WITCH OF AGNESI: THE TRUE STORY

Abstract The recent celebration of the three hundredth anniversary of the birth of Maria Gaetana Agnesi, offers an opportunity to reflect on how we have understood and misunderstood her legacy to the history of mathematics. Maria Gaetana was the author of an important vernacular textbook, Instituzioni analitiche ad uso della gioventú italiana (Milan, 1748), the first book dedicat-ed to learners of mathematics and one of the best-known women natural phi-losophers and mathematicians of her generation. Most popularly and erroneously, Agnesi is known as the woman who discovered a cubic curve that the English mathematician John Colson, while occupying the Lucasian professorship of Mathematics, called “the witch”, leading to its mod-ern description as “the witch of Agnesi”. Colson inflicted dual infamy to Agnesi, crediting her with a result that belonged to the preceding generations of mathe-maticians, while damning her for the ages by presenting her no discovery as a product of diabolic female power. This article is dedicated to restoring the truth and giving Agnesi the right place it deserves in the history of mathematics and its teaching.