John McCarthy (September 4, 1927 – October 24, 2011) was an American

computer scientist A computer scientist is a person who is trained in the academic study of computer science. Computer scientists typically work on the theoretical side of computation, as opposed to the hardware side on which computer engineers mainly focus ( ...

and cognitive scientist. He was one of the founders of the discipline of

artificial intelligence Artificial intelligence (AI) is intelligence—perceiving, synthesizing, and inferring information—demonstrated by machine A machine is a physical system using Power (physics), power to apply Force, forces and control Motion, moveme ...

. He co-authored the document that coined the term "

" (AI), developed the

programming language A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language. The description of a programming l ...

family

Lisp A lisp is a speech impairment in which a person misarticulates sibilants (, , , , , , , ). These misarticulations often result in unclear speech. Types * A frontal lisp occurs when the tongue is placed anterior to the target. Interdental lispi ...

, significantly influenced the design of the language

ALGOL ALGOL (; short for "Algorithmic Language") is a family of imperative computer programming languages originally developed in 1958. ALGOL heavily influenced many other languages and was the standard method for algorithm description used by th ...

, popularized

time-sharing In computing, time-sharing is the sharing of a computing resource among many users at the same time by means of multiprogramming and multi-tasking.DEC Timesharing (1965), by Peter Clark, The DEC Professional, Volume 1, Number 1 Its emergence ...

, and invented garbage collection. McCarthy spent most of his career at Stanford University. He received many accolades and honors, such as the 1971

Turing Award The ACM A. M. Turing Award is an annual prize given by the Association for Computing Machinery (ACM) for contributions of lasting and major technical importance to computer science. It is generally recognized as the highest distinction in compu ...

for his contributions to the topic of AI, the United States

National Medal of Science The National Medal of Science is an honor bestowed by the President of the United States to individuals in science and engineering who have made important contributions to the advancement of knowledge in the fields of behavioral and social scienc ...

, and the Kyoto Prize.

Early life and education

John McCarthy was born in Boston, Massachusetts, on September 4, 1927, to an Irish immigrant father and a

Lithuanian Jewish Lithuanian Jews or Litvaks () are Jews with roots in the territory of the former Grand Duchy of Lithuania (covering present-day Lithuania, Belarus, Latvia, the northeastern Suwałki and Białystok regions of Poland, as well as adjacent areas ...

immigrant mother, John Patrick and Ida (Glatt) McCarthy. The family was obliged to relocate frequently during the Great Depression, until McCarthy's father found work as an organizer for the

Amalgamated Clothing Workers Amalgamated Clothing Workers of America (ACWA) was a United States labor union known for its support for "social unionism" and progressive political causes. Led by Sidney Hillman for its first thirty years, it helped found the Congress of Ind ...

Los Angeles, California Los Angeles ( ; es, Los Ángeles, link=no , ), often referred to by its initials L.A., is the largest city in the state of California and the second most populous city in the United States after New York City, as well as one of the wo ...

. His father came from Cromane, a small fishing village in

County Kerry County Kerry ( gle, Contae Chiarraí) is a county in Ireland. It is located in the South-West Region and forms part of the province of Munster. It is named after the Ciarraige who lived in part of the present county. The population of the cou ...

, Ireland. His mother died in 1957. Both parents were active members of the

Communist Party A communist party is a political party that seeks to realize the socio-economic goals of communism. The term ''communist party'' was popularized by the title of '' The Manifesto of the Communist Party'' (1848) by Karl Marx and Friedrich Engels. ...

during the 1930s, and they encouraged learning and critical thinking. Before he attended high school, he got interested in science by reading a translation of a Russian popular science book for children, called ''100,000 Whys''. John was fluent in the Russian language and made friends with Russian scientists during multiple trips to the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

but he became disillusioned after making visits to the

Soviet Bloc The Eastern Bloc, also known as the Communist Bloc and the Soviet Bloc, was the group of socialist states of Central and Eastern Europe, East Asia, Southeast Asia, Africa, and Latin America under the influence of the Soviet Union that existed du ...

which led to him becoming a

conservative Conservatism is a cultural, social, and political philosophy that seeks to promote and to preserve traditional institutions, practices, and values. The central tenets of conservatism may vary in relation to the culture and civilization in ...

