Hilary Whitehall Putnam (; July 31, 1926 – March 13, 2016) was an American philosopher, mathematician, and computer scientist, and a major figure in
analytic philosophy
Analytic philosophy is a branch and tradition of philosophy using analysis, popular in the Western world and particularly the Anglosphere, which began around the turn of the 20th century in the contemporary era in the United Kingdom, United Sta ...
in the second half of the 20th century. He made significant contributions to
philosophy of mind
Philosophy of mind is a branch of philosophy that studies the ontology and nature of the mind and its relationship with the body. The mind–body problem is a paradigmatic issue in philosophy of mind, although a number of other issues are addre ...
,
philosophy of language
In analytic philosophy, philosophy of language investigates the nature of language and the relations between language, language users, and the world. Investigations may include inquiry into the nature of meaning, intentionality, reference, ...
,
philosophy of mathematics
The philosophy of mathematics is the branch of philosophy that studies the assumptions, foundations, and implications of mathematics. It aims to understand the nature and methods of mathematics, and find out the place of mathematics in people's ...
, and
philosophy of science
Philosophy of science is a branch of philosophy concerned with the foundations, methods, and implications of science. The central questions of this study concern what qualifies as science, the reliability of scientific theories, and the ultim ...
.
Outside philosophy, Putnam contributed to
mathematics
Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...
and
computer science
Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical discipli ...
. Together with
Martin Davis he developed the
Davis–Putnam algorithm The Davis–Putnam algorithm was developed by Martin Davis and Hilary Putnam for checking the validity of a first-order logic formula using a resolution-based decision procedure for propositional logic. Since the set of valid first-order formulas ...
for the
Boolean satisfiability problem
In logic and computer science, the Boolean satisfiability problem (sometimes called propositional satisfiability problem and abbreviated SATISFIABILITY, SAT or B-SAT) is the problem of determining if there exists an interpretation that satisfie ...
and he helped demonstrate the unsolvability of
Hilbert's tenth problem
Hilbert's tenth problem is the tenth on the list of mathematical problems that the German mathematician David Hilbert posed in 1900. It is the challenge to provide a general algorithm which, for any given Diophantine equation (a polynomial equat ...
.
Putnam was known for his willingness to apply equal scrutiny to his own philosophical positions as to those of others, subjecting each position to rigorous analysis until he exposed its flaws.
As a result, he acquired a reputation for frequently changing his positions. In philosophy of mind, Putnam is known for his argument against the
type-identity of mental and physical states based on his hypothesis of the
multiple realizability
Multiple realizability, in the philosophy of mind, is the thesis that the same mental property, state, or event can be implemented by different physical properties, states, or events. Philosophers of mind have used multiple realizability to argue ...
of
the mental, and for the concept of
functionalism, an influential theory regarding the
mind–body problem
The mind–body problem is a philosophical debate concerning the relationship between thought and consciousness in the human mind, and the brain as part of the physical body. The debate goes beyond addressing the mere question of how mind and bo ...
.
In philosophy of language, along with
Saul Kripke
Saul Aaron Kripke (; November 13, 1940 – September 15, 2022) was an American philosopher and logician in the analytic tradition. He was a Distinguished Professor of Philosophy at the Graduate Center of the City University of New York and emerit ...
and others, he developed the
causal theory of reference A causal theory of reference or historical chain theory of reference is a theory of how terms acquire specific referents based on evidence. Such theories have been used to describe many referring terms, particularly logical terms, proper names, and ...
, and formulated an original theory of meaning, introducing the notion of
semantic externalism
In the philosophy of language, semantic externalism (the opposite of semantic internalism) is the view that the meaning of a term is determined, in whole or in part, by factors external to the speaker. According to an externalist position, one can ...
based on a
thought experiment
A thought experiment is a hypothetical situation in which a hypothesis, theory, or principle is laid out for the purpose of thinking through its consequences.
History
The ancient Greek ''deiknymi'' (), or thought experiment, "was the most anci ...
called
Twin Earth.
In
philosophy of mathematics
The philosophy of mathematics is the branch of philosophy that studies the assumptions, foundations, and implications of mathematics. It aims to understand the nature and methods of mathematics, and find out the place of mathematics in people's ...
, Putnam and
W. V. O. Quine W. may refer to:
* SoHo (Australian TV channel) (previously W.), an Australian pay television channel
* ''W.'' (film), a 2008 American biographical drama film based on the life of George W. Bush
* "W.", the fifth track from Codeine's 1992 EP ''Bar ...
developed the
Quine–Putnam indispensability argument
The Quine–Putnam indispensability argument is an argument in the philosophy of mathematics for the existence of abstract mathematical objects such as numbers and sets, a position known as mathematical platonism. It was named after the phil ...
, an argument for the reality of mathematical entities,
later espousing the view that mathematics is not purely logical, but "
quasi-empirical".
[ 2nd ed., Cambridge: Cambridge University Press, 1983.] In
epistemology
Epistemology (; ), or the theory of knowledge, is the branch of philosophy concerned with knowledge. Epistemology is considered a major subfield of philosophy, along with other major subfields such as ethics, logic, and metaphysics.
Episte ...
, Putnam is known for his critique of the well-known "
brain in a vat
In philosophy, the brain in a vat (BIV) is a scenario used in a variety of thought experiments intended to draw out certain features of human conceptions of knowledge, reality, truth, mind, consciousness, and meaning. It is a modern incarna ...
" thought experiment. This thought experiment appears to provide a powerful argument for
epistemological skepticism
Philosophical skepticism (American and British English spelling differences, UK spelling: scepticism; from Ancient Greek, Greek σκέψις ''skepsis'', "inquiry") is a family of Philosophy, philosophical views that question the possibility o ...
, but Putnam challenges its coherence.
[ reprinted in ] In
metaphysics
Metaphysics is the branch of philosophy that studies the fundamental nature of reality, the first principles of being, identity and change, space and time, causality, necessity, and possibility. It includes questions about the nature of conscio ...
, he originally espoused a position called
metaphysical realism, but eventually became one of its most outspoken critics, first adopting a view he called "
internal realism",
which he later abandoned. Despite these changes of view, throughout his career Putnam remained committed to
scientific realism
Scientific realism is the view that the universe described by science is real regardless of how it may be interpreted.
Within philosophy of science, this view is often an answer to the question "how is the success of science to be explained?" Th ...
, roughly the view that mature scientific theories are approximately true descriptions of ways things are.
In his later work, Putnam became increasingly interested in
American pragmatism
Pragmatism is a philosophical tradition that considers words and thought as tools and instruments for prediction, problem solving, and action, and rejects the idea that the function of thought is to describe, represent, or mirror reality. Pr ...
,
Jewish philosophy
Jewish philosophy () includes all philosophy carried out by Jews, or in relation to the religion of Judaism. Until modern ''Haskalah'' (Jewish Enlightenment) and Jewish emancipation, Jewish philosophy was preoccupied with attempts to reconcile ...
, and
ethics
Ethics or moral philosophy is a branch of philosophy that "involves systematizing, defending, and recommending concepts of right and wrong behavior".''Internet Encyclopedia of Philosophy'' The field of ethics, along with aesthetics, concerns m ...
, engaging with a wider array of philosophical traditions. He also displayed an interest in
metaphilosophy
Metaphilosophy, sometimes called the philosophy of philosophy, is "the investigation of the nature of philosophy". Its subject matter includes the aims of philosophy, the boundaries of philosophy, and its methods. Thus, while philosophy character ...
, seeking to "renew philosophy" from what he identified as narrow and inflated concerns.
He was at times a politically controversial figure, especially for his involvement with the
Progressive Labor Party in the late 1960s and early 1970s.
