The theme of equal rights for women, as introduced by the punning title, is the most obvious of several closely related themes of the novel. Pratchett puts all the cliches of patriarchy into the mouths of the pompous wizards of Unseen University, lampooning in the process the elaborate hierarchy of higher education. In the different ways appropriate to their different ages and experiences, Esk and Granny Weatherwax challenge the assumptions of the power structure. Although they are represented as being in fact superior to their male counterparts, they are willing to settle for equality — but nothing less.

Pratchett has more in mind than a literary version of the widespread posters and bumper stickers about women's secret superiority. The moderation of the female characters' demands is grounded in the wisdom of Granny Weatherwax. Her magic depends on harmony, not domination. She serves her community as midwife and healer, and she maintains a close and cooperative relationship with the natural world. One of Esk's crucial lessons comes when she tries to take over the body of an eagle; she nearly dies, and learns from Granny that her mistake was in trying to seize the bird's mind instead of gently entering and sharing it. Wizards try to remake the world to suit their purposes and reflect what is inside their heads; Granny Weatherwax practices and teaches a magic that does not distort reality. She is far too wise to desire to dominate, but also too wise to let herself be dominated.

In her education, young Esk becomes the first to combine male and female magic, to be both wizard and witch. The power conferred by the staff left to her by a dying wizard is dangerous, difficult to control; her training in witchery helps her to achieve a balance in herself that ultimately averts catastrophe. The male and female practitioners of magic have been separate too much and too long; Esk represents the possibility of a new synthesis, better than the discrete and often hostile female and male magics of the Discworld before her time.