Republican. McCarthy graduated from Belmont High School two years early. McCarthy was accepted into Caltech in 1944. McCarthy showed an early aptitude for mathematics; during his teens he taught himself college mathematics by studying the textbooks used at the nearby

California Institute of Technology The California Institute of Technology (branded as Caltech or CIT)The university itself only spells its short form as "Caltech"; the institution considers other spellings such a"Cal Tech" and "CalTech" incorrect. The institute is also occasional ...

(Caltech). As a result, he was able to skip the first two years of mathematics at Caltech. McCarthy was suspended from Caltech for failure to attend

physical education Physical education, often abbreviated to Phys Ed. or P.E., is a subject taught in schools around the world. It is usually taught during primary and secondary education, and encourages psychomotor learning by using a play and movement explora ...

courses. He then served in the

US Army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, c ...

and was readmitted, receiving a BS in mathematics in 1948. It was at Caltech that he attended a lecture by

John von Neumann John von Neumann (; hu, Neumann János Lajos, ; December 28, 1903 – February 8, 1957) was a Hungarian-American mathematician, physicist, computer scientist, engineer and polymath. He was regarded as having perhaps the widest cove ...

that inspired his future endeavors. McCarthy initially completed graduate studies at Caltech before moving to

Princeton University Princeton University is a private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth as the College of New Jersey, Princeton is the fourth-oldest institution of higher education in the United States and one of the n ...

. He received a

PhD PHD or PhD may refer to: * Doctor of Philosophy (PhD), an academic qualification Entertainment * '' PhD: Phantasy Degree'', a Korean comic series * ''Piled Higher and Deeper'', a web comic * Ph.D. (band), a 1980s British group ** Ph.D. (Ph.D. albu ...

in mathematics from Princeton in 1951 after completing a doctoral dissertation, titled " Projection operators and

partial differential equation In mathematics, a partial differential equation (PDE) is an equation which imposes relations between the various partial derivatives of a multivariable function. The function is often thought of as an "unknown" to be solved for, similarly to ...

s", under the supervision of Donald C. Spencer.

Academic career

After short-term appointments at Princeton and Stanford University, McCarthy became an assistant professor at

Dartmouth Dartmouth may refer to: Places * Dartmouth, Devon, England ** Dartmouth Harbour * Dartmouth, Massachusetts, United States * Dartmouth, Nova Scotia, Canada * Dartmouth, Victoria, Australia Institutions * Dartmouth College, Ivy League university i ...

in 1955. A year later, McCarthy moved to MIT as a research

fellow A fellow is a concept whose exact meaning depends on context. In learned or professional societies, it refers to a privileged member who is specially elected in recognition of their work and achievements. Within the context of higher education ...

in the autumn of 1956. By the end of his years at MIT he was already affectionately referred to as "Uncle John" by his students. In 1962, McCarthy became a full

professor Professor (commonly abbreviated as Prof.) is an academic rank at universities and other post-secondary education and research institutions in most countries. Literally, ''professor'' derives from Latin as a "person who professes". Professor ...

at Stanford, where he remained until his retirement in 2000. McCarthy championed mathematics such as

lambda calculus Lambda calculus (also written as ''λ''-calculus) is a formal system in mathematical logic for expressing computation based on function abstraction and application using variable binding and substitution. It is a universal model of computation t ...

and invented logics for achieving

common sense ''Common Sense'' is a 47-page pamphlet written by Thomas Paine in 1775–1776 advocating independence from Great Britain to people in the Thirteen Colonies. Writing in clear and persuasive prose, Paine collected various moral and political arg ...

in artificial intelligence.

Contributions in computer science

John McCarthy is one of the "founding fathers" of artificial intelligence, together with

Alan Turing Alan Mathison Turing (; 23 June 1912 – 7 June 1954) was an English mathematician, computer scientist, logician, cryptanalyst, philosopher, and theoretical biologist. Turing was highly influential in the development of theoretical c ...