Life
Hilary Whitehall Putnam was born on July 31, 1926, in
Chicago
(''City in a Garden''); I Will
, image_map =
, map_caption = Interactive Map of Chicago
, coordinates =
, coordinates_footnotes =
, subdivision_type = Country
, subdivision_name ...
,
Illinois
Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...
.
His father,
Samuel Putnam
Samuel Putnam (October 10, 1892 – January 15, 1950) was an American translator and scholar of Romance languages. He is also noteworthy as the author of ''Paris Was Our Mistress'', a memoir on writers and artists associated with the American ex-p ...
, was a scholar of Romance languages, columnist, and translator who wrote for the ''
Daily Worker
The ''Daily Worker'' was a newspaper published in New York City by the Communist Party USA, a formerly Comintern-affiliated organization. Publication began in 1924. While it generally reflected the prevailing views of the party, attempts were m ...
'', a publication of the
American Communist Party
The Communist Party USA, officially the Communist Party of the United States of America (CPUSA), is a communist party in the United States which was established in 1919 after a split in the Socialist Party of America following the Russian Revo ...
, from 1936 to 1946. Because of his father's commitment to communism, Putnam had a secular upbringing, although his mother, Riva, was
Jewish
Jews ( he, יְהוּדִים, , ) or Jewish people are an ethnoreligious group and nation originating from the Israelites Israelite origins and kingdom: "The first act in the long drama of Jewish history is the age of the Israelites""The ...
.
[ In early 1927, six months after Hilary's birth, the family moved to France, where Samuel was under contract to translate the surviving works of ]François Rabelais
François Rabelais ( , , ; born between 1483 and 1494; died 1553) was a French Renaissance writer, physician, Renaissance humanist, monk and Greek scholar. He is primarily known as a writer of satire, of the grotesque, and of bawdy jokes and ...
. In a 2015 autobiographical essay, Putnam said that his first childhood memories were from his life in France, and his first language was French.
Putnam completed the first two years of his primary education
Primary education or elementary education is typically the first stage of formal education, coming after preschool/kindergarten and before secondary school. Primary education takes place in ''primary schools'', ''elementary schools'', or first ...
in France before he and his parents returned to the U.S. in 1933, settling in Philadelphia
Philadelphia, often called Philly, is the largest city in the Commonwealth of Pennsylvania, the sixth-largest city in the U.S., the second-largest city in both the Northeast megalopolis and Mid-Atlantic regions after New York City. Sinc ...
. There, he attended Central High School, where he met Noam Chomsky
Avram Noam Chomsky (born December 7, 1928) is an American public intellectual: a linguist, philosopher, cognitive scientist, historian, social critic, and political activist. Sometimes called "the father of modern linguistics", Chomsky is ...
, who was a year behind him. The two remained friends—and often intellectual opponents—for the rest of Putnam's life. Putnam studied philosophy at the University of Pennsylvania
The University of Pennsylvania (also known as Penn or UPenn) is a private research university in Philadelphia. It is the fourth-oldest institution of higher education in the United States and is ranked among the highest-regarded universitie ...
, receiving his B.A.
Bachelor of arts (BA or AB; from the Latin ', ', or ') is a bachelor's degree awarded for an undergraduate program in the arts, or, in some cases, other disciplines. A Bachelor of Arts degree course is generally completed in three or four yea ...
degree and becoming a member of the Philomathean Society
The Philomathean Society of the University of Pennsylvania is a collegiate literary society, the oldest student group at the university, and a claimant to the title of the oldest continuously-existing literary society in the United States.This cl ...
, the country's oldest continually existing collegiate literary society. He did graduate work in philosophy at Harvard University
Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher le ...
and later at UCLA
The University of California, Los Angeles (UCLA) is a public land-grant research university in Los Angeles, California. UCLA's academic roots were established in 1881 as a teachers college then known as the southern branch of the California St ...
's philosophy department, where he received his Ph.D.
A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is ...
in 1951 for his dissertation, ''The Meaning of the Concept of Probability in Application to Finite Sequences''. Putnam's dissertation supervisor Hans Reichenbach was a leading figure in logical positivism
Logical positivism, later called logical empiricism, and both of which together are also known as neopositivism, is a movement in Western philosophy whose central thesis was the verification principle (also known as the verifiability criterion o ...
, the dominant school of philosophy of the day; one of Putnam's most consistent positions was his rejection of logical positivism as self-defeating. Over the course of his life, Putnam was his own philosophical adversary, changing his positions on philosophical questions and critiquing his previous views.
After obtaining his PhD, Putnam taught at Northwestern University
Northwestern University is a private research university in Evanston, Illinois. Founded in 1851, Northwestern is the oldest chartered university in Illinois and is ranked among the most prestigious academic institutions in the world.
Charte ...
(1951–52), Princeton University
Princeton University is a private university, private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial Colleges, fourth-oldest ins ...
(1953–61), and MIT
The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the m ...
(1961–65). In 1962, he married fellow philosopher Ruth Anna Putnam (born Ruth Anna Jacobs), who took a teaching position in philosophy at Wellesley College
Wellesley College is a private women's liberal arts college in Wellesley, Massachusetts, United States. Founded in 1870 by Henry and Pauline Durant as a female seminary, it is a member of the original Seven Sisters Colleges, an unofficial g ...
. Rebelling against the antisemitism
Antisemitism (also spelled anti-semitism or anti-Semitism) is hostility to, prejudice towards, or discrimination against Jews. A person who holds such positions is called an antisemite. Antisemitism is considered to be a form of racism.
Antis ...
they experienced during their youth, the Putnams decided to establish a traditional Jewish home for their children. Since they had no experience with the rituals of Judaism, they sought out invitations to other Jewish homes for Seder
The Passover Seder (; he, סדר פסח , 'Passover order/arrangement'; yi, סדר ) is a ritual feast at the beginning of the Jewish holiday of Passover. It is conducted throughout the world on the eve of the 15th day of Nisan in the Hebrew c ...
. They began to study Jewish rituals and Hebrew
Hebrew (; ; ) is a Northwest Semitic language of the Afroasiatic language family. Historically, it is one of the spoken languages of the Israelites and their longest-surviving descendants, the Jews and Samaritans. It was largely preserved ...
, became more interested in Judaism, self-identified as Jews, and actively practiced Judaism. In 1994, Hilary celebrated a belated bar mitzvah service; Ruth Anna's bat mitzvah was celebrated four years later.
In the 1960s and early 1970s, Putnam was an active supporter of the American Civil Rights Movement
The civil rights movement was a nonviolent social and political movement and campaign from 1954 to 1968 in the United States to abolish legalized institutional racial segregation, discrimination, and disenfranchisement throughout the United ...
and he was also an active opponent of the Vietnam War. In 1963, he organized one of MIT's first faculty and student anti-war committees. After moving to Harvard in 1965, he organized campus protests and began teaching courses on Marxism
Marxism is a Left-wing politics, left-wing to Far-left politics, far-left method of socioeconomic analysis that uses a Materialism, materialist interpretation of historical development, better known as historical materialism, to understand S ...
. Putnam became an official faculty advisor to the Students for a Democratic Society
Students for a Democratic Society (SDS) was a national student activist organization in the United States during the 1960s, and was one of the principal representations of the New Left. Disdaining permanent leaders, hierarchical relationships ...
and in 1968 a member of the Progressive Labor Party (PLP). He was elected a Fellow of the American Academy of Arts and Sciences
The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and ...
in 1965. After 1968, his political activities centered on the PLP. The Harvard administration considered these activities disruptive and attempted to censure Putnam. Putnam permanently severed his relationship with the PLP in 1972. In 1997, at a meeting of former draft resistance activists at Boston's Arlington Street Church, he called his involvement with the PLP a mistake. He said he had been impressed at first with the PLP's commitment to alliance-building and its willingness to attempt to organize from within the armed forces.
