816 
whole value of philosophy for him lay in the light it 
shed on moral problems, and on the power it gave man 
to interpret the Christian revelation. His point of view, 
while it accepts the principles of Descartes’s philosophy, 
applies them in a way which makes his doctrine its 
very antithesis. 
Descartes was shown the Treatise on Conic Sections 
which Pascal composed when sixteen, and refused to 
believe in its originality. He thought it the work of 
Desargues, from whom indeed Pascal had learnt much, 
but Desargues himself acknowledged the originality 
of Pascal’s treatise in its essential points. In 1647 
Descartes paid two visits to Pascal, who had come to 
Paris with his sister Jacqueline for medical advice. 
Jacqueline has given an account of their meeting in a 
letter to her sister Gilberte Périer. They discussed the 
question of the void. Torricelli, the pupil of Galileo, 
had demonstrated the phenomenon of atmospheric 
pressure by the famous invention of the barometer, 
inverting a column of mercury in a glass tube closed at 
one end, with the other end immersed in an open 
mercury bath, and then measuring the height of the 
column. 
This was of course the crucial experiment, but 
there still remained considerable doubt as to its inter- 
pretation. To many, including Torricelli himself, it 
was merely a case in point of the old principle that 
nature abhors a vacuum. Descartes had rejected this 
principle on a priori grounds. Pascal explained to 
Descartes his theory of an ocean of air, at the bottom 
of which we were situated, and assumed that like all 
fluids it would maintain an equilibrium, and reasoned 
that above every point of the earth’s surface was a 
column pressing down on us, the weight of which would 
vary with the altitude. He had already made experi- 
ments to prove this on a tower in Rouen, and he now 
proposed to carry out an experiment on a large scale 
on the Puy de Dome in Auvergne. Descartes dis- 
cussed it with great interest and confidently foretold 
its success. The experiment was carried out by the 
aid of Pascal’s brother-in-law, M. Périer, with the 
result that the time-honoured, firmly established 
principle of the abhorrence of a vacuum passed 
into limbo, 
Pascal’s life divides naturally into three periods. 
To the first belong the mathematical works and the 
physical experiments, to the second the literary 
achievement of the “ Lettres Provinciales,’”’ and to the 
third the philosophical and mystical “ Pensées.” In 
all of them his great genius is manifest, and he might 
easily have been one of those master minds which 
determine the direction of human thought. In science 
and philosophy he showed an intellectual power and 
incentive which places him on a level with Descartes 
and Galileo, yet he stands alone, grand but solitary, in 
the great intellectual movement of humanity. It was 
more than a religious act, it was typical of his whole 
intellectual position, when he joined the solitaires of 
Port Royal. We may count his unworldliness as loss 
or as gain, but he sacrificed for it alike scientific and 
philosophic leadership. The tragedy is that the Chris- 
tian Church did not value what he gave to her when 
he renounced the world. 
The works by which Pascal has immortalised himself 
NO. 2798, VOL. 111 | 
NATURE 

[JUNE 16, 1923 
are “ Les Lettres Provinciales” and “‘ Les Pensées.” - 
His mathematical works, like his arithmetical machine _ 
which took three years to perfect and is preserved at 
the Conservatoire des Arts et Métiers in Paris, are 
valuable for the evidence they afford of the nature of 
his genius rather than for their originality of discovery, 
but the two great literary works have been read in 
innumerable successive editions. Yet strangely enough 
both are valued and cherished for what to Pascal him- 
self was purely adventitious and no part of the original 
design. The ‘“‘ Provinciales ” are classical on account 
of their attack on the Jesuits and for the exposure of 
Jesuit casuistry. The world has little interest to-day 
in the Jansenist doctrine, which it was the main pur- 
pose of the letters to expound and to defend. Were it 
not for Pascal, the very names of Jansenius and Molina 
would scarcely be known outside narrow theological 
circles. The doctrine of sufficient grace has little more 
than antiquarian interest for students, but for Pascal 
it was the rationalising of Christian doctrine, the philo- 
sophy of a religion of redemption as distinct from the 
institution of sacraments and formularies founded on it. 
The “Lettres Provinciales” had an immediate 
success, but it is unlikely that they would have accom- 
plished their design, or have afforded even a temporary 
cessation of the Jesuit hostility against the theologians 
of Port Royal, but for an event of an altogether different 
nature, and one which had a powerful influence on 
Pascal himself. This is what is known as the miracle 
of the sacred thorn. Pascal’s niece, Marguérite Périer, 
was a pensionnaire at Port Royal, and the little girl 
suffered from an abscess of the lachrymal gland, which 
discharged into the eye and into the nose, causing her 
inconvenience and suffering. Medical treatment had — 
proved wholly ineffective, but after having touched the 
spot one day with the relic of the sacred thorn, exposed 
for adoration on the altar, she was completely cured. — 
The doctors certified that “la guérison surpassait les” 
forces ordinaires de la nature,’ and the miracle was 
solemnly attested by the vicars-general of the Arch- 
bishopric of Paris. 
“Les Pensées”” was not designed by Pascal for 
publication in any form whatever. When he died a 
disordered mass of papers containing his written notes — 
was found. They were unconnected, casual, jottings 
on odd bits of paper, many being incompleted sen- 
tences. It was known that Pascal had had in mind to 
write an “ Apology ” of Christianity, a defence against 
atheistical arguments. The editors took this as the 
clue to the arrangement of the fragments, and Arnauld, 
Nicole, and other leaders of Port Royal, after the 
“peace of the church,” which restored them to their 
monastery in 1669, published the first edition of the 
“ Pensées.”” Few books have had such a success. 
Edition has followed edition through the succeeding 
centuries. The original fragmentary notes still exist, 
and scholars may now study them in the “ Repro- 
duction en phototypie du manuscrit des Pensées 
de Blaise Pascal,” published by Monsieur Léon 
Brunschvicg. 
Such was the marvellous genius, the tercentenary of 
whose birth is being celebrated this year in his native 
city, Clermont, and at the scene of his activities, Port 
Royal des Champs, near Paris. 

