For a reader coming to the life and work of Mary Wollstonecraft for the first time, one of the most compelling aspects of her career is its power to unsettle the homosexual/heterosexual split that the twentieth century made so rigid. This unsettling occurs partly because Wollstonecraft, like all eighteenth-century writers, had no words like “homosexual” or “heterosexual” in her vocabulary. Sexuality had no language of its own in the eighteenth century. Instead, writers understood sexual roles through the vocabulary of gender: certain modes of sexual behavior were the supposed prerogatives of masculinity; others, of femininity.

What is so interesting about the eighteenth century is that neither “masculinity” nor “femininity” was a fixed category. When eighteenth-century writers argued about virtually anything (education, aesthetics, law, natural philosophy, religion, politics), they usually did so in loudly gendered terms. However, gender definitions were not necessarily the same in each discourse; they were as likely to differ as to complement one another. Consequently, eighteenth-century writers like Wollstonecraft could set different definitions against each other, using those from one discourse to criticize those in another.