In 1976, Putnam was elected president of the American Philosophical Association
The American Philosophical Association (APA) is the main professional organization for philosophers in the United States. Founded in 1900, its mission is to promote the exchange of ideas among philosophers, to encourage creative and scholarly ...
. The next year, he was selected as Walter Beverly Pearson Professor of Mathematical Logic in recognition of his contributions to the philosophy of logic
Philosophy of logic is the area of philosophy that studies the scope and nature of logic. It investigates the philosophical problems raised by logic, such as the presuppositions often implicitly at work in theories of logic and in their application ...
and mathematics. While breaking with his radical past, Putnam never abandoned his belief that academics have a particular social and ethical responsibility toward society. He continued to be forthright and progressive in his political views, as expressed in the articles "How Not to Solve Ethical Problems" (1983) and "Education for Democracy" (1993).
Putnam was a Corresponding Fellow of the British Academy
The British Academy is the United Kingdom's national academy for the humanities and the social sciences.
It was established in 1902 and received its royal charter in the same year. It is now a fellowship of more than 1,000 leading scholars span ...
. He was elected to the American Philosophical Society
The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and communit ...
in 1999. He retired from teaching in June 2000, becoming Cogan University Professor Emeritus, but as of 2009 continued to give a seminar almost yearly at Tel Aviv University
Tel Aviv University (TAU) ( he, אוּנִיבֶרְסִיטַת תֵּל אָבִיב, ''Universitat Tel Aviv'') is a public research university in Tel Aviv, Israel. With over 30,000 students, it is the largest university in the country. Locate ...
. He also held the Spinoza Chair of Philosophy at the University of Amsterdam
The University of Amsterdam (abbreviated as UvA, nl, Universiteit van Amsterdam) is a public research university located in Amsterdam, Netherlands. The UvA is one of two large, publicly funded research universities in the city, the other being ...
in 2001. His corpus includes five volumes of collected works, seven books, and more than 200 articles. Putnam's renewed interest in Judaism inspired him to publish several books and essays on the topic. With his wife, he co-authored several essays and a book on the late-19th-century American pragmatist movement.
For his contributions in philosophy and logic, Putnam was awarded the Rolf Schock Prize
The Rolf Schock Prizes were established and endowed by bequest of philosopher and artist Rolf Schock (1933–1986). The prizes were first awarded in Stockholm, Sweden, in 1993 and, since 2005, are awarded every three years. Each recipient current ...
in 2011 and the Nicholas Rescher Prize for Systematic Philosophy
The Nicholas Rescher Prize for Systematic Philosophy was established by the University of Pittsburgh in 2009 to counter present-day tendencies to narrow specialization by rewarding and showcasing the work of philosophers who have addressed the his ...
in 2015. Putnam died at his home in Arlington, , on March 13, 2016. At the time of his death, Putnam was Cogan University Professor Emeritus at Harvard University.
Philosophy of mind
Multiple realizability
Putnam's best-known work concerns philosophy of mind. His most noted original contributions to that field came in several key papers published in the late 1960s that set out the hypothesis of multiple realizability
Multiple realizability, in the philosophy of mind, is the thesis that the same mental property, state, or event can be implemented by different physical properties, states, or events. Philosophers of mind have used multiple realizability to argue ...
. In these papers, Putnam argues that, contrary to the famous claim of the type-identity theory, pain may correspond to utterly different physical states of the nervous system in different organisms even if they all experience the same mental state of "being in pain". Putnam cited examples from the animal kingdom to illustrate his thesis. He asked whether it was likely that the brain structures of diverse types of animals realize pain, or other mental states, the same way. If they do not share the same brain structures, they cannot share the same mental states
A mental state, or a mental property, is a state of mind of a person. Mental states comprise a diverse class, including perception, pain experience, belief, desire, intention, emotion, and memory. There is controversy concerning the exact definiti ...
and properties, in which case mental states must be realized by different physical states in different species. Putnam then took his argument a step further, asking about such things as the nervous systems of alien beings, artificially intelligent robots and other silicon-based life forms. These hypothetical entities, he contended, should not be considered incapable of experiencing pain just because they lack human neurochemistry
Neurochemistry is the study of chemicals, including neurotransmitters and other molecules such as psychopharmaceuticals and neuropeptides, that control and influence the physiology of the nervous system. This particular field within neuroscience ...
. Putnam concluded that type-identity theorists had been making an "ambitious" and "highly implausible" conjecture that could be disproved by one example of multiple realizability. This is sometimes called the "likelihood argument", as it focuses on the claim that multiple realizability is more likely than type-identity theory.
Putnam also formulated an ''a priori
("from the earlier") and ("from the later") are Latin phrases used in philosophy to distinguish types of knowledge, justification, or argument by their reliance on empirical evidence or experience. knowledge is independent from current ...
'' argument in favor of multiple realizability based on what he called "functional isomorphism". He defined the concept in these terms: "Two systems are functionally isomorphic if 'there is a correspondence between the states of one and the states of the other that preserves functional relations'." In the case of computers, two machines are functionally isomorphic if and only if the sequential relations among states in the first exactly mirror the sequential relations among states in the other. Therefore, a computer made of silicon chips and one made of cogs and wheels can be functionally isomorphic but constitutionally diverse. Functional isomorphism implies multiple realizability.
Putnam, Jerry Fodor
Jerry Alan Fodor (; April 22, 1935 – November 29, 2017) was an American philosopher and the author of many crucial works in the fields of philosophy of mind and cognitive science. His writings in these fields laid the groundwork for the modu ...
, and others argued that along with being an effective argument against type-identity theories, multiple realizability implies that any low-level explanation of higher-level mental phenomena is insufficiently abstract and general. Functionalism, which identifies mental kinds with functional kinds that are characterized exclusively in terms of causes and effects, abstracts from the level of microphysics, and therefore seemed to be a better explanation of the relation between mind and body. In fact, there are many functional kinds, including mousetraps and eyes, that are multiply realized at the physical level.
Multiple realizability has been criticized on the grounds that, if it were true, research and experimentation in the neurosciences would be impossible. According to William Bechtel
William Bechtel (born 1951) is a professor of philosophy in the Department of Philosophy and the Science Studies Program at the University of California, San Diego. He was a professor of philosophy at Washington University in St. Louis from 199 ...
and Jennifer Mundale, to be able to conduct such research in the neurosciences, universal consistencies must either exist or be assumed to exist in brain structures. It is the similarity (or homology
Homology may refer to:
Sciences
Biology
*Homology (biology), any characteristic of biological organisms that is derived from a common ancestor
* Sequence homology, biological homology between DNA, RNA, or protein sequences
*Homologous chrom ...
) of brain structures that allows us to generalize across species. If multiple realizability
Multiple realizability, in the philosophy of mind, is the thesis that the same mental property, state, or event can be implemented by different physical properties, states, or events. Philosophers of mind have used multiple realizability to argue ...
were an empirical fact, results from experiments conducted on one species of animal (or one organism) would not be meaningful when generalized to explain the behavior of another species (or organism of the same species). Jaegwon Kim
Jaegwon Kim (September 12, 1934 – November 27, 2019) was a Korean-American philosopher. At the time of his death, Kim was an emeritus professor of philosophy at Brown University. He also taught at several other leading American universities d ...
, David Lewis, Robert Richardson and Patricia Churchland
Patricia Smith Churchland (born 16 July 1943) is a Canadian-American analytic philosopher noted for her contributions to neurophilosophy and the philosophy of mind. She is UC President's Professor of Philosophy Emerita at the University of Calif ...
have also criticized metaphysical realism.