Marvin Minsky Marvin Lee Minsky (August 9, 1927 – January 24, 2016) was an American cognitive and computer scientist concerned largely with research of artificial intelligence (AI), co-founder of the Massachusetts Institute of Technology's AI laboratory, a ...

, Allen Newell, and Herbert A. Simon. McCarthy, Minsky, Nathaniel Rochester and

Claude E. Shannon Claude Elwood Shannon (April 30, 1916 – February 24, 2001) was an American mathematician, electrical engineer, and cryptographer known as a "father of information theory". As a 21-year-old master's degree student at the Massachusetts Institu ...

coined the term "artificial intelligence" in a proposal that they wrote for the famous Dartmouth conference in Summer 1956. This conference started AI as a field. (Minsky later joined McCarthy at MIT in 1959.) In 1958, he proposed the advice taker, which inspired later work on question-answering and

logic programming Logic programming is a programming paradigm which is largely based on formal logic Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the science of deductively valid inferences or of log ...

. In the late 1950s, McCarthy discovered that

primitive recursive function In computability theory, a primitive recursive function is roughly speaking a function that can be computed by a computer program whose loops are all "for" loops (that is, an upper bound of the number of iterations of every loop can be determined ...

s could be extended to compute with symbolic expressions, producing the

Lisp programming language Lisp (historically LISP) is a family of programming languages with a long history and a distinctive, fully parenthesized prefix notation. Originally specified in 1960, Lisp is the second-oldest high-level programming language still in common ...

. That functional programming seminal paper, also introduced the lambda notation borrowed from the syntax of

in which later dialects like Scheme based its semantics. Lisp soon became the programming language of choice for AI applications after its publication in 1960. In 1958, McCarthy served on an ACM Ad hoc Committee on Languages that became part of the committee that designed

ALGOL 60 ALGOL 60 (short for ''Algorithmic Language 1960'') is a member of the ALGOL family of computer programming languages. It followed on from ALGOL 58 which had introduced code blocks and the begin and end pairs for delimiting them, representing a k ...

. In August 1959 he proposed the use of recursion and conditional expressions, which became part of ALGOL. He then became involved with developing international standards in programming and informatics, as a member of the

International Federation for Information Processing The International Federation for Information Processing (IFIP) is a global organisation for researchers and professionals working in the field of computing to conduct research, develop standards and promote information sharing. Established in 196 ...

(IFIP) IFIP Working Group 2.1 on Algorithmic Languages and Calculi, which specified, maintains, and supports ALGOL 60 and

ALGOL 68 ALGOL 68 (short for ''Algorithmic Language 1968'') is an imperative programming language that was conceived as a successor to the ALGOL 60 programming language, designed with the goal of a much wider scope of application and more rigorously ...

. Around 1959, he invented so-called " garbage collection" methods, a kind of automatic memory management, to solve problems in Lisp. He helped to motivate the creation of

Project MAC Computer Science and Artificial Intelligence Laboratory (CSAIL) is a research institute at the Massachusetts Institute of Technology (MIT) formed by the 2003 merger of the Laboratory for Computer Science (LCS) and the Artificial Intelligence La ...

at MIT when he worked there, and at Stanford University, he helped establish the

Stanford AI Laboratory Stanford University has many centers and institutes dedicated to the study of various specific topics. These centers and institutes may be within a department, within a school but across departments, an independent laboratory, institute or center ...

, for many years a friendly rival to Project MAC. McCarthy was instrumental in the creation of three of the very earliest time-sharing systems (

Compatible Time-Sharing System The Compatible Time-Sharing System (CTSS) was the first general purpose time-sharing operating system. Compatible Time Sharing referred to time sharing which was compatible with batch processing; it could offer both time sharing and batch proce ...

