From the end of the Enlightenment to the 19th century and beyond, french linguists, journalists and authors have fought for and against the acknowledgement of a feminine form for the word « amateur » after it was used by Jean-Jacques Rousseau in its Letters on Botanic. Many claimed that « amatrice » could not be allowed by comparison with the word « auteur », considered as both a masculine and feminine noun – even though « autrice » was used by writers up to the 17th century. The justifications of a reluctance to adopt the word « amatrice » often translate a resistance in acknowledging any king of competence to women. Indirectly, such quarrels are related to the difficulty for women to be recognized as writers at the time. This article shows how gender representations mingle with the evolution of a definition of knowledge, challenged by the ambiguous role of amateurs in science during the 19th century, and the growing visibility of women writers.