Machine state functionalism
Putnam himself put forth the first formulation of such a functionalist theory. This formulation, now called "machine-state functionalism", was inspired by analogies Putnam and others made between the mind and Turing machine
A Turing machine is a mathematical model of computation describing an abstract machine that manipulates symbols on a strip of tape according to a table of rules. Despite the model's simplicity, it is capable of implementing any computer algori ...
s. The point for functionalism is the nature of the states of the Turing machine. Each state can be defined in terms of its relations to the other states and to the inputs and outputs, and the details of how it accomplishes what it accomplishes and of its material constitution are completely irrelevant. According to machine-state functionalism, the nature of a mental state is just like the nature of a Turing machine state. Just as "state one" simply is the state in which, given a particular input, such-and-such happens, so being in pain is the state which disposes one to cry "ouch", become distracted, wonder what the cause is, and so forth.
Rejection of functionalism
In the late 1980s, Putnam abandoned his adherence to functionalism and other computational theories of mind
Computation is any type of arithmetic or non-arithmetic calculation that follows a well-defined model (e.g., an algorithm).
Mechanical or electronic devices (or, historically, people) that perform computations are known as '' computers''. An e ...
. His change of mind was primarily due to the difficulties computational theories have in explaining certain intuitions with respect to the externalism
Externalism is a group of positions in the philosophy of mind which argues that the conscious mind is not only the result of what is going on inside the nervous system (or the brain), but also what ''occurs'' or ''exists'' outside the subject. It i ...
of mental content. This is illustrated by Putnam's own Twin Earth thought experiment
Twin Earth is a thought experiment proposed by philosopher Hilary Putnam in his papers "Meaning and Reference" (1973) and "The Meaning of 'Meaning (1975). It is meant to serve as an illustration of his argument for semantic externalism, or the ...
(see ''Philosophy of language
In analytic philosophy, philosophy of language investigates the nature of language and the relations between language, language users, and the world. Investigations may include inquiry into the nature of meaning, intentionality, reference, ...
''). In 1988 he also developed a separate argument against functionalism based on Fodor's generalized version of multiple realizability. Asserting that functionalism is really a watered-down identity theory in which mental kinds are identified with functional kinds, Putnam argued that mental kinds may be multiply realizable over functional kinds. The argument for functionalism is that the same mental state could be implemented by the different states of a universal Turing machine
In computer science, a universal Turing machine (UTM) is a Turing machine that can simulate an arbitrary Turing machine on arbitrary input. The universal machine essentially achieves this by reading both the description of the machine to be simu ...
.
Despite Putnam's rejection of functionalism, it has continued to flourish and been developed into numerous versions by Fodor, David Marr, Daniel Dennett
Daniel Clement Dennett III (born March 28, 1942) is an American philosopher, writer, and cognitive scientist whose research centers on the philosophy of mind, philosophy of science, and philosophy of biology, particularly as those fields relat ...
, and David Lewis, among others. Functionalism helped lay the foundations for modern cognitive science and is the dominant theory of mind in philosophy today.
By 2012 Putnam accepted a modification of functionalism called "liberal functionalism". The view holds that "what matters for consciousness and for mental properties generally is the right sort of functional capacities and not the particular matter that subserves those capacities". The specification of these capacities may refer to what goes on outside the organism's "brain", may include intentional idioms, and need not describe a capacity to compute something or other.
Putnam himself formulated one of the main arguments against functionalism: the Twin Earth thought experiment
Twin Earth is a thought experiment proposed by philosopher Hilary Putnam in his papers "Meaning and Reference" (1973) and "The Meaning of 'Meaning (1975). It is meant to serve as an illustration of his argument for semantic externalism, or the ...
. But there have been other criticisms. 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 Mario ...
's Chinese room argument (1980) is a direct attack on the claim that thought can be represented as a set of functions. The thought experiment is designed to show that it is possible to mimic intelligent action with a purely functional system, without any interpretation or understanding. Searle describes a situation in which a person who speaks only English is locked in a room with Chinese symbols in baskets and a rule book in English for moving the symbols around. The person is instructed, by people outside the room, to follow the rule book for sending certain symbols out of the room when given certain symbols. The people outside the room speak Chinese and are communicating with the person inside via the Chinese symbols. According to Searle, it would be absurd to claim that the English speaker inside "knows" Chinese based on these syntactic processes alone. This argument attempts to show that systems that operate merely on syntactic processes cannot realize any semantics
Semantics (from grc, σημαντικός ''sēmantikós'', "significant") is the study of reference, meaning, or truth. The term can be used to refer to subfields of several distinct disciplines, including philosophy
Philosophy (f ...
(meaning) 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 ...
(aboutness). Searle thus attacks the idea that thought can be equated with following a set of syntactic rules and concludes that functionalism is an inadequate theory of the mind. Ned Block
Ned Joel Block (born 1942) is an American philosopher working in philosophy of mind who has made important contributions to the understanding of consciousness and the philosophy of cognitive science. He has been professor of philosophy and psych ...
has advanced several other arguments against functionalism.
Philosophy of language
Semantic externalism
One of Putnam's contributions to philosophy of language
In analytic philosophy, philosophy of language investigates the nature of language and the relations between language, language users, and the world. Investigations may include inquiry into the nature of meaning, intentionality, reference, ...
is his semantic externalism
In the philosophy of language, semantic externalism (the opposite of semantic internalism) is the view that the meaning of a term is determined, in whole or in part, by factors external to the speaker. According to an externalist position, one can ...
, the claim that terms' meanings are determined by factors outside the mind, encapsulated in his slogan that "meaning just ain't in the head". His views on meaning, first laid out in ''Meaning and Reference'' (1973), then in'' The Meaning of "Meaning"'' (1975), use his "Twin Earth" thought experiment to defend this thesis.
Twin Earth shows this, according to Putnam, since on Twin Earth everything is identical to Earth, except that its lakes, rivers and oceans are filled with XYZ rather than H2O. Consequently, when an earthling, Fredrick, uses the Earth-English word "water", it has a different meaning from the Twin Earth-English word "water" when used by his physically identical twin, Frodrick, on Twin Earth. Since Fredrick and Frodrick are physically indistinguishable when they utter their respective words, and since their words have different meanings, meaning cannot be determined solely by what is in their heads. This led Putnam to adopt a version of semantic externalism
In the philosophy of language, semantic externalism (the opposite of semantic internalism) is the view that the meaning of a term is determined, in whole or in part, by factors external to the speaker. According to an externalist position, one can ...
with regard to meaning and mental content. The philosopher of mind and language Donald Davidson, despite his many differences of opinion with Putnam, wrote that semantic externalism constituted an "anti-subjectivist revolution" in philosophers' way of seeing the world. Since Descartes's time, philosophers had been concerned with proving knowledge from the basis of subjective experience. Thanks to Putnam, Saul Kripke
Saul Aaron Kripke (; November 13, 1940 – September 15, 2022) was an American philosopher and logician in the analytic tradition. He was a Distinguished Professor of Philosophy at the Graduate Center of the City University of New York and emerit ...
, Tyler Burge
Tyler Burge (; born 1946) is an American philosopher who is a Distinguished Professor of Philosophy at UCLA. Burge has made contributions to many areas of philosophy, including the philosophy of mind, philosophy of logic, epistemology, philosop ...
and others, Davidson said, philosophy could now take the objective realm for granted and start questioning the alleged "truths" of subjective experience.
Theory of meaning
Along with Kripke, Keith Donnellan
Keith Sedgwick Donnellan (; June 25, 1931 – February 20, 2015) was an American philosopher and Professor of Philosophy (later Professor Emeritus) at the University of California, Los Angeles.
Donnellan contributed to the philosophy of language ...
, and others, Putnam contributed to what is known as the causal theory of reference A causal theory of reference or historical chain theory of reference is a theory of how terms acquire specific referents based on evidence. Such theories have been used to describe many referring terms, particularly logical terms, proper names, and ...
