24. Bolter illustrates the mechanism for astronomical calculation described in detail in Derek J. de Solla Price, "An Ancient Greek Computer," Scientific American, June 1959, pp. 60-67; see also Derek J. de Solla Price, Gears from the Greeks: The Antikythera Mechanism -A Calendar Computer from circa 80 B.C. Early automata and their relation to AI are discussed in Pamela McCorduck's popular 1979 history of AI research, Machines Who Think, chapter 1. Another useful and lively source is John Cohen's Human Robots in Myth and Science. Perhaps the best detailed sources on automata through the ages are Derek J. de Solla Price, "Automata and the Origins of Mechanism and Mechanistic Philosophy," Technology and Culture 5 (1964): 9-23, and Silvio Bedini, "The Role of Automata in the History of Technology," Technology and Culture 5 (1964): 24-42. A classic volume with many illustrations is Alfred Chapuis and Edmond Droz, Automata: A Historical and Technological Study, trans. Alec Reid. Otto Mayr describes the significance of automata in European culture in Authority, Liberty, and Automatic Machinery in Early Modern Europe.

2. For a general history of the mechanical arts see C. Singer, E. J. Holmyard, A. R. Hall, and T. I. Williams, eds., A History of Technology, and A. P. Usher, A History of Mechanical Inventions, 2nd ed. Those interested in ancient technologies should consult R. J. Forbes, Studies in Ancient Technology.

3. Price, "Automata and the Origins of Mechanism," p. 11. Other important works on ancient technologies are A. G. Drachman, The Mechanical Technology of Greek and Roman Antiquity, A. P. Neuberger, The Technical Arts and Sciences of the Ancients, and K. D. White, Greek and Roman Technology.

4. Price, "Automata and the Origins of Mechanism," p. 11. Joseph Needham describes the fascinating automata in China at the time of the pre-Socratics in his Science and Civilisation in China, vol. 2, pp. 53-54, 516. The Chinese mechanical orchestra, consisting of twelve figures cast in bronze, is also described in Needham's Science and Civilisation in China., vol. 4, p. 158. Descartes, who was very interested in automata, described in one of his notebooks how to reproduce the pigeon of Archytas. See Mayr, Authority, Liberty, and Automatic Machinery, p. 63.

5. Far more on androids, see Samuel L. Macey, Clocks and the Cosmos: Time in Western Life and Thought; see also Carlo M. Cipolla, Clocks and Culture, 1300-1700, and David S. Landes, Revolution in Time: Clocks and the Making of the Modern World.

6. Bedini describes Torriano's automaton in "Automata in the History of Technology," p. 32, where it appears as figure 5. For more on P. Jacquet-Droz and Écrivain, see Bedini's "Automata," p. 39, and Macey's Clocks and the Cosmos, pp. 210-211. P. Jacquet-Droz's son, Henri-Louis, created a mechanical artist that drew flowers and a musician that played a clavecin. He also made a pair of artificial hands for a general's son, who had lost his own hands in a hunting accident. Henri-Louis's success in this venture was praised by the great creator of automata Jacques de Vaucanson (1709-1782). See the entries for Pierre-Jacquet Droz and Henri-Louis-Jacquet Droz in Nouvelle Biographie Générale, vol. 14 (Paris: Didot, 1868), pp. 812-813. Vaucanson was perhaps best known for his duck automaton, which ate, drank, chewed, and excreted. See Macey's Clocks and the Cosmos, p. 210, and Bedini's "Automata in the History of Technology," pp. 36-37, which has a diagram of the duck's inner mechanism (figures 11 and 12). Anyone interested in Vaucanson should see Michael Cardy, "Technology as Play: The Case of Vaucanson," Stud. Voltaire 18th Cent. 241 (1986): 109-123. In 1726 Jonathan Swift described a machine that would automatically write books; see Eric A. Weiss, "Jonathan Swift's Computing Machine," Annals of the History of Computing7 (1985): 164-165.

7. Martin Gardner, "The Abacus: Primitive but Effective Digital Computer," Scientific American 222 (1970): 124-127; Parry H. Moon, The Abacus: Its History, Its Design, Its Possibilities in the Modern World, J. M. Pullan, The History of the Abacus (London: Hutchinson, 1968).

8. Napier's bones or rods are described and pictured in Stan Augarten's Bit by Bit: An Illustrated History of Computers, pp. 9-10. A more detailed treatment can be found in M. R. Williams, "From Napier to Lucas: The Use of Napier's Bones in Calculating Instruments," Annals of the History of Computing 5 (1983): 279-296.

