Probability
Probability is a branch of mathematics and statistics concerning events and numerical descriptions of how likely they are to occur. The probability of an event is a number between 0 and 1; the larger the probability, the more likely an e ...
has a dual aspect: on the one hand the likelihood of
hypotheses
A hypothesis (: hypotheses) is a proposed explanation for a phenomenon. A scientific method, scientific hypothesis must be based on observations and make a testable and reproducible prediction about reality, in a process beginning with an educ ...
given the evidence for them, and on the other hand the behavior of
stochastic processes
In probability theory and related fields, a stochastic () or random process is a mathematical object usually defined as a family of random variables in a probability space, where the index of the family often has the interpretation of time. Stoc ...
such as the throwing of
dice
A die (: dice, sometimes also used as ) is a small, throwable object with marked sides that can rest in multiple positions. Dice are used for generating random values, commonly as part of tabletop games, including dice games, board games, ro ...
or
coins
A coin is a small object, usually round and flat, used primarily as a medium of exchange or legal tender. They are standardized in weight, and produced in large quantities at a mint in order to facilitate trade. They are most often issued by ...
. The study of the former is historically older in, for example,
the law of evidence, while the
mathematical
Mathematics is a field of study that discovers and organizes methods, Mathematical theory, theories and theorems that are developed and Mathematical proof, proved for the needs of empirical sciences and mathematics itself. There are many ar ...
treatment of dice began with the work of
Cardano,
Pascal,
Fermat
Pierre de Fermat (; ; 17 August 1601 – 12 January 1665) was a French mathematician who is given credit for early developments that led to infinitesimal calculus, including his technique of adequality. In particular, he is recognized for his d ...
and
Christiaan Huygens
Christiaan Huygens, Halen, Lord of Zeelhem, ( , ; ; also spelled Huyghens; ; 14 April 1629 – 8 July 1695) was a Dutch mathematician, physicist, engineer, astronomer, and inventor who is regarded as a key figure in the Scientific Revolution ...
between the 16th and 17th century.
Probability deals with random experiments with a known distribution, Statistics deals with inference from the data about the unknown distribution.
Etymology
''Probable'' and ''probability'' and their cognates in other modern languages derive from medieval learned
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 ...
, deriving from
Cicero
Marcus Tullius Cicero ( ; ; 3 January 106 BC – 7 December 43 BC) was a Roman statesman, lawyer, scholar, philosopher, orator, writer and Academic skeptic, who tried to uphold optimate principles during the political crises tha ...
and generally applied to an opinion to mean ''plausible'' or ''generally approved''. The form ''probability'' is from Old French (14 c.) and directly from
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 ...
(nominative ) "credibility, probability," from (see probable).
The mathematical sense of the term is from 1718. In the 18th century, the term ''chance'' was also used in the mathematical sense of "probability" (and probability theory was called ''Doctrine of Chances''). This word is ultimately from Latin , i.e. "a fall, case". The English adjective ''likely'' is of Germanic origin, most likely from Old Norse (Old English had with the same sense), originally meaning "having the appearance of being strong or able" "having the similar appearance or qualities", with a meaning of "probably" recorded mid-15 c. The derived noun ''likelihood'' had a meaning of "similarity, resemblance" but took on a meaning of "probability" from the mid 15th century. The meaning "something likely to be true" is from 1570s.
Origins
Ancient and medieval
law of evidence developed a grading of degrees of proof, credibility,
presumption
In law, a presumption is an "inference of a particular fact". There are two types of presumptions: rebuttable presumptions and irrebuttable (or conclusive) presumptions. A rebuttable presumption will either shift the burden of production (requir ...
s and
half-proof to deal with the uncertainties of evidence in court.
In
Renaissance
The Renaissance ( , ) is a Periodization, period of history and a European cultural movement covering the 15th and 16th centuries. It marked the transition from the Middle Ages to modernity and was characterized by an effort to revive and sur ...
times, betting was discussed in terms of
odds
In probability theory, odds provide a measure of the probability of a particular outcome. Odds are commonly used in gambling and statistics. For example for an event that is 40% probable, one could say that the odds are or
When gambling, o ...
such as "ten to one" and maritime
insurance
Insurance is a means of protection from financial loss in which, in exchange for a fee, a party agrees to compensate another party in the event of a certain loss, damage, or injury. It is a form of risk management, primarily used to protect ...
premiums were estimated based on intuitive risks, but there was no theory on how to calculate such odds or premiums.
