Giuseppe Peano (; ; 27 August 1858 – 20 April 1932) was an Italian
mathematician
A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...
and
glottologist. The author of over 200 books and papers, he was a founder of
mathematical logic
Mathematical logic is the study of Logic#Formal logic, formal logic within mathematics. Major subareas include model theory, proof theory, set theory, and recursion theory (also known as computability theory). Research in mathematical logic com ...
and
set theory
Set theory is the branch of mathematical logic that studies Set (mathematics), sets, which can be informally described as collections of objects. Although objects of any kind can be collected into a set, set theory – as a branch of mathema ...
, to which he contributed much
notation
In linguistics and semiotics, a notation system is a system of graphics or symbols, Character_(symbol), characters and abbreviated Expression (language), expressions, used (for example) in Artistic disciplines, artistic and scientific disciplines ...
. The standard
axiomatization of the
natural number
In mathematics, the natural numbers are the numbers 0, 1, 2, 3, and so on, possibly excluding 0. Some start counting with 0, defining the natural numbers as the non-negative integers , while others start with 1, defining them as the positive in ...
s is named the
Peano axioms
In mathematical logic, the Peano axioms (, ), also known as the Dedekind–Peano axioms or the Peano postulates, are axioms for the natural numbers presented by the 19th-century Italian mathematician Giuseppe Peano. These axioms have been used nea ...
in his honor. As part of this effort, he made key contributions to the modern rigorous and systematic treatment of the method of
mathematical induction
Mathematical induction is a method for mathematical proof, proving that a statement P(n) is true for every natural number n, that is, that the infinitely many cases P(0), P(1), P(2), P(3), \dots all hold. This is done by first proving a ...
. He spent most of his career teaching mathematics at the
University of Turin
The University of Turin (Italian language, Italian: ''Università degli Studi di Torino'', UNITO) is a public university, public research university in the city of Turin, in the Piedmont (Italy), Piedmont region of Italy. It is one of the List ...
. He also created an international auxiliary language,
Latino sine flexione
Latino sine flexione ("Latin without inflections"), Interlingua de Academia pro Interlingua (IL de ApI) or Peano's Interlingua (abbreviated as IL) is an international auxiliary language compiled by the Academia pro Interlingua under the chairmansh ...
("Latin without inflections"), which is a simplified version of Classical Latin. Most of his books and papers are in Latino sine flexione, while others are in Italian.
Biography
Peano was born and raised on a farm at Spinetta, a hamlet now belonging to
Cuneo
Cuneo (; ; ; ) is a city and in Piedmont, Italy, the capital of the province of Cuneo, the fourth largest of Italy’s provinces by area.
It is located at 550 metres (1,804 ft) in the south-west of Piedmont, at the confluence of the ri ...
,
Piedmont
Piedmont ( ; ; ) is one of the 20 regions of Italy, located in the northwest Italy, Northwest of the country. It borders the Liguria region to the south, the Lombardy and Emilia-Romagna regions to the east, and the Aosta Valley region to the ...
,
Italy
Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...
. He attended the
Liceo classico Cavour
Liceo Ginnasio statale "Camillo Benso di Cavour" is the oldest Liceo classico in Turin and one among the oldest and most prominent high schools in Italy, for pupils aged 14 to 19. It was transferred to its present location in 1931.
History
It was ...
in
Turin
Turin ( , ; ; , then ) is a city and an important business and cultural centre in northern Italy. It is the capital city of Piedmont and of the Metropolitan City of Turin, and was the first Italian capital from 1861 to 1865. The city is main ...
, and enrolled at the
University of Turin
The University of Turin (Italian language, Italian: ''Università degli Studi di Torino'', UNITO) is a public university, public research university in the city of Turin, in the Piedmont (Italy), Piedmont region of Italy. It is one of the List ...
in 1876, graduating in 1880 with high honours, after which the University employed him to assist first
Enrico D'Ovidio, and then
Angelo Genocchi
Angelo Genocchi (5 March 1817 – 7 March 1889) was an Italian mathematician who specialized in number theory. He worked with Giuseppe Peano. The Genocchi numbers are named after him.