9. An earlier calculating machine was devised by the polymath Wilhelm Shickard (1592-1635). Shickard's machine, and Pascal's development of the Pascaline are described in Augarten's Bit by Bit: An Illustrated History of Computers, pp. 15-30. A more technical account can be found in René Taton,"Sur l'invention de la machine arithmetique," Revue d'histoire des sciences et de leurs applications 16 (1963): 139-160; Jeremy Bernstein, The Analytical Engine: Computers-Past, Present, and Future, p. 40; Herman Goldstine, The Computer from Pascal to von Neumann, p. 7-8.

10. Blaise Pascal, Pensées (New York: E. P. Dutton & Co., 1932), p. 96, no. 340.

11. The Pascaline, of which perhaps ten or fifteen were sold, failed to sell for a variety of reasons. See Augarten, Bit by Bit, pp. 27-30.

12. The Stepped Reckoner, as Leibniz called his machine, employed a special gear as a mechanical multiplier. See Augarten, Bit by Bit, pp. 30-35, and Goldstine, The Computer from Pascal to von Neumann, pp. 7-9. Morland's career is described in Henry W. Dickinson's biography, Sir Samuel Morland, Diplomat and Inventor, 1625-1695.

13. Brian Randell, ed., The Origins of Digital Computers: Selected Papers, p. 2.

14. Augarten, Bit by Bit, p. 89.

15. Babbage's paper can be found in H. P. Babbage, Babbage's Calculating Engines, pp. 220-222.

16. H. P. Babbage, Babbage's Calculating Engines, pp. 223-224. On Babbage and the Astronomical Society, see Anthony Hyman, Charles Babbage: Pioneer of the Computer, pp. 50-53.

17. See chapter 2 of Augarten's Bit by Bit, which has marvelous illustrations. Babbage's life and career are treated in detail in Hyman's Charles Babbage. Joel Shurkin provides a lively account of Babbage's work in his Engines of the Mind: A History of the Computer, chapter 2. A biography recently published almost a century after its completion is H. W. Buxton, Memoirs of the Life and Labours of the Late Charles Babbage, Esq., F.R.S., ed. A. Hyman.

18. Allen G. Bromley, Introduction to H. P. Babbage, Babbage's Calculating Engines, pp. xiii-xvi; Bernstein, The Analytical Engine, pp. 47-57.

19. Augarten, Bit by Bit, pp. 62-63; Bernstein, The Analytical Engine, p. 50; Hyman, Charles Babbage, p. 166.

20. Augarten, Bit by Bit, pp. 63-64. Babbage describes the features of his machine in "On the Mathematical Powers of the Calculating Engine," written in 1837 and reprinted as appendix B in Hyman's Charles Babbage.

21. A recent biography is Dorothy Stein, Ada, a Life and a Legacy.

22. Goldstine, The Computer, p. 26.

23. Her translation and notes can be found in H. P. Babbage, Babbage's Calculating Engines, pp. 1-50.

24. The lonely end of Babbage's life is described in Hyman, Charles Babbage, chapter 16.

25. Joel Shurkin, in Engines of the Mind, p. 104, describes Aiken's machine as "an electromechanical Analytical Engine with IBM card handling." For a concise history of the development of the Mark I, see Augarten's Bit by Bit, pp. 103-107. I. Bernard Cohen provides a new perspective on Aiken's relation to Babbage in his article "Babbage and Aiken," Annals of the History of Computing 10 (1988): 171-193.

26. Anyone with a serious interest in the history of calculators should be aware of the following two classics: D. Baxandall, Calculating Machines and Instruments, and Ellice Martin Horsburgh, ed., Modern Instruments and Methods of Calculation: A Handbook of the Napier Tercentenary Celebration Exhibition. Some of the calculators and tabulating machines of the 1940s are described in Charles and Ray Eames, A Computer Perspective, pp. 128-159. A brief pictorial history of calculating machines can be found in George C. Chase, "History of Mechanical Computing Machinery," Annals of the History of Computing 2 (1980): 198-226. Two important sources in the history of computing, besides the Annals, are N. Metropolis, J. Howlett, and Gian-Carlo Rota, eds., A History of Computing in the Twentieth Century, and Brian Randell, The Origins of Digital Computers.

27. See chapter 3 of Augarten's Bit by Bit, and Eames's A Computer Perspective, pp. 16-17, 22-30.

28. Augarten, Bit by Bit, pp. 78-83; Randell, Origins, p. 28.

29. Shurkin, Engines of the Mind, p. 94; Augarten, Bit by Bit, p. 82; Eames, A Computer Perspective, p. 39. Burroughs's life and work are described in Molly Gleiser, "William S. Burroughs," Computer Decisions, March 1978, pp. 34-36.

30. By 1913 the Burroughs Adding Machine Company had $8 million in sales, according to Augarten's Bit by Bit, p. 82.

31. The legacy of the census crisis is described in detail in L. E. Truesdell, The Development of Punch Card Tabulation in the Bureau of the Census, 1890-1940 (Washington D.C.: Government Printing Office, 1965).

32. See Geo