The mathematical methods of probability arose in the investigations first of
Gerolamo Cardano
Gerolamo Cardano (; also Girolamo or Geronimo; ; ; 24 September 1501– 21 September 1576) was an Italian polymath whose interests and proficiencies ranged through those of mathematician, physician, biologist, physicist, chemist, astrologer, as ...
in the 1560s (not published until 100 years later), and then in the correspondence
Pierre de Fermat
Pierre de Fermat (; ; 17 August 1601 – 12 January 1665) was a French mathematician who is given credit for early developments that led to infinitesimal calculus, including his technique of adequality. In particular, he is recognized for his d ...
and
Blaise Pascal
Blaise Pascal (19June 162319August 1662) was a French mathematician, physicist, inventor, philosopher, and Catholic Church, Catholic writer.
Pascal was a child prodigy who was educated by his father, a tax collector in Rouen. His earliest ...
(1654) on such questions as the fair division of the stake in an interrupted game of chance.
Christiaan Huygens
Christiaan Huygens, Halen, Lord of Zeelhem, ( , ; ; also spelled Huyghens; ; 14 April 1629 – 8 July 1695) was a Dutch mathematician, physicist, engineer, astronomer, and inventor who is regarded as a key figure in the Scientific Revolution ...
(1657) gave a comprehensive treatment of the subject.
In ancient times there were games played using astragali, or
talus bone
The talus (; Latin for ankle or ankle bone; : tali), talus bone, astragalus (), or ankle bone is one of the group of Foot#Structure, foot bones known as the tarsus (skeleton), tarsus. The tarsus forms the lower part of the ankle joint. It transmit ...
. The
pottery of ancient Greece
Pottery, due to its relative durability, comprises a large part of the archaeological record of ancient Greece, and since there is so much of it (over 100,000 painted vases are recorded in the Corpus vasorum antiquorum), it has exerted a dispro ...
provides evidence to show that the astragali were tossed into a circle drawn on the floor, much like playing marbles. In
Egypt
Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northe ...
, excavators of tombs found a game they called "Hounds and Jackals", which closely resembles the modern game
snakes and ladders. According to
Pausanias,
Palamedes invented dice during the Trojan wars, although their true origin is uncertain. The first dice game mentioned in literature of the Christian era was called
hazard
A hazard is a potential source of harm. Substances, events, or circumstances can constitute hazards when their nature would potentially allow them to cause damage to health, life, property, or any other interest of value. The probability of that ...
. Played with two or three dice, it was probably brought to Europe by the knights returning from the Crusades.
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 ...
(1265–1321) mentions this game. A commenter of Dante puts further thought into this game: the thought was that with three dice, the lowest number you can get is three, an ace for every die. Achieving a four can be done with three dice by having a two on one die and aces on the other two dice.
Cardano also thought about the sum of three dice. At face value there are the same number of combinations that sum to 9 as those that sum to 10. For a 9:(621) (531) (522) (441) (432) (333) and for 10: (631) (622) (541) (532) (442) (433). However, there are more ways of obtaining some of these combinations than others. For example, if we consider the order of results there are six ways to obtain (621): (1,2,6), (1,6,2), (2,1,6), (2,6,1), (6,1,2), (6,2,1), but there is only one way to obtain (333), where the first, second and third dice all roll 3. There are a total of 27 permutations that sum to 10 but only 25 that sum to 9. From this, Cardano found that the probability of throwing a 9 is less than that of throwing a 10. He also demonstrated the efficacy of defining
odds
In probability theory, odds provide a measure of the probability of a particular outcome. Odds are commonly used in gambling and statistics. For example for an event that is 40% probable, one could say that the odds are or
When gambling, o ...
as the ratio of favourable to unfavourable outcomes (which implies that the probability of an event is given by the ratio of favourable outcomes to the total number of possible outcomes).
Seventeenth century
In addition,
Galileo
Galileo di Vincenzo Bonaiuti de' Galilei (15 February 1564 – 8 January 1642), commonly referred to as Galileo Galilei ( , , ) or mononymously as Galileo, was an Italian astronomer, physicist and engineer, sometimes described as a poly ...
wrote about die-throwing sometime between 1613 and 1623. Unknowingly considering what is essentially the same problem as Cardano's, Galileo had said that certain numbers have the ability to be thrown because there are more ways to create that number.