. In particular, he maintained in ''The Meaning of "Meaning"'' that the objects referred to by natural kind
"Natural kind" is an intellectual grouping, or categorizing of things, in a manner that is reflective of the actual world and not just human interests. Some treat it as a classification identifying some structure of truth and reality that exists wh ...
terms—such as "tiger", "water", and "tree"—are the principal elements of the meaning of such terms. There is a linguistic division of labor, analogous to Adam Smith
Adam Smith (baptized 1723 – 17 July 1790) was a Scottish economist and philosopher who was a pioneer in the thinking of political economy and key figure during the Scottish Enlightenment. Seen by some as "The Father of Economics"——— ...
's economic division of labor, according to which such terms have their references fixed by the "experts" in the particular field of science to which the terms belong. So, for example, the reference of the term "lion" is fixed by the community of zoologists, the reference of the term "elm tree" is fixed by the community of botanists, and chemists fix the reference of the term "table salt" as sodium chloride. These referents are considered rigid designator
In modal logic and the philosophy of language, a term is said to be a rigid designator or absolute substantial term when it designates (picks out, denotes, refers to) the same thing in ''all possible worlds'' in which that thing exists. A designat ...
s in the Kripkean sense and are disseminated outward to the linguistic community.
Putnam specifies a finite sequence of elements (a vector) for the description of the meaning of every term in the language. Such a vector consists of four components:
# the object to which the term refers, e.g., the object individuated by the chemical formula H2O;
# a set of typical descriptions of the term, referred to as "the stereotype", e.g., "transparent", "colorless", and "hydrating";
# the semantic indicators that place the object into a general category, e.g., "natural kind" and "liquid";
# the syntactic indicators, e.g., "concrete noun" and "mass noun".
Such a "meaning-vector" provides a description of the reference and use of an expression within a particular linguistic community. It provides the conditions for its correct usage and makes it possible to judge whether a single speaker attributes the appropriate meaning to it or whether its use has changed enough to cause a difference in its meaning. According to Putnam, it is legitimate to speak of a change in the meaning of an expression only if the reference of the term, and not its stereotype, has changed. But since no possible algorithm can determine which aspect—the stereotype or the reference—has changed in a particular case, it is necessary to consider the usage of other expressions of the language. Since there is no limit to the number of such expressions to be considered, Putnam embraced a form of semantic holism
Semantic holism is a theory in the philosophy of language to the effect that a certain part of language, be it a term or a complete sentence, can only be understood through its relations to a (previously understood) larger segment of language. The ...
.
Despite the many changes in his other positions, Putnam consistently adhered to semantic holism. Michael Dummett
Sir Michael Anthony Eardley Dummett (27 June 1925 – 27 December 2011) was an English academic described as "among the most significant British philosophers of the last century and a leading campaigner for racial tolerance and equality." He wa ...
, Jerry Fodor
Jerry Alan Fodor (; April 22, 1935 – November 29, 2017) was an American philosopher and the author of many crucial works in the fields of philosophy of mind and cognitive science. His writings in these fields laid the groundwork for the modu ...
, Ernest Lepore
Ernest or Ernie Lepore (born November 20, 1950) is an American philosopher and cognitive scientist and a professor of philosophy at Rutgers University.
Education and career
Lepore earned his Ph.D. from the University of Minnesota in 1978, and ...
, and others have identified problems with this position. In the first place, they suggest that, if semantic holism is true, it is impossible to understand how a speaker of a language can learn the meaning of an expression in the language. Given the limits of our cognitive abilities, we will never be able to master the whole of the English (or any other) language, even based on the (false) assumption that languages are static and immutable entities. Thus, if one must understand all of a natural language to understand a single word or expression, language learning is simply impossible. Semantic holism also fails to explain how two speakers can mean the same thing when using the same expression, and therefore how any communication is possible between them. Given a sentence ''P'', since Fred and Mary have each mastered different parts of the English language and ''P'' is related in different ways to the sentences in each part, ''P'' means one thing to Fred and something else to Mary. Moreover, if ''P'' derives its meaning from its relations with all the sentences of a language, as soon as the vocabulary of an individual changes by the addition or elimination of a sentence, the totality of relations changes, and therefore also the meaning of ''P''. As this is a common phenomenon, the result is that ''P'' has two different meanings in two different moments in the life of the same person. Consequently, if one accepts the truth of a sentence and then rejects it later on, the meaning of what one rejected and what one accepted are completely different and therefore one cannot change opinions with regard to the same sentences.
Philosophy of mathematics
In the philosophy of mathematics
The philosophy of mathematics is the branch of philosophy that studies the assumptions, foundations, and implications of mathematics. It aims to understand the nature and methods of mathematics, and find out the place of mathematics in people's ...
, Putnam has utilized indispensability arguments to argue for a realist interpretation of mathematics. In his 1971 book ''Philosophy of Logic'', he presented what has since been called the ''locus classicus'' of the Quine–Putnam indispensability argument. The argument, which he attributed to Willard Van Orman Quine
Willard Van Orman Quine (; known to his friends as "Van"; June 25, 1908 – December 25, 2000) was an American philosopher and logician in the analytic tradition, recognized as "one of the most influential philosophers of the twentieth century". ...
, is presented in the book as "quantification over mathematical entities is indispensable for science, both formal and physical; therefore we should accept such quantification; but this commits us to accepting the existence of the mathematical entities in question." According to Charles Parsons, Putnam "very likely" endorsed this version of the argument in his early work, but later came to deny some of the views present in it.
In 1975, Putnam formulated his own indispensability argument based on the no miracles argument in the philosophy of science
Philosophy of science is a branch of philosophy concerned with the foundations, methods, and implications of science. The central questions of this study concern what qualifies as science, the reliability of scientific theories, and the ultim ...
, saying, "I believe that the positive argument for realism n sciencehas an analogue in the case of mathematical realism. Here too, I believe, realism is the only philosophy that doesn't make the success of the science a miracle". According to Putnam, Quine's version of the argument was an argument for the existence of abstract mathematical objects, while Putnam's own argument was simply for a realist interpretation of mathematics, which he believed could be provided by a "mathematics as modal logic
Modal logic is a collection of formal systems developed to represent statements about necessity and possibility. It plays a major role in philosophy of language, epistemology, metaphysics, and natural language semantics. Modal logics extend other ...
" interpretation that need not imply the existence of abstract objects.
Putnam also held the view that mathematics, like physics and other empirical sciences, uses both strict logical proofs and " quasi-empirical" methods. For example, Fermat's Last Theorem
In number theory, Fermat's Last Theorem (sometimes called Fermat's conjecture, especially in older texts) states that no three positive integers , , and satisfy the equation for any integer value of greater than 2. The cases and have been k ...
states that for no integer
An integer is the number zero (), a positive natural number (, , , etc.) or a negative integer with a minus sign (−1, −2, −3, etc.). The negative numbers are the additive inverses of the corresponding positive numbers. In the language ...
are there positive integer values of ''x'', ''y'', and ''z'' such that . Before Andrew Wiles
Sir Andrew John Wiles (born 11 April 1953) is an English mathematician and a Royal Society Research Professor at the University of Oxford, specializing in number theory. He is best known for proving Fermat's Last Theorem, for which he was awar ...
proved this for all in 1995, it had been proved for many values of ''n''. These proofs inspired further research in the area, and formed a quasi-empirical consensus for the theorem. Even though such knowledge is more conjectural than a strictly proved theorem, it was still used in developing other mathematical ideas.
