Marie-Louise Dubreil-Jacotin

Extract from the Annuaire des Anciens Élèves de l'École Normale Supérieure (1974) by Jean Leray

[Note that a year in parenthesis after a person's name indicates their year of admission to the École Normale Supérieure].

DUBREIL (Mme PAUL, née Marie-Louise JACOTIN), born at Paris 7 July 1905, died at Paris 19 October 1972; admitted to the École Normal Supérieure in 1926.

Marie-Louise Jacotin was born with the qualities needed to become a mathematician. She had determination, intelligence and composure. To these personality traits she added what were then considered more feminine qualities. Her colleagues admired her deeply even if they felt shy about expressing their affection directly to her. She, however, sensed their support and felt that it helped her when she had serious difficulties.

She was a pioneer not by choice but by necessity. She needed boldness and daring to overcome the obstacles which the time in which she lived placed in her path. She was, however, changed neither by her ambition for an exceptional career nor by a passionate feminism. These were both aspects of her rich personality and the need to express herself in her own individual way.

It is true that two other women had become eminent mathematicians before her. Sonia Kovalevskaya, had overcome the Russian customs of the 19th Century, and Emmy Noether at Göttingen at the beginning of the 20th Century had succeeded in playing important and even prestigious roles in their mathematical research and higher learning. But they owed it to the support of two famous scholars: Weierstrass and Hilbert. Indeed, thanks to the liberalism of Ernest Lavisse, the scientific intake of 1910 had included Mme Rivière (née Rouvière) whose marriage diverted her from physics. This precedent allowed Mme Flamant (née Parize) who was a teacher at Fénelon to enter the École in 1917. However, since then our school remained inaccessible to young women, while the school at Sèvres and the agrégations feminines [competitive exams to allow women to teach in secondary schools] selected candidates by tests which were trite, lenient and superficial.

The mother of our classmate (née Rodon) came from a family of master glass-blowers of Briare originally from Greece. She had learnt singing, painting and ornamentation and for three years she managed Marie-Louise's studies leading to a remarkable intellectual blossoming at the cost of, perhaps, a certain neglect of addition, multiplication and spelling which, then, used to feed the intellectual curiosity of children. Marie-Louise's character, so firm and so polite, revealed itself to be even more precocious: even at four years old she declared to someone who offered her a titbit, "Aunt Amelie, when I say no, it is no".

In those days, very few girls went to secondary school. When the Jules-Ferry Lyceé opened, her father, whose training was in law, put Marie-Louise's name down. She was a brilliant pupil. The sister of Elie Cartan, who taught there, noticed her aptitude for mathematics. Her friendly spirit and her engaging manner full of vivacity explains the strong friendships she formed with fellow-pupils: two of whom, Denise Coulom and Simone Hauser were luckily able to help Marie-Louise to overcome the first obstacles to her ambition.

Few female secondary pupils tackled the baccalaureate in elementary mathematics. In 1922-23 the marvellous mathematics teacher Mme Uhlmann had only nine "little girls" in her class. This was how she referred to her elite pupils whose courage in undertaking scientific studies was related to their happy friendship. This "group of stars" admired the flair of Marie-Louise.

The École at Sèvres did not attract her: the studies were too far removed from real science. By good luck her friend Denise Coulom, who knew her worth, was the daughter of the head of the municipal college of Chaptal. M. Coulom had the intelligence, goodness and boldness to accept Marie-Louise into the special mathematics classes reserved for male students. She benefited from excellent teaching: in particular that of Georges Milhaud (1899). There she met a future classmate André Adler. Unfortunately, her father, head of the legal department of the land bank of France was dying slowly. This sad family drama, ending just before the entrance to the École, exhausted Marie-Louise physically. She only obtained a Bourse de licence [which would only have allowed her to study outside Paris] and she decided not to accept it.

In 1925-26, encouraged by her teacher Milhaud she performed at her best and came top of the preparatory class. She did this with great talent and in a friendly atmosphere. At the entrance examination of 1926 the jury ranked her second. The ranking was published with the official note: "The nomination of the students to the École Normal Supérieure will be by order of rank". But the decree of the ministry published afterwards in the official journal named twenty male students at the top and then Marie-Louise at the head of the Boursiers de licence. This decree had moved her down to 21st place.

She expressed her "sad disappointment" to the Minister of Public Instruction and Fine Arts, Edouard Herriot (1894). She asked to be allowed to attend the École Normale Superieur as an extra day pupil or, if that were not possible, to take courses at the school so as not to lose "the minimum benefit of her rank of admission."