The date which historians cite as the beginning of the development of modern
probability theory
Probability theory or probability calculus is the branch of mathematics concerned with probability. Although there are several different probability interpretations, probability theory treats the concept in a rigorous mathematical manner by expre ...
is 1654, when two of the most well-known mathematicians of the time, Blaise Pascal and Pierre de Fermat, began a correspondence discussing the subject. The two initiated the communication because earlier that year, a gambler from
Paris
Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...
named
Antoine Gombaud had sent Pascal and other mathematicians several questions on the practical applications of some of these theories; in particular he posed the
problem of points
The problem of points, also called the problem of division of the stakes, is a classical problem in probability theory. One of the famous problems that motivated the beginnings of modern probability theory in the 17th century, it led Blaise Pascal ...
, concerning a theoretical two-player game in which a prize must be divided between the players due to external circumstances halting the game. The fruits of Pascal and Fermat's correspondence interested other mathematicians, including
Christiaan Huygens
Christiaan Huygens, Halen, Lord of Zeelhem, ( , ; ; also spelled Huyghens; ; 14 April 1629 – 8 July 1695) was a Dutch mathematician, physicist, engineer, astronomer, and inventor who is regarded as a key figure in the Scientific Revolution ...
, whose ''De ratiociniis in aleae ludo'' (Calculations in Games of Chance) appeared in 1657 as the final chapter of Van Schooten's ''Exercitationes Matematicae''. In 1665 Pascal posthumously published his results on the eponymous
Pascal's triangle
In mathematics, Pascal's triangle is an infinite triangular array of the binomial coefficients which play a crucial role in probability theory, combinatorics, and algebra. In much of the Western world, it is named after the French mathematician Bla ...
, an important combinatorial concept. He referred to the triangle in his work ''Traité du triangle arithmétique'' (Traits of the Arithmetic Triangle) as the "arithmetic triangle".
In 1662, the book ''
La Logique ou l’Art de Penser'' was published anonymously in Paris. The authors presumably were
Antoine Arnauld
Antoine Arnauld (; 6 February 16128 August 1694) was a French Catholic theologian, priest, philosopher and mathematician. He was one of the leading intellectuals of the Jansenist group of Port-Royal and had a very thorough knowledge of patr ...
and
Pierre Nicole
Pierre Nicole (; 19 October 1625 – 16 November 1695) was a French writer and one of the most distinguished of the French Jansenists.
Life
Born in Chartres in 1625, Nicole was the son of a provincial barrister, who took in charge his education ...
, two leading
Jansenists, who worked together with Blaise Pascal. The Latin title of this book is ''Ars cogitandi'', which was a successful book on logic of the time. The ''Ars cogitandi'' consists of four books, with the fourth one dealing with decision-making under uncertainty by considering the analogy to gambling and introducing explicitly the concept of a quantified probability.
In the field of statistics and applied probability,
John Graunt
John Graunt (24 April 1620 – 18 April 1674) has been regarded as the founder of demography. Graunt was one of the first demographers, and perhaps the first epidemiologist, though by profession he was a haberdasher. He was bankrupted later in ...
published ''Natural and Political Observations Made upon the Bills of Mortality'' also in 1662, initiating the discipline of
demography
Demography () is the statistical study of human populations: their size, composition (e.g., ethnic group, age), and how they change through the interplay of fertility (births), mortality (deaths), and migration.
Demographic analysis examine ...
. This work, among other things, gave a statistical estimate of the population of London, produced the first life table, gave probabilities of survival of different age groups, examined the different causes of death, noting that the annual rate of suicide and accident is constant, and commented on the level and stability of sex ratio. The usefulness and interpretation of Graunt's tables were discussed in a series of correspondences by brothers Ludwig and Christiaan Huygens in 1667, where they realized the difference between mean and median estimates and Christian even interpolated Graunt's life table by a smooth curve, creating the first continuous probability distribution; but their correspondences were not published. Later,
Johan de Witt
Johan de Witt (24 September 1625 – 20 August 1672) was a Dutch statesman and mathematician who was a major political figure during the First Stadtholderless Period, when flourishing global trade in a period of rapid European colonial exp ...
, the then prime minister of the Dutch Republic, published similar material in his 1671 work ''Waerdye van Lyf-Renten'' (A Treatise on Life Annuities), which used statistical concepts to determine
life expectancy
Human life expectancy is a statistical measure of the estimate of the average remaining years of life at a given age. The most commonly used measure is ''life expectancy at birth'' (LEB, or in demographic notation ''e''0, where '' ...
for practical political purposes; a demonstration of the fact that this sampling branch of mathematics had significant pragmatic applications.
