Emilangues
Pascal ‘s BIOGRAPHY
BLAISE PASCAL FRENCH (1623-1662)
Blaise Pascal, (1623 – 1672).
Huile sur toile.17e siècle
(C) RMN – GP (Château de Versailles et de Trianon) / Droits réservés
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I.
Presentation
The person
a) Dates: birth and death.
June 19, 1623 – August 19, 1662.
b) Where does he come from?
He was born in Clermont-Ferrand, in the Auvergne region of France.
c) Did his family’s occupation show him the way?
Definitely.
Blaise Pascal lost his mother, Antoinette Begon, at the age of three. His father, Étienne Pascal (1588–
1651), was a local judge and member of the "noblesse de robe", who also had an interest in science and
mathematics.
In 1631, shortly after the death of his wife, Étienne Pascal moved with his children to Paris.
Étienne, who never remarried, decided that he alone would educate his children, for they all showed
extraordinary intellectual ability, particularly his son Blaise.
Young Pascal showed an amazing aptitude for mathematics and science. At the age of eleven, he
composed a short treatise on the sounds of vibrating bodies and Étienne responded by forbidding his son
to further pursue mathematics until the age of fifteen so as not to harm his study of Latin and Greek. One
day, however, Étienne found Blaise (now twelve) writing an independent proof that the sum of the angles
of a triangle is equal to two right angles with a piece of coal on a wall. From then on, the boy was allowed
to study Euclid’s work; perhaps more importantly, he was allowed to sit in as a silent on-looker at the
gatherings of some of the greatest mathematicians and scientists in Europe — such as Roberval,
Desargues, Mydorge, Gassendi, and Descartes — in the monastic cell of Père Mersenne.
d) Job, what age, where did he start?
At the age of eleven, he composed a short treatise on the sounds of vibrating bodies.
Sixteen-year-old Pascal produced, as a means of proof, a short treatise on what was called the “Mystic
Hexagram”, Essai pour les coniques (“Essay on Conics”).
The background
e) The century
Beginning of the 17th.
f) What happened in political life and society at that time? (Wars, dictatorship, Church…)
The Thirty Years' War was fought between 1618 and 1648, principally on the territory of today's
Germany, and involved most of the major European continental powers. Although it was ostensibly a
religious conflict between Protestants and Catholics, the rivalry between the Habsburg dynasty and other
powers was a more central motive.
Like so many others, Étienne was eventually forced to flee Paris because of his opposition to the fiscal
policies of Cardinal Richelieu.
Jansenism.
g) What happened in the scientific field at that time? (Main discoveries, state of
knowledge, contemporary people…)
Descartes 1596-1650
Galileo 1564 –1642
Huygens 1629-1695
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II.
His work
Works and discoveries
h) What is he famous for?
In honor of his scientific contributions, the name Pascal has been given to the SI unit of pressure, to a
programming language, and Pascal's law (an important principle of hydrostatics), and as mentioned
above, Pascal's triangle and Pascal's wager still bear his name.
- Mathematics:


1642: in an effort to ease his father's endless, exhausting calculations, and recalculations, of taxes
owed and paid, Pascal, not yet nineteen, constructed a mechanical calculator capable of addition
and subtraction, called Pascal's calculator or Pascaline. The Musée des Arts et Métiers in Paris
In 1653, Pascal wrote his Traité du triangle arithmétique ("Treatise on the Arithmetical Triangle")
in which he described a convenient tabular presentation for binomial coefficients, now called
Pascal's triangle.
- Contributions to the physical sciences:
By 1646, Pascal had learned of Evangelista Torricelli's experimentation with barometers. Having
replicated an experiment which involved placing a tube filled with mercury upside down in a bowl of
mercury, Pascal questioned what force kept some mercury in the tube and what filled the space above the
mercury in the tube. At the time, most scientists contended that, rather than a vacuum, some invisible
matter was present. This was based on the Aristotelian notion that creation was a thing of substance,
whether visible or invisible
On September 19, 1648, after many months of Pascal's friendly but insistent prodding, Florin Périer,
husband of Pascal's elder sister Gilberte, was finally to carry out the fact finding mission vital to Pascal's
theory. the Puy-de-Dôme.
Pascal replicated the experiment in Paris by carrying a barometer up to the top of the bell tower at the
church of Saint-Jacques-de-la-Boucherie, a height of about fifty meters. The mercury dropped two lines.
These, and other lesser experiments carried out by Pascal, were hailed throughout Europe as establishing
the principle and value of the barometer.
- Religion, philosophy, and literature:
Link with Jansenism, lettres provinciales, pensées
i) Which less famous work did he do?
- Mathematics:
In 1654, prompted by a friend interested in gambling problems, he corresponded with Fermat on the
subject, and from that collaboration was born the mathematical theory of probabilities.
- Theology:
Pascal later (in the Pensées) used a probabilistic argument, Pascal's Wager, to justify belief in God and a
virtuous life.
Pascal's major contribution to the philosophy of mathematics came with his De l'Esprit géométrique (“On
the Geometrical Spirit”),
- Contributions to physical sciences
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In 1647 Pascal produced Expériences nouvelles touchant le vide (“New Experiments with the Vacuum”),
which detailed basic rules describing to what degree various liquids could be supported by air pressure. It
also provided reasons why it was indeed a vacuum above the column of liquid in a barometer tube.
- Religion, philosophy, and literature:
 Ttwo basic influences led him to his conversion: sickness and Jansenism.
From as early as his eighteenth year, Pascal suffered from a nervous ailment that left him hardly a day
without pain. In 1647, a paralytic attack so disabled him that he could not move without crutches. His
head ached, his bowels burned, his legs and feet were continually cold,
 Blaise spoke with the doctors frequently, and upon his successful treatment of Étienne, borrowed
works by Jansenist authors from them. In this period, Pascal experienced a sort of “first
conversion” and began to write on theological subjects in the course of the following year.
Jacqueline, his sister, left for Port-Royal in 1651.
1654: conversion. Terrified by the nearness of death, for the next four years, he regularly travelled
between Port-Royal and Paris. It was at this point immediately after his conversion when he began
writing his first major literary work on religion, the Provincial Letters.
Unfortunately, Pascal's most influential theological work, referred to posthumously as the Pensées
(“Thoughts”), was not completed before his death.
j) What books did he write? (Title, date…)
-
Essai pour les coniques (1639)
Experiences nouvelles touchant le vide (1647)
Traité du triangle arithmétique (1653)
Lettres provinciales (1656–57)
De l'Esprit géométrique (1657 or 1658)
Écrit sur la signature du formulaire (1661)
Pensées (incomplete at death)
His work’s influence in the history of science
k) How was his work accepted? (Were people shocked? Was it criticized? Was it admired?
Was it published?)
Yes, but His insistence on the existence of the vacuum also led to conflict with a number of other
prominent scientists, including Descartes.
l) Who took up his ideas and went further?
Development of probability: Christiaan Huygens, learning of the subject from the correspondence of
Pascal and Fermat, wrote the first book on the subject. Later figures who continued the development of
the theory include Abraham de Moivre and Pierre-Simon de Laplace.
m) Has his work/has his work had technological or philosophical applications?
III. Your conclusion: for you, why can he be said an important
person?
Sources : http://en.wikipedia.org/wiki/Blaise_Pascal
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