By Br. Stephen, MIC, Marian Fathers of the Immaculate Conception - When the name of Teresa of Avila comes to mind, many people think first of her great spiritual work, The Interior Castle. Teresa herself, with her high degree of mental prayer, seems like a kind of interior castle: She is hidden, concealed from the average Catholic by high and fortified walls which are (more obscurely still) spiritual walls. Even St. Therese of Lisieux, her fellow Carmelite, was initially put off by the grand portrayal she was given of Teresa of Avila, choosing instead her well-known “little way.”