Her friend Simone Hauser alerted her father to Marie-Louise's difficulties. Fernand Hauser was a member of staff of Journal from which readers learned of the events of October 10, 1926. He told the story to E. Herriot who showed surprise and sent it to Cavalier (1888), head of higher education. He had just taken up this post and was very clear. "I do not know who has done this. What is certain is that Mlle Jacotin was second in the examination and that she is a pupil of this school ... but she should be careful. She is going to create a precedent and traditions. On her will depend what we will be able to decide concerning future candidates."

In L'Oeuvre D. de la Fouchardière wrote a comic article and then on 12th October Jean Piot (1908) expressed himself in a lively way about G. Lanson (1876), director of the École Normale Supérieure, "... who has the enterprise to restore the old house in the Rue d'Ulm as a seminary ... and who fiercely tries to protect his female students from the attentions of the 20th Century". Then Jean Piot humorously reassured the minister who believed that Mlle Jacotin "would have the traditional initiations and would stay quite innocent". Later, the serious Journal des débats declared on 13th October that "It is time to reconsider justice and sense".

The Third Republic demanded that the administration justify its decision. The Press, the complaints from the Senate and the Chamber were dreaded by the Ministries. On October 22, 1926 E. Herriot transformed Marie-Louise's Bourse de licence which would have only enabled her to study in the provinces into a Bourse près de L'Universite de Paris. When the academic year began again Marie-Louise Jacotin started her higher education but she did not officially matriculate until the following February 1927. Of course her presence was a pretext for practical jokes, but they were all harmless. At this time anyone staying out past ten in the evening had to sign a register when they came in. They all signed "Marie-Louise Jacotin" and the rule was discontinued.

An old house in the Rue d'Ulm was refurbished for the use of female students. Thirty-four came after Marie-Louise of whom three became professors in provincial universities, four in Paris and one at the Collège de France. Their example proved that male and female students could study together in Paris. The time came when those women cloistered in the suburbs at Sèvres could study at the Sorbonne.

Along with C. I. Chevalley, who did not take long to acquire international scientific fame, Marie-Louise Jacotin graduated brilliantly in 1929. E. Vessoit immediately arranged a doctoral scholarship for her. She had already studied at the Collège de France. She and some of her classmates had taken a course with Lebesque ([admitted to the École Normal in] 1894), seminars with Hadamard (1884) and she was attracted by the teaching of Villat (1899) on fluid mechanics at the Sorbonne. On his advice she accepted an invitation from Bjerknes at Oslo. He was a Norwegian scholar of great originality who as a physicist had studied and made discoveries about the atmosphere. He was interested in the fronts separating cold and warm areas of the atmosphere, their obliqueness and their oscillations which give rise to atmospheric disturbances, cyclones included. Bjerknes planned a treatise which Marie-Louise Jacotin would translate into French. Under the influence of the Norwegian school she became interested in the mathematical theory of waves in ideal liquids, in particular in the work of Levi-Civita.

On her return to Paris she married Paul Dubreil (1923) on June 28, 1930. He had been a lecturer at the École Normal Supérieure. While she was a student who had devoted her years there only to study. She went with her husband to Frankfurt where she met Emmy Noether. She wrote some moving pages about Noether in her article Portraits of women mathematicians (this is included in the collection Important Trends in Mathematical Thought (Les grands courants de la pensée mathématique), edited by F. Le Lionnais). Marie-Louise Dubreil claimed E. Noether to be a model of high scientific ideals, intellectual integrity, devotion, and kindness. She contributed so much to the rise of modern algebra.

Paul and Marie-Louise spent the winter term of 1930-31 in Rome. At her first meeting with the renowned Levi-Civita, she told him about an important difference between the irrotational wave he had just described (of an ideal liquid with a free surface) and a rotational wave which Gerstner had described a long time before (the cycloidal wave). This provokes a movement of mass in deep layers. Levi-Civita, surprised and interested, encouraged her to continue her studies. She established the existence of an infinity of waves, those of Gerstner and Levi-Civita being two examples. This would be her thesis. Its importance and that of her work on the theory of waves meant that she extended work on it until 1935. These ideas would be better appreciated by hydraulic engineers and meteorologists (cf. Chia-Shun Yih, Journal of Fluid Mechanics, (1967) 23 539).

For the summer term Paul and Marie-Louise were at Göttingen with a group of brilliant mathematicians the most eminent of whom were David Hilbert and Hermann Weyl. Less than two years later they would have the terrible shock of being dispersed by Nazism. Paul and Marie-Louise joined in taking a broad interest in everything. Paul found Emmy Noether again and Marie-Louise took up her collaboration with Bjerknes which delayed the presentation of her thesis.

The appointment of Paul to Lille took them back to France. Marie-Louise defended her thesis in 1934. Under the influence of all the algebraists that she had known at the Séminaire Julia she chose algebra as her second subject. The jury was presided over by Ernest Vessiot (1884). The other members were Gaston Julia (1911) and Henri Villat (1899). Jacques Hadamard (1884) came to help with the defence and to sit at her side.