De Witt's work was not widely distributed beyond the Dutch Republic, perhaps due to his fall from power and execution by mob in 1672. Apart from the practical contributions of these two work, they also exposed a fundamental idea that probability can be assigned to events that do not have inherent physical symmetry, such as the chances of dying at certain age, unlike say the rolling of a dice or flipping of a coin, simply by counting the frequency of occurrence. Thus, probability could be more than mere combinatorics.
Eighteenth century
Jacob Bernoulli
Jacob Bernoulli (also known as James in English or Jacques in French; – 16 August 1705) was a Swiss mathematician. He sided with Gottfried Wilhelm Leibniz during the Leibniz–Newton calculus controversy and was an early proponent of Leibniz ...
's ''
Ars Conjectandi
(Latin for "The Art of Conjecturing") is a book on combinatorics and mathematical probability written by Jacob Bernoulli and published in 1713, eight years after his death, by his nephew, Nicolaus I Bernoulli. The seminal work consolidated, ap ...
'' (posthumous, 1713) and
Abraham De Moivre
Abraham de Moivre FRS (; 26 May 166727 November 1754) was a French mathematician known for de Moivre's formula, a formula that links complex numbers and trigonometry, and for his work on the normal distribution and probability theory.
He move ...
's ''
The Doctrine of Chances'' (1718) put probability on a sound mathematical footing, showing how to calculate a wide range of complex probabilities. Bernoulli proved a version of the fundamental
law of large numbers
In probability theory, the law of large numbers is a mathematical law that states that the average of the results obtained from a large number of independent random samples converges to the true value, if it exists. More formally, the law o ...
, which states that in a large number of trials, the average of the outcomes is likely to be very close to the expected value - for example, in 1000 throws of a fair coin, it is likely that there are close to 500 heads (and the larger the number of throws, the closer to half-and-half the proportion is likely to be).
Nineteenth century
The power of probabilistic methods in dealing with uncertainty was shown by
Gauss
Johann Carl Friedrich Gauss (; ; ; 30 April 177723 February 1855) was a German mathematician, astronomer, Geodesy, geodesist, and physicist, who contributed to many fields in mathematics and science. He was director of the Göttingen Observat ...
's determination of the orbit of
Ceres from a few observations. The
theory of errors
In statistics, propagation of uncertainty (or propagation of error) is the effect of variables' uncertainties (or errors, more specifically random errors) on the uncertainty of a function based on them. When the variables are the values of ex ...
used the
method of least squares
The method of least squares is a mathematical optimization technique that aims to determine the best fit function by minimizing the sum of the squares of the differences between the observed values and the predicted values of the model. The me ...
to correct error-prone observations, especially in astronomy, based on the assumption of a
normal distribution
In probability theory and statistics, a normal distribution or Gaussian distribution is a type of continuous probability distribution for a real-valued random variable. The general form of its probability density function is
f(x) = \frac ...
of errors to determine the most likely true value. In 1812,
Laplace
Pierre-Simon, Marquis de Laplace (; ; 23 March 1749 – 5 March 1827) was a French polymath, a scholar whose work has been instrumental in the fields of physics, astronomy, mathematics, engineering, statistics, and philosophy. He summariz ...
issued his in which he consolidated and laid down many fundamental results in probability and statistics such as the
moment-generating function
In probability theory and statistics, the moment-generating function of a real-valued random variable is an alternative specification of its probability distribution. Thus, it provides the basis of an alternative route to analytical results compare ...
, method of least squares,
inductive probability
Inductive probability attempts to give the probability of future events based on past events. It is the basis for inductive reasoning
Inductive reasoning refers to a variety of method of reasoning, methods of reasoning in which the conclusion o ...
, and hypothesis testing.
Towards the end of the nineteenth century, a major success of explanation in terms of probabilities was the
statistical mechanics
In physics, statistical mechanics is a mathematical framework that applies statistical methods and probability theory to large assemblies of microscopic entities. Sometimes called statistical physics or statistical thermodynamics, its applicati ...
of
Ludwig Boltzmann
Ludwig Eduard Boltzmann ( ; ; 20 February 1844 – 5 September 1906) was an Austrian mathematician and Theoretical physics, theoretical physicist. His greatest achievements were the development of statistical mechanics and the statistical ex ...
and
J. Willard Gibbs which explained properties of gases such as temperature in terms of the random motions of large numbers of particles.
The field of the history of probability itself was established by
Isaac Todhunter
Isaac Todhunter FRS (23 November 1820 – 1 March 1884), was an English mathematician who is best known today for the books he wrote on mathematics and its history.
