In his first work, published in 1747, Immanuel Kant cites the ideas of another philosopher: a scholar of Newton, religion, science, and mathematics. The philosopher, whose work had been translated into several languages, is Émilie Du Châtelet.

Yet despite her powerhouse accomplishments—and the shout-out from no less a luminary than Kant—her work won’t be found in the 1,000-plus pages of the new edition of The Norton Introduction to Philosophy. In the anthology, which claims to trace 2,400 years of philosophy, the first female philosopher doesn’t appear until the section on writing from the mid-20th century. Or in any of the other leading anthologies used in university classrooms, scholars say.

Also absent are these 17th-century English thinkers: Margaret Cavendish, a prolific writer and natural philosopher; Anne Conway, who discusses the philosophy of Descartes, Hobbes, and Spinoza in The Principles of the Most Ancient and Modern Philosophy (which is influenced by the Kabbalah); and “Lady” Damaris Masham—the daughter of a Cambridge Platonist and a close friend of John Locke who published several works and debated ideas in letters she exchanged with the German mathematician and philosopher G.W. Leibniz.

Despite the spread of feminism and multiculturalism, and their impact on fields from literature to anthropology, it is possible to major in philosophy without hearing anything about the historical contributions of women philosophers. The canon remains dominated by white males—the discipline that some say still hews to the myth that genius is tied to gender.

Andrew Janiak, an associate professor of philosophy at Duke University, was a graduate student in the 1990s when he came across Kant’s startling reference to Madame Du Châtelet. “I remember thinking: Did he really mean Madame?” Janiak said. “It was the only time I’d seen a philosopher refer to the ideas of a woman.”

Now, Janiak and a team of Duke students and researchers, along with colleagues at Columbia and the University of Pennsylvania, have launched a site that features the forgotten voices of women philosophers, giving academics and students a rare opportunity to study and promote their work. Project Vox, as the site is called, posts texts and translations of 17th-century women philosophers' work, as well as suggested syllabi for college courses featuring that work. The site is open-source, meaning that faculty and students from around the world can contribute and use materials, and has a 10-member international advisory board. According to Janiak, “a long list of folks” has already contributed or requested syllabi from the project, which went live in March.

Project Vox aims to address the lack of easy-to-find resources for faculty and students who have been eager to add women to their courses but have had few sources on which to draw. While Margaret Atherton’s 1994 collection, Women Philosophers of the Early Modern Period, does focus on these women, it only features essays about the work of several individuals. A comprehensive critical edition or anthology of women’s contributions to that era doesn’t appear to exist. (Janiak is now co-editing a series with Christia Mercer of Columbia and Eileen O’Neill of the University of Massachusetts.)

Adela Deanova, a Ph.D. candidate at Duke, joined the initiative last year, taking on the often-challenging task of tracking down women’s writings. Few of their works are in mainstream journals, Deanova said; most appear as chapters in history or literature books or in private letters. Translating works written in other languages into English, she added, also makes them more accessible. “A lot of the information is obscure, so we want to present it in ways that are helpful to researchers and instructors,” she said. Deanova, who is writing a dissertation that in part focuses on Cavendish's critique of Robert Boyle and Robert Hooke, is now translating 12 letters that Leibniz wrote in French to Masham.

Funded by a humanities grant to Duke, Project Vox launched with the work of the four aforementioned women, who Janiak said made historic contributions to science and philosophy but whose writing had been relatively neglected. Their ideas were published and debated in their day, influencing some of the male canonical heavyweights: Henry More, Francis Mercury Van Helmont, and Leibniz, for example, praised Conway’s works. And while being a women kept Du Châtelet out of university life and membership in the Royal Academy of Science, she turned her home, the Chateau de Cirey, into a salon for European scholars across disciplines. She published Foundations of Physics, which was hotly debated and included passages that were featured—without attribution—in one of the most  influential publications of the French Enlightenment: Diderot and D’Alembert’s Encyclopédia.

Overlooking these women’s contributions doesn’t just misrepresent the era, it’s also helped solidify philosophy’s status as a white men’s club. About 35 percent of U.S. philosophy faculty members in 2009, the most recent year for which reliable data is available, were women, and just 30 percent of the doctorates awarded that year went to women, according to data from Humanities Indicators, a project of the American Academy of Arts & Sciences. The numbers are similar across the globe, including in the United Kingdom, Australia, and Canada. Moreover, the percentage of women with philosophy doctorates hasn’t changed much over the years; in 1987, for example, females accounted for 20 percent of the doctorates in the U.S.

“We certainly see that women have been systematically left out of the canon, and that women coming in have not been able to see how much influence women have had in the field,” said Amy E. Ferrer, the executive director of the American Philosophical Association. “There were women doing important work, and that needs to be acknowledged.” Indeed, it’s an issue that in the past few years has gotten a lot more attention both within and outside of philosophical circles, said Ferrer, who cited efforts such as the APA’s summer diversity institute for students and mentorship programs at some universities for junior female faculty.

Deanova said she became acutely aware of how few women were in the discipline when she decided on a career in academia. Studying the contributions of female philosophers can help women more easily picture themselves in the field, but “we don’t want people to add women to a course for politically correct reasons,” Deanova said. “We want them to teach these works because they are important part of this time period, and if you are not teaching them, you are not giving students an accurate picture of what went on.”

As for why historical female works were buried after they’d been so widely shared, that’s a question without a clear-cut answer. In the case of Du Châtelet, Janiak says the philosopher’s reputation shifted over the years from that of a writer to that of a translator, an activity that was deemed more socially appropriate for an intellectual woman.

Even Voltaire, with whom she’d had a very public and long-lasting relationship, played a role in minimizing her legacy. He’d praised her intelligence and ideas in some works, but after she died at age 43, Voltaire also referred to her as translator and framed her thoughts as derivative, according to Janiak. “She had understood science in a way he didn’t,” Janiak said. “I think he was jealous.”