Maria Gaetana Agnesi, mathematician under faith

2013/07/01 Etxebeste Aduriz, Egoitz - Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Historia
• Biografiak
• Matematika

Milan, May 16, 1739. In a large hall, about thirty people from all European countries, in a circle, around the armchair. Two young sisters in the chair. All were attentive to the oldest. "I would have a score of years, neither ugly nor beautiful, little behavior and sweet," the French scholar De Brosses wrote. "The Count of Bellon threw the lady a good retolica in Latin... He responded with speed and skill in the same language. Subsequently, in the same language, the origin of the sources and the causes of the floods and decreases similar to the marine tides observed in some sources were discussed. He spoke like an angel, he had never heard anything so pleasant."

A D. Pietro Agnesi Mariami liked to organize such meetings in his house to show the talent of his daughters. Among the intellectuals and scholars of the area were held shortly the prestigious essays, which were often going to listen to Pietro's eldest daughter on matters of physiosophy, science and mathematics. In fact, Maria Gaetana was able to talk about many things and in several languages. In the pauses, little sister María Teresa played the harp.

"Count Belloni wanted me to speak with my lady of any subject of mathematics or natural philosophy that I had chosen; and we talked about the expansion of the light and colors of the prism," continues De Brossese. "He spoke of Newton's philosophy; it is wonderful for a person of that age to hear about these abstract subjects. Loppin then spoke to him about transparent bodies and geometric curves, and in the latter I understood nothing. Then the dialogue became generalized; each one spoke in his language and he answered in the same language. It has a wonderful knowledge of languages. Then he told me that he felt that the visit seemed to him the defense of a thesis and that he did not like to speak in public about this type of subject, because twenty are bored for every person who has fun."

Agnes was, in fact, silent and shy, and did not like those events. He did so with respect for the father. His father was a wealthy businessman who wanted to give his children the best training, bringing home the best teachers they could. Mary Gaetana showed from the beginning that she had extraordinary endowments, especially for languages and mathematics. At the age of thirteen he dominated Latin, Greek, Hebrew, French, Spanish and German.

"I was very sorry when he told me that I wanted to enter a convent," De Brossese-wrote, "and it was not for necessity, because I was rich." That was Agnesi's desire. But soon after his mother died, in the eighth childbirth, and then he reached an agreement with his father, who would stay in the house taking care of his father and his brothers with three conditions: he would go to Mass as many times as we wanted, dress humble and did not have to participate in parties and dances.

From that moment on, in addition to fully leaving social activities and taking care of his 20 brothers (the father would marry twice more), he devoted himself to religion and mathematics. The result of the mathematical work carried out in the next ten years was the Italian Institute analytic ad uso della gioventú, composed of two volumes. It was a complete textbook of calculus, from algebra to differential equations. Thanks to a lot of perfectly chosen examples and illustrations, he explained very clearly the concepts and collected the works of many mathematicians who until then were distributed in a logical and didactic evolution.

It began as a pastime, continued as a book of studies for his brothers and ended up being an important publication. He published it in 1748, printed at home with his father's money. Dedicated to Mary Teresa of Austria (under her authority Milan): "If one can ever dislike the temerity of a woman for daring to pursue the exaltation of a science without limits, it should be in this age, in which a woman recites... At this time, every woman should strive and strive to foster the glory of her sex."

Pope Benedict XIV wrote to him saying that he learned mathematics as a young man and that, therefore, he could verify that this work brought prestige to the country and the Academy of Bologna. He gave him a gold medal and a stone crown and offered him the Chair of the University of Bologna: "Bologna has already had people of the same sex in public positions. We believe it fitting to follow this honored tradition."

Agnesi seems not to take into account this invitation. By then, he had almost total retirement, and although for 45 years his name was on university lists, he never appeared in Bologna. In fact, from the death of his father in 1752, at 34 years old, he completely abandoned mathematics and had as sole aim charity. From then on he would spend his whole life helping the poor and caring for the sick, especially for old and sick women.

Meanwhile, the fame of Agnesi's book would spread throughout Europe. A report from the Paris Academy of Sciences said it was "the most complete and best written work of its kind." And the secretary of the academy writes to Agnesi: "Let me add my personal tribute to the applause of the entire Academy. I do not know another work as clear, complete and methodical as this one. There is nothing other than in other languages, that people who want to advance in mathematics lead them in such a safe and fast way, and carry them forward. I especially admire the art with which you have gathered, the uniform methods, the consequences of the geometries with different methods". The Agnesi Institute was translated into several languages and the textbook would be used for at least 50 years in many European countries.

Agnesi spent all his money on charity until he remained almost without anything. In 1771 Archbishop Tozzobonelli was appointed director of the Trivulzio protection centre in Milan. He died in January 1799.