Maria Agnesi

1718 - 1799

by

Susan Lagore

Gulf Coast Community College
April 2000

 

Maria Gaetana Agnesi was born to wealth in Milan, Italy, but died in poverty as she devoted the last years of her life to helping others. While Maria is best remembered for her contributions to mathematics, she was not a typical mathematician. The shy woman, who never married, appeared to study mathematics in an effort to please her father. But after her father's death, she retired from the spotlight she never wanted and gave up her work in mathematics.

Maria was born in Milan, Italy, on May 16, 1718, to a wealthy and literate family. She was the daughter of Pietro Agnesi, who came from a wealthy family who made its money from silk. Maria was the oldest of 21 children her father had with his three wives.

There have been conflicting reports about whether or not Maria’s father was a professor of mathematics at the University of Bologna. While scholars have disagreed about Pietro's career, one thing is certain: Pietro took a keen interest in the education of his eldest child, Maria. It's certain that Pietro hired the best available tutors to instruct Maria, but there has been some debate as to whether the tutor was a professor from the University of Bologna or whether the tutor was an educated man from the Church.

Maria took quickly to her lessons and was considered a child prodigy. She spoke French by the age of five and also learned Latin, Greek, Hebrew, German and Spanish. She was known as the "oracle of the seven tongues."  But it was while she was a teen-ager that Maria mastered mathematics.

While Maria was growing up, Pietro Agnesi invited notable intellectuals of that time to his home for spirited discussions on philosophy and other scholarly subjects. Although Maria was shy by nature, she participated in these gatherings and impressed her elders with her knowledge and insight.

C. de Brosses wrote about an evening he spent with the Agnesis on July 16, 1739, in the book Lettres Historique et Critiques sur l'Italie. He wrote:

I was brought into a large fine room, where I found about thirty people from all countries of Europe, arranged in a circle and Mlle Agnesi, all alone with her little sister, seated on a sofa. She is a girl of about twenty years of age, neither ugly nor pretty, with a very simple and very sweet manner. … Count Belloni, who took me, wanted to make a public show. He began with a fine discourse in Latin to this young girl, that it might be understood by all. She answered him well, after which they entered into a dispute, in the same language, on the origin of fountains and on the causes of the ebb and flow which is seen in some of them, similar to tides at sea. She spoke like an angel on this topic. I have never heard anything so pleasurable.

She continued her participation in these meetings to please her father, but after her mother died, Maria wanted to enter a convent. Her father, however, decided that Maria should be responsible for the education of her siblings. Maria "retired from public life" and became manager of the Agnesi household.

The following is another quote from de Brosses on this subject:

She told me that she was very sorry that the visit had taken the form of a thesis defense, and that she did not like to speak publicly of such things, where for every one that was amused, twenty were bored to death. … I was much annoyed to hear it said that she wished to enter a convent and it was not through need, for she is very rich.

Despite caring for her father and twenty siblings, Maria did not give up mathematics.

In 1738, she published Propositiones, Philosophicae, a collection of essays on natural science and philosophy. Among the subjects discussed were philosophy, logic, physics and Isaac Newton’s theory of universal gravitation. In the essays, which were based on the discussions held at her father’s home, Maria advocated strongly for the education of women.

Maria also began work on a calculus textbook to be used by her brothers. But what started out as a guide for her brothers ended up being Maria's most important works. This book, Analytical Institutions, was published in 1748. The book was one of the first and most complete works on finite and infinitesimal analysis. Maria, who was aided by her ability to speak several languages, brought together other mathematicians’ work in a very orderly manner and added her own interpretations. Her books were translated into English and French and were widely used as textbooks.

After the book was published, Pope Benedict XIV wrote to Maria saying he had studied math when he was young and could see her work would bring credit to Italy. Soon after this, he appointed Maria to the position of honorary reader at the University of Bologna.

Maria was then approached by the president of the Academy of Bologna and three other professors of the Academy and invited to accept the chair of mathematics at the University of Bologna. There has been some debate as to whether Maria accepted the position because her father was very ill at that time. According to some reports, Maria did accept the position and worked at the university until her father’s death in 1752. Many believe that Maria’s father was her inspiration in the mathematical field and after his death, she gave up any more work in the field.

After she gave up her position at the university, Maria devoted the rest of her life to helping the needy and less fortunate. The religious woman worked with the poor, the homeless, and the sick. Maria also was given an appointment to the Pio Instituto Trivulzo, a home for the sick. After spending all her money on this charitable work and all her time taking care of ill and dying women, Maria died at the age of 81 in total poverty.

Maria is best known for her work on the Witch of Agnesi. The solution for an algebraic equation follows a curve now called the Witch of Agnesi. The curve got this name because the shape of the curve was called aversiera, which means "to turn" in Italian. The word is also slang for avversiere, which means "wife of the devil." Over time, mistranslations set the name of the curve as the Witch of Agnesi.

Although Maria died more than 200 years ago, she has not been forgotten. On the hundredth anniversary of her death, Milan celebrated her memory and roads in three Italian cities bear her name.

 

References

Britannica: Maria Gaetana Agnesi

Britannica

MathNews: More Women in Math

Agnes State College

Biography Resource Center