Life and Works
Angelo Genocchi was born and grew up and ...
, the Chair of
calculus
Calculus is the mathematics, mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizations of arithmetic operations.
Originally called infinitesimal calculus or "the ...
. Due to Genocchi's poor health, Peano took over the teaching of calculus course within two years. His first major work, a textbook on calculus entitled ''Calcolo differenziale, e principii di calcolo integrale'', was published in 1884 and was credited to Genocchi. A few years later, Peano published his first book dealing with mathematical logic. Here the modern symbols for the
union and
intersection
In mathematics, the intersection of two or more objects is another object consisting of everything that is contained in all of the objects simultaneously. For example, in Euclidean geometry, when two lines in a plane are not parallel, their ...
of sets appeared for the first time.
Peano joined
Freemasonry
Freemasonry (sometimes spelled Free-Masonry) consists of fraternal groups that trace their origins to the medieval guilds of stonemasons. Freemasonry is the oldest secular fraternity in the world and among the oldest still-existing organizati ...
. It is not known where he was initiated, but on December 24, 1885, he was affiliated as
Master in the "
Dante Alighieri
Dante Alighieri (; most likely baptized Durante di Alighiero degli Alighieri; – September 14, 1321), widely known mononymously as Dante, was an Italian Italian poetry, poet, writer, and philosopher. His ''Divine Comedy'', originally called ...
" Masonic Lodge in Turin. Here he knew the Italian socialist and freemason Giovanni Lerda (1853-1927), a close collaborator of
Cesare Lombroso
Cesare Lombroso ( , ; ; born Ezechia Marco Lombroso; 6 November 1835 – 19 October 1909) was an Italian eugenicist, criminologist, phrenologist, physician, and founder of the Italian school of criminology. He is considered the founder of m ...
.

In 1887, Peano married Carola Crosio, the daughter of the Turin-based painter
Luigi Crosio, known for painting the ''
Refugium Peccatorum Madonna
Madonna Louise Ciccone ( ; born August 16, 1958) is an American singer, songwriter, record producer, and actress. Referred to as the "Queen of Pop", she has been recognized for her continual reinvention and versatility in music production, ...
''. In 1886, he began teaching concurrently at the
Royal Military Academy, and was promoted to Professor First Class in 1889. In that year he published the
Peano axioms
In mathematical logic, the Peano axioms (, ), also known as the Dedekind–Peano axioms or the Peano postulates, are axioms for the natural numbers presented by the 19th-century Italian mathematician Giuseppe Peano. These axioms have been used nea ...
, a formal foundation for the collection of
natural number
In mathematics, the natural numbers are the numbers 0, 1, 2, 3, and so on, possibly excluding 0. Some start counting with 0, defining the natural numbers as the non-negative integers , while others start with 1, defining them as the positive in ...
s. The next year, the University of Turin also granted him his full professorship. The
Peano curve was published in 1890 as the first example of a
space-filling curve
In mathematical analysis, a space-filling curve is a curve whose Range of a function, range reaches every point in a higher dimensional region, typically the unit square (or more generally an ''n''-dimensional unit hypercube). Because Giuseppe Pea ...
which demonstrated that the unit interval and the unit square have the same
cardinality
The thumb is the first digit of the hand, next to the index finger. When a person is standing in the medical anatomical position (where the palm is facing to the front), the thumb is the outermost digit. The Medical Latin English noun for thum ...
. Today it is understood to be an early example of what is known as a
fractal
In mathematics, a fractal is a Shape, geometric shape containing detailed structure at arbitrarily small scales, usually having a fractal dimension strictly exceeding the topological dimension. Many fractals appear similar at various scale ...
.
In 1890 Peano founded the journal ''Rivista di Matematica'', which published its first issue in January 1891. In 1891 Peano started the
Formulario Project. It was to be an "Encyclopedia of Mathematics", containing all known formulae and theorems of mathematical science using a standard notation invented by Peano. In 1897, the first
International Congress of Mathematicians
The International Congress of Mathematicians (ICM) is the largest conference for the topic of mathematics. It meets once every four years, hosted by the International Mathematical Union (IMU).