, BBN Time-Sharing System, and Dartmouth Time Sharing System). His colleague Lester Earnest told the Los Angeles Times: In 1961, he was perhaps the first to suggest publicly the idea of

utility computing Utility computing or The Computer Utility is a service provisioning model in which a service provider makes computing resources and infrastructure management available to the customer as needed, and charges them for specific usage rather than a ...

, in a speech given to celebrate MIT's centennial: that computer

technology might result in a future in which computing power and even specific applications could be sold through the

utility As a topic of economics, utility is used to model worth or value. Its usage has evolved significantly over time. The term was introduced initially as a measure of pleasure or happiness as part of the theory of utilitarianism by moral philosoph ...

business model (like

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as ...

electricity Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as describ ...

). This idea of a computer or information utility was very popular during the late 1960s, but had faded by the mid-1990s. However, since 2000, the idea has resurfaced in new forms (see

application service provider An application service provider (ASP) is a business providing application software generally through the Web. The ASP model The application software resides on the vendor's system and is accessed by users through a communication protocol. Altern ...

grid computing Grid computing is the use of widely distributed computer resources to reach a common goal. A computing grid can be thought of as a distributed system with non-interactive workloads that involve many files. Grid computing is distinguished from ...

, and

cloud computing Cloud computing is the on-demand availability of computer system resources, especially data storage ( cloud storage) and computing power, without direct active management by the user. Large clouds often have functions distributed over m ...

). In 1966, McCarthy and his team at Stanford wrote a computer program used to play a series of

chess Chess is a board game for two players, called White and Black, each controlling an army of chess pieces in their color, with the objective to checkmate the opponent's king. It is sometimes called international chess or Western chess to dist ...

games with counterparts in the

; McCarthy's team lost two games and drew two games (see Kotok-McCarthy). From 1978 to 1986, McCarthy developed the circumscription method of non-monotonic reasoning. In 1982, he seems to have originated the idea of the '' space fountain'', a type of tower extending into space and kept vertical by the outward force of a stream of pellets propelled from Earth along a sort of conveyor belt which returns the pellets to Earth. Payloads would ride the conveyor belt upward.

Other activities

McCarthy often commented on world affairs on the

Usenet Usenet () is a worldwide distributed discussion system available on computers. It was developed from the general-purpose Unix-to-Unix Copy (UUCP) dial-up network architecture. Tom Truscott and Jim Ellis conceived the idea in 1979, and it was ...

forums. Some of his ideas can be found in his sustainability Web page, which is "aimed at showing that human material progress is desirable and sustainable". McCarthy was a serious book reader, an optimist, and a staunch supporter of free speech. His best Usenet interaction is visible in rec.arts.books archives. And McCarthy actively attended SF Bay Area dinners in

Palo Alto Palo Alto (; Spanish for "tall stick") is a charter city in the northwestern corner of Santa Clara County, California, United States, in the San Francisco Bay Area, named after a coastal redwood tree known as El Palo Alto. The city was es ...

of r.a.b. readers called rab-fests. He went on to defend free speech criticism involving European ethnic jokes at Stanford. McCarthy saw the importance of mathematics and mathematics education. His

.sig A signature block (often abbreviated as signature, sig block, sig file, .sig, dot sig, siggy, or just sig) is a personalized block of text automatically appended at the bottom of an email message, Usenet article, or forum post. Email and Usenet ...

for years was, "He who refuses to do arithmetic is doomed to talk nonsense"; his license plate cover read, similarly, "Do the arithmetic or be doomed to talk nonsense." He advised 30 PhD graduates. His 2001 short story "The Robot and the Baby" farcically explored the question of whether robots should have (or simulate having) emotions, and anticipated aspects of Internet culture and social networking that have become increasingly prominent during ensuing decades.

Personal life

McCarthy was married three times. His second wife was Vera Watson, a programmer and

mountaineer Mountaineering or alpinism, is a set of outdoor activities that involves ascending tall mountains. Mountaineering-related activities include traditional outdoor climbing, skiing, and traversing via ferratas. Indoor climbing, sport climbing, an ...

who died in 1978 attempting to scale Annapurna I Central as part of an all-women expedition. He later married Carolyn Talcott, a computer scientist at Stanford and later

SRI International SRI International (SRI) is an American nonprofit organization, nonprofit scientific research, scientific research institute and organization headquartered in Menlo Park, California. The trustees of Stanford University established SRI in 1946 as ...