Their daughter Edith was born on the 22nd of September 1936.

They were now at Nancy, but the Science Faculty where Paul was working hesitated to recognise the scientific worth of Marie-Louise. They were afraid to nominate the wife of a colleague. She went to work at Rennes from 1939 to 1940 and from there to Lyon and then back to Rennes. From October 1943 she had a permanent appointment at Poitiers. Their child Edith was raised in Paris. Her parents took it in turns week and week about to be with her.

The defeat, the occupation and the liberation made these never-ending trips to and from Paris slower and more difficult and dangerous. The train that Marie-Louise took each Tuesday was destroyed by a bloody bombing of the Rennes railway station. Fortunately this happened on the Mardi Gras holiday of 1943. It was in 1944 at St Pierre des Corps that she found herself under bombardment. She spent an anxious and sleepless night made worse by twenty-four hours without food. During the winter of 1944-45 the trip from Poitiers to Paris meant crossing the Loire river by foot bridge that rising water was on the verge of washing away. Marie-Louise accepted the risks calmly as part of her job.

She succeeded just as well in her academic work. At Poitiers she collected an excellent team of algebraists including Lesieur (1936) and Arbault (1936) who later became professor at Paris XI and at Dijon. Also Croisot who was former student of St Cloud. He, as a young professor at Besançon, was killed in a mountain accident. During the summer of 1947 Paul and Marie-Louise visited Toronto, Yale, and Princeton. In 1953 with the collaboration of Croiset and Lesieur she published Lessons on the theory of lattices, of ordered algebraic structures and geometric lattices which, coming after the fundamental treatise of G. Birkhoff, was favourably cited in later studies including those of Szasz in Hungary and Rutherford in Great Britain. The team of Poitiers algebraists moved toward the "theory of residuation". Molina, who was professor at Nantes and died very young, and Querré, who was later at Brest, both studied the homomorphisms from an ordered semi-group to a graded group following the work of E. Martin. Croisot and Lesieur succeeded in doing what other eminent algebraists had attempted; that is, to explain the noetherian theory of non commutative rings.

Family life for Paul and Marie-Louise became easier and more agreeable since he was at the Faculty of Sciences in Paris. However, the weekly travel between Poitiers and Paris along with her mother's increasing ill-health caused Marie-Louise excessive strain. During 1954-55 she benefited from a post as Research Director at C.N.R.S. After the death of her mother, she returned to Poitiers. Finally in 1956 she, along with Mme Jacqueline Lelong-Ferrand (1936), became the first female mathematicians to be co-opted by the Science Faculty of Paris.

At this time she was studying algebra problems posed by the theory of turbulence. She researched the best averaging operators. She collaborated with Arbault and Molinaro also keeping in touch J. Bassin France, G. Birkhoff and Rota in the U.S.A. Her point of view differed from that of Kampe de Feriet, professor at Lille.

Then she moved toward ordered semigroups and graded groups. She supervised the theses of Ego, who became professor at Réunion, the Scotsman Blyth [who became a professor at St Andrews], Wolfenstein and Bigard, both professors at Le Mans, and Keimel, professor at Darmstadt. Finally she directed the first researches of van Meter, Gerente and Mlle Merlier. (An article dedicated to her memory by L. Lesieur and published by Semigroup Forum expounds her scientific work.)
At the Faculty of Sciences in Paris, the quality of her lecturing, which always went straight to the essentials, attracted many students. They always referred to her by the double name of Mme Dubreil-Jacotin. She knew how to choose excellent collaborators: Lefebvre and Gappy, former students of St Cloud, were part of a team with Bigard. Paul and Marie-Louise published their Lessons in Modern Algebra which sold well and was translated into English and Spanish. Finally the reforms of 1967-68 led Marie-Louise to teach algebra applied to information processing in collaboration with Arsac, Nivat, Schützenberger and their team.

An exemplary professor, a talented researcher and a remarkable supervisor Marie-Louise was able to combine an assured authority and an engaging manner. The perfect balance of her life kept her youthful. She was fortunate to have two grandchildren Emmanuel and Véronique. She and her husband Paul took part in lectures and colloquiums. She preferred those where she could meet only the best. She loved travelling and was delighted to fly over the Grand Canyon in a helicopter. She also explored the bush in Senegal by "deux chevaux" until darkness fell. She took very lively and artistic photographs. She enjoyed playing tennis with her friends as well as bridge, but the sea, and especially sailing, was her first love. Her love of life was exemplified when, in a force six to seven wind she sailed around the Isle of Ré in a "beluga" [a kind of dinghy]. In her memory the Ile de France Yacht Club founded a "Challenge Marie-Louise Dubreil-Jacotin" judged on two contests: a regatta and a bridge tournament.