The Fields Medals, the IMU Abacus Medal (known before ...
was held in
Zürich
Zurich (; ) is the list of cities in Switzerland, largest city in Switzerland and the capital of the canton of Zurich. It is in north-central Switzerland, at the northwestern tip of Lake Zurich. , the municipality had 448,664 inhabitants. The ...
. Peano was a key participant, presenting a paper on mathematical logic. He also started to become increasingly occupied with ''Formulario'' to the detriment of his other work.
In 1898 he presented a note to the Academy about
binary numeration and its ability to be used to represent the sounds of languages. He also became so frustrated with publishing delays (due to his demand that formulae be printed on one line) that he purchased a printing press.
Paris was the venue for the Second
International Congress of Mathematicians
The International Congress of Mathematicians (ICM) is the largest conference for the topic of mathematics. It meets once every four years, hosted by the International Mathematical Union (IMU).
The Fields Medals, the IMU Abacus Medal (known before ...
in 1900. The conference was preceded by the First
International Conference of Philosophy where Peano was a member of the patronage committee. He presented a paper which posed the question of correctly formed definitions in mathematics, ''i.e.'' "how do you define a definition?". This became one of Peano's main philosophical interests for the rest of his life. At the conference, Peano met
Bertrand Russell
Bertrand Arthur William Russell, 3rd Earl Russell, (18 May 1872 – 2 February 1970) was a British philosopher, logician, mathematician, and public intellectual. He had influence on mathematics, logic, set theory, and various areas of analytic ...
and gave him a copy of ''Formulario''. Russell was struck by Peano's innovative logical symbols and after the conference, he retired to the country "to study quietly every word written by him or his disciples".
Peano's students
Mario Pieri
Mario Pieri (22 June 1860 – 1 March 1913) was an Italian mathematician who is known for his work on foundations of geometry.
Biography
Pieri was born in Lucca, Italy, the son of Pellegrino Pieri and Ermina Luporini. Pellegrino was a lawyer. Pie ...
and
Alessandro Padoa also had papers presented at the philosophy congress. For the mathematical congress, Peano did not speak, but Padoa's memorable presentation has been frequently recalled. A resolution calling for the formation of an "international auxiliary language" to facilitate the spread of mathematical (and commercial) ideas, was proposed; Peano fully supported it.
By 1901, Peano was at the peak of his mathematical career. He had made advances in the areas of
analysis
Analysis (: analyses) is the process of breaking a complex topic or substance into smaller parts in order to gain a better understanding of it. The technique has been applied in the study of mathematics and logic since before Aristotle (38 ...
, foundations and logic, made many contributions to the teaching of calculus and also contributed to the fields of
differential equations and
vector analysis
Vector calculus or vector analysis is a branch of mathematics concerned with the differentiation and integration of vector fields, primarily in three-dimensional Euclidean space, \mathbb^3. The term ''vector calculus'' is sometimes used as a ...
. Peano played a key role in the
axiomatization of mathematics and was a leading pioneer in the development of mathematical logic. Peano had by this stage become heavily involved with the ''Formulario'' project and his teaching began to suffer. In fact, he became so determined to teach his new mathematical symbols that the calculus in his course was neglected. As a result, he was dismissed from the Royal Military Academy but retained his post at Turin University.
In 1903 Peano announced his work on an international auxiliary language called ''
Latino sine flexione
Latino sine flexione ("Latin without inflections"), Interlingua de Academia pro Interlingua (IL de ApI) or Peano's Interlingua (abbreviated as IL) is an international auxiliary language compiled by the Academia pro Interlingua under the chairmansh ...
'' ("
Latin
Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
without inflexion," later called Interlingua, and the precursor of the
Interlingua
Interlingua (, ) is an international auxiliary language (IAL) developed between 1937 and 1951 by the American International Auxiliary Language Association (IALA). It is a constructed language of the "naturalistic" variety, whose vocabulary, ...
of the
IALA). This was an important project for him (along with finding contributors for 'Formulario'). The idea was to use Latin vocabulary, since this was widely known, but simplify the grammar as much as possible and remove all irregular and anomalous forms to make it easier to learn. On 3 January 1908, he read a paper to the ''Academia delle Scienze di Torino'' in which he started speaking in Latin and, as he described each simplification, introduced it into his speech so that by the end he was talking in his new language.