. McCarthy declared himself an atheist in a speech about Artificial Intelligence at Stanford Memorial Church. Raised as a

Communist Communism (from Latin la, communis, lit=common, universal, label=none) is a far-left sociopolitical, philosophical, and economic ideology and current within the socialist movement whose goal is the establishment of a communist society, a ...

, he became a conservative Republican after a visit to

Czechoslovakia , rue, Чеськословеньско, , yi, טשעכאסלאוואקיי, , common_name = Czechoslovakia , life_span = 1918–19391945–1992 , p1 = Austria-Hungary , image_p1 ...

in 1968 after the Soviet invasion. McCarthy died at his home in Stanford on October 24, 2011.

Philosophy of artificial intelligence

In 1979 McCarthy wrote an article entitled "Ascribing Mental Qualities to Machines". In it he wrote, "Machines as simple as thermostats can be said to have beliefs, and having beliefs seems to be a characteristic of most machines capable of problem-solving performance." In 1980 the philosopher

John Searle John Rogers Searle (; born July 31, 1932) is an American philosopher widely noted for contributions to the philosophy of language, philosophy of mind, and social philosophy. He began teaching at UC Berkeley in 1959, and was Willis S. and Mari ...

responded with his famous

Chinese Room The Chinese room argument holds that a digital computer executing a program cannot have a " mind," "understanding" or "consciousness," regardless of how intelligently or human-like the program may make the computer behave. The argument was pre ...

Argument, disagreeing with McCarthy and taking the stance that machines cannot have beliefs simply because they are not conscious. Searle argues that machines lack "understanding" or "

intentionality ''Intentionality'' is the power of minds to be about something: to represent or to stand for things, properties and states of affairs. Intentionality is primarily ascribed to mental states, like perceptions, beliefs or desires, which is why it ha ...

" (a term commonly used in the philosophy of mind). A vast amount of literature has been written in support of one side or the other.

Awards and honors

from the

Association for Computing Machinery The Association for Computing Machinery (ACM) is a US-based international learned society for computing. It was founded in 1947 and is the world's largest scientific and educational computing society. The ACM is a non-profit professional member ...

(1971). * Kyoto Prize (1988). *

(USA) in Mathematical, Statistical, and Computational Sciences (1990). * Inducted as a Fellow of the

Computer History Museum The Computer History Museum (CHM) is a museum of computer history, located in Mountain View, California. The museum presents stories and artifacts of Silicon Valley and the information age, and explores the computing revolution and its impact ...

"for his co-founding of the fields of Artificial Intelligence (AI) and timesharing systems, and for major contributions to mathematics and computer science". (1999) * Benjamin Franklin Medal in Computer and Cognitive Science from the

Franklin Institute The Franklin Institute is a science museum and the center of science education and research in Philadelphia, Pennsylvania. It is named after the American scientist and statesman Benjamin Franklin. It houses the Benjamin Franklin National Memor ...

(2003). * Inducted into

IEEE Intelligent Systems ''IEEE Intelligent Systems'' is a bimonthly peer-reviewed academic journal published by the IEEE Computer Society and sponsored by the Association for the Advancement of Artificial Intelligence (AAAI), British Computer Society (BCS), and European ...

' AI's Hall of Fame (2011), for the "significant contributions to the field of AI and intelligent systems". * Named as one of the 2012

Stanford Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is consider ...

Engineering Heroes.

