 Broader currents in society have influenced the ways in which scholars and activists have approached research into sexuality and same-sex attraction. Some early 20th century researchers and equality advocates, seeking to vindicate same-sex relations in societies that disparaged and criminalized it, put forward lists of famous historical figures attracted to persons of the same sex. Such lists implied a common historical entity underlying sexual attraction, whether one called it ‘inversion’ or ‘homosexuality.’ This approach (or perhaps closely related family of approaches) is commonly called essentialism. Historians and researchers sympathetic to the gay liberation movement of the late 1960s and 1970s produced a number of books that implicitly relied on an essentialist approach. In the 1970s and 1980s John Boswell raised it to a new level of methodological and historical sophistication, although his position shifted over time to one of virtual agnosticism between essentialists and their critics. Crompton’s work (2003) is a notable contemporary example of an essentialist methodology.