The year 1908 was important for Peano. The fifth and final edition of the ''Formulario'' project, titled ''
Formulario mathematico
''Formulario Mathematico'' (Latino sine flexione: ''Formulary for Mathematics'') is a book by Giuseppe Peano which expresses fundamental theorems of mathematics in a Symbolic language (mathematics), symbolic language developed by Peano. The autho ...
'', was published. It contained 4200 formulae and theorems, all completely stated and most of them proved. The book received little attention since much of the content was dated by this time. However, it remains a significant contribution to mathematical literature. The comments and examples were written in ''Latino sine flexione''.
Also in 1908, Peano took over the chair of higher analysis at Turin (this appointment was to last for only two years). He was elected the director of ''
Academia pro Interlingua
The Academia pro Interlingua was an organization dedicated to the promotion of international auxiliary languages, and is associated in particular with Giuseppe Peano's language Latino sine flexione (Latin without inflections).
The ''Academia'' wa ...
''. Having previously created
Idiom Neutral
Idiom Neutral is an international auxiliary language, published in 1902 by the International Academy of the Universal Language () under the leadership of Waldemar Rosenberger, a St. Petersburg engineer.
History
The Academy had its origin a ...
, the Academy effectively chose to abandon it in favour of Peano's
Latino sine flexione
Latino sine flexione ("Latin without inflections"), Interlingua de Academia pro Interlingua (IL de ApI) or Peano's Interlingua (abbreviated as IL) is an international auxiliary language compiled by the Academia pro Interlingua under the chairmansh ...
.
After his mother died in 1910, Peano divided his time between teaching, working on texts aimed for secondary schooling including a dictionary of mathematics, and developing and promoting his and other
auxiliary languages, becoming a revered member of the international auxiliary language movement. He used his membership of the ''
Accademia dei Lincei
The (; literally the "Academy of the Lynx-Eyed"), anglicised as the Lincean Academy, is one of the oldest and most prestigious European scientific institutions, located at the Palazzo Corsini on the Via della Lungara in Rome, Italy. Founded in ...
'' to present papers written by friends and colleagues who were not members (the Accademia recorded and published all presented papers given in sessions).
During the years 1913–1918, Peano published several papers that dealt with the remainder term for various
numerical quadrature formulas, and introduced the
Peano kernel.
In 1925 Peano switched Chairs unofficially from Infinitesimal Calculus to Complementary Mathematics, a field which better suited his current style of mathematics. This move became official in 1931. Giuseppe Peano continued teaching at Turin University until the day before he died when he suffered a fatal
heart attack
A myocardial infarction (MI), commonly known as a heart attack, occurs when Ischemia, blood flow decreases or stops in one of the coronary arteries of the heart, causing infarction (tissue death) to the heart muscle. The most common symptom ...
.
Milestones and honours received

* 1881: Published first paper.
* 1884: ''Calcolo Differenziale e Principii di Calcolo Integrale''.
* 1887: ''Applicazioni Geometriche del Calcolo Infinitesimale''.
* 1889: Appointed Professor First Class at the Royal Military Academy.
* 1889: ''Arithmetices principia: nova methodo exposita.''
* 1890: Appointed Extraordinary Professor of
infinitesimal calculus
Calculus is the mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizations of arithmetic operations.
Originally called infinitesimal calculus or "the calculus of ...
at the
University of Turin
The University of Turin (Italian language, Italian: ''Università degli Studi di Torino'', UNITO) is a public university, public research university in the city of Turin, in the Piedmont (Italy), Piedmont region of Italy. It is one of the List ...
.
* 1891: Made a member of the Academy of Science, Torino.
* 1893: ''Lezioni di Analisi Infinitesimale'', 2 vols.
* 1895: Promoted to Ordinary Professor.
* 1901: Made Knight of the
Order of Saints Maurizio and Lazzaro.