Life and work
The son of George Todhunter, a Nonconformist minister, ...
's monumental ''A History of the Mathematical Theory of Probability from the Time of Pascal to that of Laplace'' (1865).
Twentieth century
Probability and statistics became closely connected through the work on
hypothesis testing
A statistical hypothesis test is a method of statistical inference used to decide whether the data provide sufficient evidence to reject a particular hypothesis. A statistical hypothesis test typically involves a calculation of a test statistic. T ...
of
R. A. Fisher
Sir Ronald Aylmer Fisher (17 February 1890 – 29 July 1962) was a British polymath who was active as a mathematician, statistician, biologist, geneticist, and academic. For his work in statistics, he has been described as "a genius who ...
and
Jerzy Neyman
Jerzy Spława-Neyman (April 16, 1894 – August 5, 1981; ) was a Polish mathematician and statistician who first introduced the modern concept of a confidence interval into statistical hypothesis testing and, with Egon Pearson, revised Ronald Fis ...
, which is now widely applied in biological and psychological experiments and in
clinical trials
Clinical trials are prospective biomedical or behavioral research studies on human subject research, human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel v ...
of drugs, as well as in
economics
Economics () is a behavioral science that studies the Production (economics), production, distribution (economics), distribution, and Consumption (economics), consumption of goods and services.
Economics focuses on the behaviour and interac ...
and elsewhere. A hypothesis, for example that a drug is usually effective, gives rise to a
probability distribution
In probability theory and statistics, a probability distribution is a Function (mathematics), function that gives the probabilities of occurrence of possible events for an Experiment (probability theory), experiment. It is a mathematical descri ...
that would be observed if the hypothesis is true. If observations approximately agree with the hypothesis, it is confirmed, if not, the hypothesis is rejected.
The theory of stochastic processes broadened into such areas as
Markov process
In probability theory and statistics, a Markov chain or Markov process is a stochastic process describing a sequence of possible events in which the probability of each event depends only on the state attained in the previous event. Informally, ...
es and
Brownian motion
Brownian motion is the random motion of particles suspended in a medium (a liquid or a gas). The traditional mathematical formulation of Brownian motion is that of the Wiener process, which is often called Brownian motion, even in mathematical ...
, the random movement of tiny particles suspended in a fluid. That provided a model for the study of random fluctuations in stock markets, leading to the use of sophisticated probability models in
mathematical finance
Mathematical finance, also known as quantitative finance and financial mathematics, is a field of applied mathematics, concerned with mathematical modeling in the financial field.
In general, there exist two separate branches of finance that req ...
, including such successes as the widely used
Black–Scholes formula for the
valuation of options
In finance, a price (premium) is paid or received for purchasing or selling options.
The calculation of this premium will require sophisticated mathematics.
Premium components
This price can be split into two components: intrinsic value, and ...
.
The twentieth century also saw long-running disputes on the
interpretations of probability
The word "probability" has been used in a variety of ways since it was first applied to the mathematical study of games of chance. Does probability measure the real, physical, tendency of something to occur, or is it a measure of how strongly on ...
. In the mid-century
frequentism
Frequentist probability or frequentism is an interpretation of probability; it defines an event's probability (the ''long-run probability'') as the limit of its relative frequency in infinitely many trials.
Probabilities can be found (in pr ...
was dominant, holding that probability means long-run relative frequency in a large number of trials. At the end of the century there was some revival of the
Bayesian view, according to which the fundamental notion of probability is how well a proposition is supported by the evidence for it.
The mathematical treatment of probabilities, especially when there are infinitely many possible outcomes, was facilitated by
Kolmogorov's axioms
The standard probability axioms are the foundations of probability theory introduced by Russian mathematician Andrey Kolmogorov in 1933. These axioms remain central and have direct contributions to mathematics, the physical sciences, and real-worl ...
(1933).
References
Sources
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
External links
JEHPS: Recent publications in the history of probability and statistics*
ttps://www.economics.soton.ac.uk/staff/aldrich/Figures.htm Figures from the History of Probability and Statistics (Univ. of Southampton)Probability and Statistics on the Earliest Uses Pages (Univ. of Southampton)o
{{DEFAULTSORT:History Of Probability
*
Probability
Probability is a branch of mathematics and statistics concerning events and numerical descriptions of how likely they are to occur. The probability of an event is a number between 0 and 1; the larger the probability, the more likely an e ...