This paper is interested first of all in the gender polarities (male-female), as well as the doctrinal ones (heresy-orthodoxy), present in Sicut aquila, that is, the last eight chapters of Suso's Life. However, the theme of heresy had already been touched on in a text from his youth, in particular with regard to Suso's encounter with a ‘nameless wild thing’, whose sex is somewhat uncertain. Various earlier legends evoking similar ‘androgynous encounters’ help us to see that in the Middle Ages the theme of the androgyne also had something to do with the philosopher's stone of the alchemists. In Suso's writing this stone is embodied by Christ, whose iconography contains androgynous characteristics. But the gender polarity of Sicut aquila is expressed above all through a romantic metaphysical flight written in the form of a lovers’ dialogue between Suso - sometimes called Frater Amandus - and his beloved spiritual daughter.