* 1903: Announces ''
Latino sine flexione
Latino sine flexione ("Latin without inflections"), Interlingua de Academia pro Interlingua (IL de ApI) or Peano's Interlingua (abbreviated as IL) is an international auxiliary language compiled by the Academia pro Interlingua under the chairmansh ...
''.
* 1905: Made Knight of the
Order of the Crown of Italy
The Order of the Crown of Italy ( or OCI) was founded as a national order in 1868 by King Victor Emmanuel II of Italy, Vittorio Emanuele II, to commemorate Italian unification, the unification of Italy in 1861. It was awarded in five degrees for ...
. Elected a corresponding member of the
Accademia dei Lincei
The (; literally the "Academy of the Lynx-Eyed"), anglicised as the Lincean Academy, is one of the oldest and most prestigious European scientific institutions, located at the Palazzo Corsini on the Via della Lungara in Rome, Italy. Founded in ...
in Rome, the highest Italian honour for scientists.
* 1908: Fifth and final edition of the ''
Formulario mathematico
''Formulario Mathematico'' (Latino sine flexione: ''Formulary for Mathematics'') is a book by Giuseppe Peano which expresses fundamental theorems of mathematics in a Symbolic language (mathematics), symbolic language developed by Peano. The autho ...
''.
* 1917: Made an Officer of the Crown of Italy.
* 1921: Promoted to Commendatore of the Crown of Italy.
Bibliography
;Peano's writings in English translation
*1889. "The principles of arithmetic, presented by a new method" in
Jean van Heijenoort, 1967. ''A Source Book in Mathematical Logic, 1879–1931''. Harvard Univ. Press: 83–97.
*1973. ''Selected works of Giuseppe Peano''. Kennedy, Hubert C., ed. and transl. With a biographical sketch and bibliography. London: Allen & Unwin.
See also
* ''
Arithmetices principia, nova methodo exposita
The 1889 treatise ''Arithmetices principia, nova methodo exposita'' (''The principles of arithmetic, presented by a new method'') by Giuseppe Peano is widely considered to be a seminal document in mathematical logic and set theory, introducin ...
''
*
Foundations of geometry
Foundations of geometry is the study of geometries as axiomatic systems. There are several sets of axioms which give rise to Euclidean geometry or to non-Euclidean geometry, non-Euclidean geometries. These are fundamental to the study and of hist ...
References
Further reading
* Gillies, Douglas A., 1982. ''Frege, Dedekind, and Peano on the Foundations of Arithmetic''. Assen, Netherlands: Van Gorcum.
*
Ivor Grattan-Guinness
Ivor Owen Grattan-Guinness (23 June 1941 – 12 December 2014) was a historian of mathematics and logic.
Life
Grattan-Guinness was born in Bakewell, England; his father was a mathematics teacher and educational administrator. He gained his ...
, 2000. ''The Search for Mathematical Roots 1870–1940''. Princeton University Press.
* Segre, Michael, 1994. "Peano's Axioms in their Historical Context," ''Archive for History of Exact Sciences'' 48, pp. 201–342.
* Ferreirós, José, 2005. "R. Dedekind, Was sind und was sollen die Zahlen? (1888), G. Peano, Arithmetics Principia, Nova Methodo Exposita (1889)". Pp. 613–626 of ''Landmark Writings in Western Mathematics 1640–1940'', ed. I. Grattan-Guinness. Amsterdam: Elsevier.
External links
*
*
*
*
* Collection of articles on life and mathematics of Peano (1960s to 1980s).
Instituto Pro Latino Sine Flexione
{{DEFAULTSORT:Peano, Giuseppe
1858 births
1932 deaths
People from Cuneo
People from the Kingdom of Sardinia
19th-century Italian mathematicians
20th-century Italian mathematicians
20th-century Italian philosophers
Linear algebraists
Constructed language creators
Knights of the Order of Saints Maurice and Lazarus
University of Turin alumni
Academic staff of the University of Turin
Textbook writers
Historical linguists
Linguists from Italy
19th-century writers in Latin
Latin-language writers from Italy
Italian Freemasons