Saint Theresa of Avila is the Christian mystic whose experiences of ecstasy are cited by the author as examples of how moments of physical and spiritual transcendence, occurring within the context of intense prayer, meditation and faith, parallel similar moments of transcendence experienced by those moving through sexual ecstasy. In other words, the author is suggesting that the intensity of Theresa's feelings is akin to the intensity of feeling experienced during the moment of orgasm.