Eleven days in the life of Pascal: June 1635, bushy geometry

This article is taken from the

Figaro Hors-Série Blaise Pascal, the heart and the reason.

How much longer will he be able to evade his son's questions?

To hide from feverish eyes, which question the slightest of his gestures when he engages in geometric projections and constructions of tangents?

Second president in the Court of Aids of Montferrand, Étienne Pascal belongs to the world of magistrates and finance people who hold studies in high esteem, Greek and Latin, philosophy, history, canon and civil law, theology and math.

A follower of experience as a scientific compass, he is respected by those who, like him, seek to understand nature and to account for this mysterious order that they see there.

The highest scholars seek his advice, Father Marin Mersenne, who brings together in his academy the greatest mathematicians and geometers of the time, even dedicated to Étienne, whose musical compositions he esteems, his treatise On Organs.

It is moreover to enjoy the company of people of his quality, just as much as to flee the plague which decimated Clermont, that

Read alsoThe editorial of Le Figaro Hors-série: Blaise Pascal, a man for eternity

Since childhood, her son never ceases to amaze her.

At home, Étienne detects an immeasurable thirst for understanding.

This frail boy, whose health very quickly concerned him, seems to have learned to reason at the same time as to speak.

The winds, the snow, the rain, the gunpowder, the sounds, he wants to grasp the causes, the mechanisms, and shows himself very unhappy when he is given too light a discourse.

All of life is for him discovery and food for thought.

After hearing the echo of a knife hitting an earthenware dish, the child engages in all sorts of sound experiments and composes a treatise on sounds.

He is only eleven years old, and urges his father to teach him the science to which he sees him devoting himself.

Geometry, Étienne replies, is the way to make correct figures and to find the true proportion they have between them.

Let it be taught to him, begs Blaise!

President Pascal certainly has no intention of leaving his son in the dark.

But he wants him to first learn languages, grammar, before allowing Blaise to approach mathematics, of which he knows only too well the bewitching charm.

His father may have forbidden him to think about it, the child devotes himself, all alone, to bushy geometry.

In his spare time, Blaise draws shapes with charcoal that he strives to make perfect.

With his child's words, he calls the circle a round, the line a bar, and tries to calculate the proportions of these figures between them.

Absorbed by this work, one morning in June 1635, the child did not hear his father enter the room where he was contemplating the triangles he had just drawn on the tiles of the new house they lived in rue Brisemiche, not far from of Saint Merri.

Stunned, Étienne questions him.

Surprised in these forbidden games, Blaise nevertheless explains that he believes he understands that the sum of the interior angles of a triangle is equal to two right angles.

Stephen questions further, and finds that his son has just found by himself, without any instruction, the thirty-second proposition of Euclid, and the essential of those which come before.

"

»

Jacques Le Pailleur is one of those joyful libertines who cherishes music, song, dance, burlesque poetry as well as mathematics.

Seeing Étienne Pascal enter his house in tears, Le Pailleur is moved and asks him to tell him the cause of his displeasure.

“

»

The child has genius, we can't restrain him any longer: Euclid will be his recreation reading.

From now on, Pascal father will take his son to his scholarly circles.

It was there that, at the age of sixteen, Blaise presented his Traite des coniques.

Everyone applauds.

Descartes alone still disdains the young prodigy.

Blaise Pascal, heart and reason

Cover after the posthumous portrait of Blaise Pascal by François II Quesnel, after 1662 Figaro-Hors-Série