Gail Tulloch analyses John Stuart Mill’s The Subjection of Women as a pioneering work in liberal feminism in this 1989 article. As Tulloch shows, Mill’s account challenged contemporary thinking in the society that simplistically and emphatically regarded men and women as naturally different. In particular Mill focused in his challenge on boys and girls’ ‘conditioning’, what might today be called ‘socialisation’, in the midst of sexist beliefs and legal and social practices. Given such conditioning, Mill argued that scholars were in a weak position to empirically evaluate the relative capacities of women and men. Assuming instead a form of agnosticism, lacking evidence beyond the contemporary gender-unequal social system, Mill concluded that there was no compelling reason to presume that women are not equal to men; and girls and women should thus be given opportunities equitably alongside boys and men to develop themselves and contribute to society. After examining the philosophical roots of Mill’s views and the social context of Mill’s consideration, Tulloch explores the implications and insights of Mill’s view for the current context, in which, as Tulloch observes, structural factors continue to result in an inequitable distribution of opportunities for development, education, and professional standing for girls and women.