One of the most rigorous philosophers of biology I have ever known died on 22 September 2008. At the age of 39, Marie-Claude Lorne committed suicide by jumping into the Seine. She left a letter saying she felt that life had nothing more to offer her. The letter described her sense of deep injustice at the failure of the University of Brest, France, to confirm her as an Associate Professor. This decision is extremely rare, even exceptional in France.

Marie-Claude was a specialist in the concept of biological function. Her Ph.D dissertation, Functional explanations and normativity, was written at the Institute Jean Nicod (Paris, France), under the supervision of Joëlle Proust, and defended in 2004. It was hailed as a landmark work on the subject. Jean Gayon, Professor at Paris 1 Pantheon-Sorbonne University, had organized a seminar on biological functions at the Institut d’Histoire des Sciences et des Techniques (IHPST, Paris, France), and Marie-Claude quite naturally became one of the pillars of our group.

Marie-Claude was never satisfied with her work and constantly moved into new areas in the philosophy of biology: the concept of information, the evolutionary significance of symbiosis, the debate on developmental constraints, developmental systems theory, among others. To each of these investigations Marie-Claude brought her signature rigour and intellectual honesty. That refusal to be satisfied, however, also made her reluctant to publish. Several of her friends, admirers of her work, intend to bring Marie-Claude’s writings to the attention of the broader community of scholars. An association, called “Les Amis de Marie-Claude” (“Marie-Claude’s Friends”), will be created soon. Jean Gayon will be its president.

With her good friend Francesca Merlin, Marie-Claude organized our Philosophy of Biology seminar at IHPST (http://philbioihpst.free.fr/philbio.html). Under their talented direction it became, in my opinion, one of the most active and stimulating philosophy of biology groups in the world. In 3 years, Marie-Claude and Francesca brought to the seminar the likes of Lindley Darden, Peter Godfrey-Smith, Paul Griffiths, Eva Jablonka, Evelyn Fox Keller, Philip Kitcher, Tim Lewens, Roberta Millstein, Gerd Müller, Alexander Rosenberg, Elliott Sober, and Kim Sterelny.

To many of us at IHPST, Institut Jean Nicod, and beyond, Marie-Claude was first and foremost a great friend. Her life was hard and filled with intolerable problems. Despite these problems, she loved, and knew, good food and wines. Perhaps her favourite hobby was reading detective novels; she even spoke of writing some day in that genre. She loved concerts, and was herself a musician. She had started to learn violin late, but thanks to her usual and always impressive perseverance she became a good player. She had a passion for Wagner, and sometimes described herself as a ‘romantic’. What many of us remember most vividly is her booming and expressive laugh.

Her friends inside the philosophy of biology community admired her rigour, freedom of thought, and honesty. In addition to Francesca Merlin, these included Frédéric Bouchard (University of Montreal, Canada) Jean-Claude Dupont (University of Picardie, France), and Denis Forest (University of Lyon 3, France); Marie-Claude always spoke of these companions with respect and tenderness.

Marie-Claude Lorne will remain an example to us; she was a true philosopher: critical, never fully satisfied, and always direct. She could be stubborn and uncompromising—even harsh. Certainly these aspects of her character, so central to her integrity as a thinker, made her ill-suited to the French mandarin academic system. The University of Brest’s refusal to confirm her position was not the only cause of her suicide, but it was certainly a major one. The exact nature of these events is now being investigated.

May Marie-Claude rest in peace. Remembering her, we cannot.