The Quine–Putnam indispensability argument has been extremely influential in the philosophy of mathematics, inspiring continued debate and development of the argument in contemporary philosophy
Contemporary philosophy is the present period in the history of Western philosophy beginning at the early 20th century with the increasing professionalization of the discipline and the rise of analytic and continental philosophy.
The phrase "c ...
of mathematics. According to the ''Stanford Encyclopedia of Philosophy
The ''Stanford Encyclopedia of Philosophy'' (''SEP'') combines an online encyclopedia of philosophy with peer-reviewed publication of original papers in philosophy, freely accessible to Internet users. It is maintained by Stanford University. Eac ...
'', many in the field consider it the best argument for mathematical realism. Prominent counterarguments come from Hartry Field
Hartry H. Field (born November 30, 1946) is an American philosopher. He is Silver Professor of Philosophy at New York University; he is a notable contributor to philosophy of science, philosophy of mathematics, epistemology, and philosophy of min ...
, who argues that mathematics is not indispensable to science, and Penelope Maddy
Penelope Maddy (born 4 July 1950) is an American philosopher. Maddy is Emerita UCI Distinguished Professor of Logic and Philosophy of Science and of Mathematics at the University of California, Irvine. She is well known for her influential work i ...
and Elliott Sober
Elliott R. Sober (born 6 June 1948) is Hans Reichenbach Professor and William F. Vilas Research Professor in the Department of Philosophy at University of Wisconsin–Madison. Sober is noted for his work in philosophy of biology and general phil ...
, who dispute whether we are committed to mathematical realism even if it is indispensable to science.
Mathematics and computer science
Putnam has contributed to scientific fields not directly related to his work in philosophy. As a mathematician, he contributed to the resolution of Hilbert's tenth problem
Hilbert's tenth problem is the tenth on the list of mathematical problems that the German mathematician David Hilbert posed in 1900. It is the challenge to provide a general algorithm which, for any given Diophantine equation (a polynomial equat ...
in mathematics. This problem (now known as Matiyasevich's theorem or the MRDP theorem) was settled by Yuri Matiyasevich
Yuri Vladimirovich Matiyasevich, (russian: Ю́рий Влади́мирович Матиясе́вич; born 2 March 1947 in Leningrad) is a Russian mathematician and computer scientist. He is best known for his negative solution of Hilbert's t ...
in 1970, with a proof that relied heavily on previous research by Putnam, Julia Robinson
Julia Hall Bowman Robinson (December 8, 1919July 30, 1985) was an American mathematician noted for her contributions to the fields of computability theory and computational complexity theory—most notably in decision problems. Her work on Hilber ...
and Martin Davis.
In computability theory
Computability theory, also known as recursion theory, is a branch of mathematical logic, computer science, and the theory of computation that originated in the 1930s with the study of computable functions and Turing degrees. The field has since e ...
, Putnam investigated the structure of the ramified analytical hierarchy
In mathematical logic and descriptive set theory, the analytical hierarchy is an extension of the arithmetical hierarchy. The analytical hierarchy of formulas includes formulas in the language of second-order arithmetic, which can have quantifiers ...
, its connection with the constructible hierarchy
In mathematics, in set theory, the constructible universe (or Gödel's constructible universe), denoted by , is a particular class of sets that can be described entirely in terms of simpler sets. is the union of the constructible hierarchy . It w ...
and its Turing degree
In computer science and mathematical logic the Turing degree (named after Alan Turing) or degree of unsolvability of a set of natural numbers measures the level of algorithmic unsolvability of the set.
Overview
The concept of Turing degree is fund ...
s. He showed that there are many levels of the constructible hierarchy that add no subsets of the integers. Later, with his student George Boolos
George Stephen Boolos (; 4 September 1940 – 27 May 1996) was an American philosopher and a mathematical logician who taught at the Massachusetts Institute of Technology.
Life
Boolos is of Greek-Jewish descent. He graduated with an A.B. i ...
, he showed that the first such "non-index" is the ordinal of ramified analysis (this is the smallest such that is a model of full second-order comprehension). Also, together with a separate paper with his student Richard Boyd
Richard Newell Boyd (May 19, 1942 – February 20, 2021) was an American philosopher, who spent most of his career teaching philosophy at Cornell University where he was Susan Linn Sage Professor of Philosophy and Humane Letters Emeritus. He speci ...
and Gustav Hensel, he demonstrated how the Davis– Mostowski–Kleene
Stephen Cole Kleene ( ; January 5, 1909 – January 25, 1994) was an American mathematician. One of the students of Alonzo Church, Kleene, along with Rózsa Péter, Alan Turing, Emil Post, and others, is best known as a founder of the branch of ...
hyperarithmetical hierarchy of arithmetical degrees can be naturally extended up to .
In computer science
Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical discipli ...
, Putnam is known for the Davis–Putnam algorithm The Davis–Putnam algorithm was developed by Martin Davis and Hilary Putnam for checking the validity of a first-order logic formula using a resolution-based decision procedure for propositional logic. Since the set of valid first-order formulas ...
for the Boolean satisfiability problem
In logic and computer science, the Boolean satisfiability problem (sometimes called propositional satisfiability problem and abbreviated SATISFIABILITY, SAT or B-SAT) is the problem of determining if there exists an interpretation that satisfie ...
(SAT), developed with Martin Davis in 1960. The algorithm finds whether there is a set of true or false values that satisfies a given Boolean expression
In computer science, a Boolean expression is an expression used in programming languages that produces a Boolean value when evaluated. A Boolean value is either true or false. A Boolean expression may be composed of a combination of the Boolean con ...
so that the entire expression becomes true. In 1962, they further refined the algorithm with the help of George Logemann and Donald W. Loveland. It became known as the DPLL algorithm
In logic and computer science, the Davis–Putnam–Logemann–Loveland (DPLL) algorithm is a complete, backtracking-based search algorithm for deciding the satisfiability of propositional logic formulae in conjunctive normal form, i.e. for solvi ...
. It is efficient and still forms the basis of most complete SAT solvers.
Epistemology
In epistemology
Epistemology (; ), or the theory of knowledge, is the branch of philosophy concerned with knowledge. Epistemology is considered a major subfield of philosophy, along with other major subfields such as ethics, logic, and metaphysics.
Episte ...
, Putnam is known for his argument against skeptical scenarios based on the "brain in a vat
In philosophy, the brain in a vat (BIV) is a scenario used in a variety of thought experiments intended to draw out certain features of human conceptions of knowledge, reality, truth, mind, consciousness, and meaning. It is a modern incarna ...
" thought experiment (a modernized version of Descartes's evil demon
The evil demon, also known as Descartes' demon, malicious demon and evil genius, is an epistemological concept that features prominently in Cartesian philosophy. In the first of his 1641 ''Meditations on First Philosophy'', Descartes imagines ...
hypothesis). The argument is that one cannot coherently suspect that one is a disembodied "brain in a vat" placed there by some "mad scientist
The mad scientist (also mad doctor or mad professor) is a stock character of a scientist who is perceived as " mad, bad and dangerous to know" or "insane" owing to a combination of unusual or unsettling personality traits and the unabashedly amb ...
".
This follows from the causal theory of reference. Words always refer to the kinds of things they were coined to refer to, the kinds of things their user, or the user's ancestors, experienced. So, if some person, Mary, is a "brain in a vat", whose every experience is received through wiring and other gadgetry created by the mad scientist, then Mary's idea of a brain does not refer to a real brain, since she and her linguistic community have never encountered such a thing. To her a brain is actually an image fed to her through the wiring. Nor does her idea of a vat refer to a real vat. So if, as a brain in a vat, she says, "I'm a brain in a vat", she is actually saying, "I'm a brain-image in a vat-image", which is incoherent. On the other hand, if she is not a brain in a vat, then saying that she is a brain in a vat is still incoherent, because she actually means the opposite. This is a form of epistemological externalism
Externalism is a group of positions in the philosophy of mind which argues that the conscious mind is not only the result of what is going on inside the nervous system (or the brain), but also what ''occurs'' or ''exists'' outside the subject. It i ...