Major publications

* McCarthy, J. 1959. . In ''Proceedings of the Teddington Conference on the Mechanization of Thought Processes'', 756–91. London: Her Majesty's Stationery Office. * McCarthy, J. 1960. . ''Communications of the ACM'' 3(4):184-195. * McCarthy, J. 1963a "A basis for a mathematical theory of computation". In ''Computer Programming and formal systems''. North-Holland. * McCarthy, J. 1963b. Situations, actions, and causal laws. Technical report, Stanford University. * McCarthy, J., and Hayes, P. J. 1969. . In Meltzer, B., and Michie, D., eds., ''Machine Intelligence'' 4. Edinburgh: Edinburgh University Press. 463–502. * McCarthy, J. 1977. "Epistemological problems of artificial intelligence". In ''IJCAI'', 1038–1044. * * * McCarthy, J. 1990. "Generality in artificial intelligence". In Lifschitz, V., ed., ''Formalizing Common Sense''. Ablex. 226–236. * McCarthy, J. 1993. "Notes on formalizing context". In ''IJCAI'', 555–562. * McCarthy, J., and Buvac, S. 1997. "Formalizing context: Expanded notes". In Aliseda, A.; van Glabbeek, R.; and Westerstahl, D., eds., ''Computing Natural Language''. Stanford University. Also available as Stanford Technical Note STAN-CS-TN-94-13. * McCarthy, J. 1998. "Elaboration tolerance". In ''Working Papers of the Fourth International Symposium on Logical formalizations of Commonsense Reasoning'', Commonsense-1998. * Costello, T., and McCarthy, J. 1999. "Useful counterfactuals". '' Electronic Transactions on Artificial Intelligence'' 3(A):51-76 * McCarthy, J. 2002. "Actions and other events in situation calculus". In Fensel, D.; Giunchiglia, F.; McGuinness, D.; and Williams, M., eds., ''Proceedings of KR-2002'', 615–628.

References

External links

* . * * *
Celebration of John McCarthy's Accomplishments at Stanford University

Interview with Guy Steele
conducted at OOPSLA 2008; Set of interviews:
Oral history interview with John McCarthy
at

Charles Babbage Institute The IT History Society (ITHS) is an organization that supports the history and scholarship of information technology by encouraging, fostering, and facilitating archival and historical research. Formerly known as the Charles Babbage Foundation, ...

, University of Minnesota, Minneapolis. McCarthy discusses his role in the development of time-sharing at the Massachusetts Institute of Technology. He also describes his work in artificial intelligence (AI) funded by the Advanced Research Projects Agency, including logic-based AI (Lisp) and robotics.
Oral history interview with Marvin Minsky
at Charles Babbage Institute, University of Minnesota, Minneapolis. Minsky describes artificial intelligence (AI) research at the Massachusetts Institute of Technology (MIT), including the work of John McCarthy.
Oral history interview with Jack B. Dennis
at Charles Babbage Institute, University of Minnesota, Minneapolis. Dennis discusses the work of John McCarthy on time-sharing, and the influence of DARPA's Information Processing Techniques Office on the development of time-sharing.
Oral history interview with Fernando J. Corbató
at Charles Babbage Institute, University of Minnesota, Minneapolis. Corbató discusses computer science research, especially time-sharing, at the Massachusetts Institute of Technology (MIT), including John McCarthy and research on time-sharing.
National Academy of Sciences Biographical Memoir
{{DEFAULTSORT:Mccarthy, John 1927 births 2011 deaths Belmont High School (Los Angeles) alumni American computer scientists Artificial intelligence researchers California Institute of Technology alumni Fellows of the Association for the Advancement of Artificial Intelligence Fellows of the Association for Computing Machinery Formal methods people History of artificial intelligence American people of Irish descent American people of Lithuanian-Jewish descent Kyoto laureates in Advanced Technology Lisp (programming language) people Members of the United States National Academy of Sciences National Medal of Science laureates People from Boston Programming language designers Logic programming researchers Stanford University School of Engineering faculty Turing Award laureates Usenet people Princeton University alumni Dartmouth College faculty Princeton University faculty Massachusetts Institute of Technology faculty People from Stanford, California Jewish American atheists Scientists from California United States Army soldiers Computer chess people Fellows of the Cognitive Science Society Presidents of the Association for the Advancement of Artificial Intelligence California Republicans