In October 1970 after alternating periods of hope and despair, their only daughter died in the cruellest way. During the night of 18 and 19th October 1972 Marie-Louise died of a heart attack. Five weeks earlier she had been the victim of a car accident which did not seem to have endangered her life.

The suddenness of these deaths has for too long hidden from us our good fortune in knowing these friends.

Article by L Lesieur (Professor at the University of Paris VI) in Semigroup Forum 6 (1973) 1-2.
Marie-Louise Dubreil-Jacotin, 1905-1972

We can only mourn the death of our colleague Marie-Louise which occurred in October 1972. She was a professor at the University of Paris VI and a member of the editorial board of Semigroup Forum. It is my painful duty to write in the journal a short article about her life and work. It is at the same time a tribute to her memory and a testimony of friendship for her husband Paul Dubreil.

Born in Paris in 1905, Marie-Louise was one of the first French women mathematicians to gain the professional qualifications and status that used to be reserved for men only. She matriculated at the École Normale Supérieure in 1926 (the same class as J. Leray and C. Chevalley). She graduated in 1929 and received her doctorate in Paris in 1934. After her thesis, she was a research assistant at Rennes until 1938 when she became an assistant lecturer. In 1939 she became an associate professor at Lyon until in 1943 she became a full professor at Poitiers where in 1955 she held the chair in Differential and Integral Calculus. It was at Poitiers that I knew her. I am able to confirm that she began the development of this maths department where she amply filled her role as teacher and researcher. She kept the future in mind by gathering around her a community which comprised Arbault, Croisot, and Lesieur. This group was later enriched by others. Among them we must include, for the theory of semigroups, M. P. Schützenberger.

Marie-Louise was appointed to Paris in 1955. In addition to many other tasks she was co-director of the Algebra and Number Theory Seminar and the driving force behind a group actively working on ordered algebraic structures. Her teaching was reorganised to follow new reforms in the curriculum and put her in touch with applied maths and information technology.

Thus, up to the end of her career Marie-Louise had wide ranging interests. We must not forget that her first work was on Fluid Mechanics, directed by H. Villat who has also died this year. Thanks to new methods, she was able to find the exact solution to certain problems in rotational movement or the study of waves in homogenous and heterogeneous liquids. She was also interested in the theory of turbulence and Reynolds' transformations in order to extract from them essential algebraic axioms.

She worked on this with the collaboration of J. Kempe de Feriet and G. Birkhoff, (Algebraic Properties of Reynolds' Transformations, C. R. Acad. Sciences Paris 236 (1952/1953) 1136-38 and 1950-51; Colloque d'Algèbre Supérieure, C. B. R. M. Bruxelles, (1956) 9-27). The theory of distributed lattices, equivalence relations, and methods of algebra also played a role there. The direction of her work was influenced by them. Earlier, in her collaboration with P. Dubreil she had brought to light the notion of permutable equivalences (Théorie algébrique des relations d'équivalances, J. Math. Pures at Appliquées, 18 (1939) 11-35). She also began research into the theory of groups, semigroups and algebraic congruences on her own and in collaboration with P. Dubreil or R. Croisot. Starting in 1948, she dealt with ordered sets by first treating the question of regular equivalences (Bull. Soc. Math. France, 80 (1952) 11-35) and then studying ordered sets under a multiplication law. She introduced the notion of a semi-reticulated semigroup (or "gerbier") just as the equivalence relations allowed her to generalise the ideal theory of Artin-Prüfer. Some of the results she obtained are published in the second part of Lessons on the theory of lattices, of ordered algebraic structures and geometric lattices published in 1953 by Gauthier-Villars in collaboration with R. Croisot and L. Lesieur. [The author] does not have information about further publications, but one should mention a paper on homomorphic image of an ordered semigroup (Bull. Soc. Math. France 92 (1964) 101-115) in which she generalised the work of L. Fuchs (Acta Scient. Math. Szeged XXV (1964)) which was on the same subject.

Mme Dubreil-Jacotin was known as much for her participation in Congresses and Seminars as for her various publications, her text-books or other works. I would like to mention particularly her article on Portraits of women mathematicians (in Important Trends in Mathematical Thought (Les grands courants de la pensée mathématique), published by Cahiers du Sud in 1948, 258-269). There she documented authoritatively the life and work of several women who had left their names on mathematics and she wrote in the introduction, the message that I will use as my conclusion:
The development of the teaching of women, the overturning of prejudices, the profound changes in the kind of life and role assigned to women in recent years have led, without a doubt, to a change in the place held by women in science. One will see how women will be able, on a par with men, to develop from the role of good student or collaborator to become scholars whose work will open new directions.
Translation by Jean O'Connor

Last Updated November 2002