: knowledge or justification depends on factors outside the mind and is not solely determined internally.
Putnam has clarified that his real target in this argument was never skepticism, but metaphysical realism, which he thought implied such skeptical scenarios were possible. Since realism of this kind assumes the existence of a gap between how one conceives the world and the way the world really is, skeptical scenarios such as this one (or Descartes's evil demon) present a formidable challenge. By arguing that such a scenario is impossible, Putnam attempts to show that this notion of a gap between one's concept of the world and the way it is is absurd. One cannot have a "God's-eye" view of reality. One is limited to one's conceptual schemes, and metaphysical realism is therefore false.
Putnam's brain in a vat
In philosophy, the brain in a vat (BIV) is a scenario used in a variety of thought experiments intended to draw out certain features of human conceptions of knowledge, reality, truth, mind, consciousness, and meaning. It is a modern incarna ...
argument has been criticized. Crispin Wright
Crispin James Garth Wright (; born 21 December 1942) is a British philosopher, who has written on neo-Fregean (neo-logicist) philosophy of mathematics, Wittgenstein's later philosophy, and on issues related to truth, realism, cognitivism, skep ...
argues that Putnam's formulation of the brain-in-a-vat scenario is too narrow to refute global skepticism. The possibility that one is a recently disembodied brain in a vat is not undermined by semantic externalism. If a person has lived her entire life outside the vat—speaking the English language and interacting normally with the outside world—prior to her "envatment" by a mad scientist, when she wakes up inside the vat, her words and thoughts (e.g., "tree" and "grass") will still refer to the objects or events in the external world that they referred to before her envatment.
Metaphilosophy and ontology
In the late 1970s and the 1980s, stimulated by results from mathematical logic and by some of Quine's ideas, Putnam abandoned his long-standing defense of metaphysical realism—the view that the categories and structures of the external world are both causally and ontologically independent of the conceptualizations of the human mind—and adopted a rather different view, which he called "internal realism" or "pragmatic realism". Internal realism is the view that, although the world may be ''causally'' independent of the human mind, the world's structure—its division into kinds, individuals and categories—is a function of the human mind, and hence the world is not ''ontologically'' independent. The general idea is influenced by Immanuel Kant
Immanuel Kant (, , ; 22 April 1724 – 12 February 1804) was a German philosopher and one of the central Enlightenment thinkers. Born in Königsberg, Kant's comprehensive and systematic works in epistemology, metaphysics, ethics, and ...
's idea of the dependence of our knowledge of the world on the categories of thought.
According to Putnam, the problem with metaphysical realism is that it fails to explain the possibility of reference and truth. According to the metaphysical realist, our concepts and categories refer because they match up in some mysterious manner with the categories, kinds and individuals inherent in the external world. But how is it possible that the world "carves up" into certain structures and categories, the mind carves up the world into its own categories and structures, and the two carvings perfectly coincide? The answer must be that the world does not come pre-structured but that the human mind and its conceptual schemes impose structure on it. In ''Reason, Truth, and History'', Putnam identified truth with what he termed "idealized rational acceptability." The theory is that a belief is true if it would be accepted by anyone under ideal epistemic conditions.
Nelson Goodman
Henry Nelson Goodman (7 August 1906 – 25 November 1998) was an American philosopher, known for his work on counterfactuals, mereology, the problem of induction, irrealism, and aesthetics.
Life and career
Goodman was born in Somerville, Mas ...
formulated a similar notion in ''Fact, Fiction and Forecast'' (1956). "We have come to think of the actual as one among many possible worlds. We need to repaint that picture. All possible worlds lie within the actual one", Goodman wrote. Putnam rejected this form of social constructivism
Social constructivism is a sociological theory of knowledge according to which human development is socially situated and knowledge is constructed through interaction with others.
Like social constructionism, social constructivism states th ...
, but retained the idea that there can be many correct descriptions of reality. None of these descriptions can be scientifically proven to be the "one, true" description of the world. He thus accepted "conceptual relativity"—the view that it may be a matter of choice or convention, e.g., whether mereological sums exist, or whether spacetime points are individuals or mere limits.
Curtis Brown has criticized Putnam's internal realism as a disguised form of subjective idealism
In philosophy, the term idealism identifies and describes metaphysical perspectives which assert that reality is indistinguishable and inseparable from perception and understanding; that reality is a mental construct closely connected to ide ...
, in which case it is subject to the traditional arguments against that position. In particular, it falls into the trap of solipsism
Solipsism (; ) is the philosophical idea that only one's mind is sure to exist. As an epistemological position, solipsism holds that knowledge of anything outside one's own mind is unsure; the external world and other minds cannot be known an ...
. That is, if existence depends on experience, as subjective idealism maintains, and if one's consciousness ceased to exist, then the rest of the universe would also cease to exist. In his reply to Simon Blackburn
Simon Blackburn (born 12 July 1944) is an English academic philosopher known for his work in metaethics, where he defends quasi-realism, and in the philosophy of language; more recently, he has gained a large general audience from his effort ...
in the volume ''Reading Putnam'', Putnam renounced internal realism because it assumed a "cognitive interface" model of the relation between the mind and the world. Under the increasing influence of William James
William James (January 11, 1842 – August 26, 1910) was an American philosopher, historian, and psychologist, and the first educator to offer a psychology course in the United States.
James is considered to be a leading thinker of the lat ...
and the pragmatists
Pragmatism is a philosophical tradition that considers words and thought as tools and instruments for prediction, problem solving, and action, and rejects the idea that the function of thought is to describe, represent, or mirror reality. ...
, he adopted a direct realist view of this relation. Although he abandoned internal realism, Putnam still resisted the idea that any given thing or system of things can be described in exactly one complete and correct way. He came to accept metaphysical realism in a broader sense, rejecting all forms of verificationism
Verificationism, also known as the verification principle or the verifiability criterion of meaning, is the philosophical doctrine which maintains that only statements that are empirically verifiable (i.e. verifiable through the senses) are cogniti ...
and all talk of our "making" the world.
In the philosophy of perception
The philosophy of perception is concerned with the nature of perceptual experience and the status of perceptual data, in particular how they relate to beliefs about, or knowledge of, the world.cf. http://plato.stanford.edu/entries/perception-epi ...
, Putnam came to endorse direct realism, according to which perceptual experiences directly present one with the external world. He once further held that there are no mental representations, sense data
The theory of sense data is a view in the philosophy of perception, popularly held in the early 20th century by philosophers such as Bertrand Russell, C. D. Broad, H. H. Price, A. J. Ayer, and G. E. Moore. Sense data are taken to be mind-depend ...
, or other intermediaries between the mind and the world. By 2012, however, he rejected this commitment in favor of "transactionalism
Transactionalism is a pragmatic philosophical approach to how we are known, maintain health and relationships, and satisfy our goals for money and career through ambitious ecologies. It involves the study and accurate thinking required to plan a ...
", a view that accepts both that perceptual experiences are world-involving transactions, and that these transactions are functionally describable (provided that worldly items and intentional states may be referred to in the specification of the function). Such transactions can further involve qualia
In philosophy of mind, qualia ( or ; singular form: quale) are defined as individual instances of subjective, conscious experience. The term ''qualia'' derives from the Latin neuter plural form (''qualia'') of the Latin adjective '' quālis'' () ...
.
Quantum mechanics
During his career, Putnam espoused various positions on the interpretation of quantum mechanics
An interpretation of quantum mechanics is an attempt to explain how the mathematical theory of quantum mechanics might correspond to experienced reality. Although quantum mechanics has held up to rigorous and extremely precise tests in an extraord ...
. In the 1960s and 1970s, he contributed to the quantum logic
In the mathematical study of logic and the physical analysis of quantum foundations, quantum logic is a set of rules for manipulation of propositions inspired by the structure of quantum theory. The field takes as its starting point an observ ...
tradition, holding that the way to resolve quantum theory's apparent paradoxes is to modify the logical rules by which propositions' truth values are deduced. Putnam's first foray into this topic was "A Philosopher Looks at Quantum Mechanics" in 1965, followed by his 1969 essay " Is Logic Empirical?". He advanced different versions of quantum logic over the years, and eventually turned away from it in the 1990s, due to critiques by Nancy Cartwright
Nancy Cartwright (born October 25, 1957) is an American actress. She is the long-time voice of Bart Simpson on the animated television series ''The Simpsons'', for which she has received a Primetime Emmy Award for Outstanding Voice-Over Perform ...
, Michael Redhead
Michael Logan Gonne Redhead (30 December 1929 – 31 August 2020) was a British academic and philosopher of physics.
Biography
Redhead was born on 30 December 1929 in London and educated there at Westminster School.
Redhead was Centennial ...
, and others. In 2005, he wrote that he rejected the many-worlds interpretation
The many-worlds interpretation (MWI) is an interpretation of quantum mechanics that asserts that the universal wavefunction is objectively real, and that there is no wave function collapse. This implies that all possible outcomes of quantum me ...
because he could see no way for it to yield meaningful probabilities. He found both de Broglie–Bohm theory
The de Broglie–Bohm theory, also known as the ''pilot wave theory'', Bohmian mechanics, Bohm's interpretation, and the causal interpretation, is an interpretation of quantum mechanics. In addition to the wavefunction, it also postulates an act ...
and the spontaneous collapse theory of Ghirardi, Rimini, and Weber to be promising, yet also dissatisfying, since it was not clear that either could be made fully consistent with special relativity
In physics, the special theory of relativity, or special relativity for short, is a scientific theory regarding the relationship between space and time. In Albert Einstein's original treatment, the theory is based on two postulates:
# The laws o ...
's symmetry requirements.
Neopragmatism and Wittgenstein
In the mid-1970s, Putnam became increasingly disillusioned with what he perceived as modern analytic philosophy
Analytic philosophy is a branch and tradition of philosophy using analysis, popular in the Western world and particularly the Anglosphere, which began around the turn of the 20th century in the contemporary era in the United Kingdom, United Sta ...
's "scientism
Scientism is the opinion that science and the scientific method are the best or only way to render truth about the world and reality.
While the term was defined originally to mean "methods and attitudes typical of or attributed to natural scientis ...
" and focus on metaphysics over ethics and everyday concerns. He also became convinced by his readings of James and John Dewey
John Dewey (; October 20, 1859 – June 1, 1952) was an American philosopher, psychologist, and educational reformer whose ideas have been influential in education and social reform. He was one of the most prominent American scholars in the f ...
that there is no fact–value dichotomy; that is, normative
Normative generally means relating to an evaluative standard. Normativity is the phenomenon in human societies of designating some actions or outcomes as good, desirable, or permissible, and others as bad, undesirable, or impermissible. A norm in ...
(e.g., ethical and aesthetic) judgments often have a factual basis, while scientific judgments have a normative element. For a time, under Ludwig Wittgenstein
Ludwig Josef Johann Wittgenstein ( ; ; 26 April 1889 – 29 April 1951) was an Austrian-British philosopher who worked primarily in logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language. He is considere ...
's influence, Putnam adopted a pluralist view of philosophy itself and came to view most philosophical problems as no more than conceptual or linguistic confusions philosophers created by using ordinary language out of context. A book of articles on pragmatism by Ruth Anna Putnam and Hilary Putnam, ''Pragmatism as a Way of Life: The Lasting Legacy of William James and John Dewey'', edited by David Macarthur
David Macarthur is an Australian philosopher and Professor of Philosophy at the University of Sydney who works primarily on skepticism, metaphysical quietism, pragmatism, liberal naturalism and philosophy of art (especially film, photography and a ...
, was published in 2017.
Many of Putnam's last works addressed the concerns of ordinary people, particularly social problems. For example, he wrote about the nature of democracy
Democracy (From grc, δημοκρατία, dēmokratía, ''dēmos'' 'people' and ''kratos'' 'rule') is a form of government in which the people have the authority to deliberate and decide legislation (" direct democracy"), or to choose gov ...
, social justice
Social justice is justice in terms of the distribution of wealth, opportunities, and privileges within a society. In Western and Asian cultures, the concept of social justice has often referred to the process of ensuring that individuals fu ...
and religion
Religion is usually defined as a social- cultural system of designated behaviors and practices, morals, beliefs, worldviews, texts, sanctified places, prophecies, ethics, or organizations, that generally relates humanity to supernatural, ...
. He also discussed Jürgen Habermas
Jürgen Habermas (, ; ; born 18 June 1929) is a German social theorist in the tradition of critical theory and pragmatism. His work addresses communicative rationality and the public sphere.
Associated with the Frankfurt School, Habermas's wor ...
's ideas, and wrote articles influenced by continental philosophy
Continental philosophy is a term used to describe some philosophers and philosophical traditions that do not fall under the umbrella of analytic philosophy. However, there is no academic consensus on the definition of continental philosophy. Pri ...
.
Major works and bibliography
Vincent C. Müller compiled a detailed bibliography of Putnam's writings, citing 16 books and 198 articles, published in 1993 in PhilPapers
PhilPapers is an interactive academic database of journal articles in philosophy. It is maintained by the Centre for Digital Philosophy at the University of Western Ontario, and as of 2022, it has "394,867 registered users, including the majorit ...
.
* 2nd ed., Cambridge: Cambridge University Press, 1983.
*
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* 2nd. ed., 1985 paperback:
* 2003 paperback:
*
* 2004 paperback:
* 2002 paperback:
*
*
*
*
*
*
*
*
* Based on the Gifford Lectures
The Gifford Lectures () are an annual series of lectures which were established in 1887 by the will of Adam Gifford, Lord Gifford. Their purpose is to "promote and diffuse the study of natural theology in the widest sense of the term – in o ...
that Putnam delivered at the University of St Andrews
(Aien aristeuein)
, motto_lang = grc
, mottoeng = Ever to ExcelorEver to be the Best
, established =
, type = Public research university
Ancient university
, endowment ...
in 1990 and 1991.
*
*
*
*
*
*
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*
See also
* American philosophy
American philosophy is the activity, corpus, and tradition of philosophers affiliated with the United States. The ''Internet Encyclopedia of Philosophy'' notes that while it lacks a "core of defining features, American Philosophy can nevert ...
* List of American philosophers
This is a list of American philosophers; of philosophers who are either from, or spent many productive years of their lives in the United States.
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References
Further reading
*
*
External links
* Hilary Putnam's blog
Sardonic comment
as stated by Putnam in "Hookway and Quine", ''Transactions of the Charles S. Peirce Society'', vol. 51, no. 4, 2015, pp. 495–507.
*
*
*
''London Review of Books'' contributor page
Hilary Putnam: On Mind, Meaning and Reality
, Interview by Josh Harlan, ''The Harvard Review of Philosophy
''The Harvard Review of Philosophy'' is an annual peer-reviewed academic journal of philosophy edited by a student collective at Harvard University.Scanlon, Thomas (2002) "Foreword" ''In'' Upham, S. Phineas, ''Philosophers in Conversation: Intervi ...
'', Spring 1992.
"To Think with Integrity"
, Hilary Putnam's Farewell Lecture, ''The Harvard Review of Philosophy'', Spring 2000.
*
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