Sebastiano del Piombe and Michelangelo in Rome: Problems of the Style and Meaning in the Viterbo Pietà (Ph.d. Rutgers the State University of New Jersey-New Brunswick, 1999, 231 pp.).

'The dissertation is to analyse Sebastiano del Piombo's Pietà (oil on panel, Viterbo, Museo Civico). A collaborative work with Michelangelo, who provided Sebastiano with the inventions of the figures, the Pietà was received by contemporaries as one of the most important works of the Cinquecento, a reputation-making painting... The role of the patron of the Pietà (Giovanni Betonti, a cleric, for his funerary chapel in S. Francesco alla Rocca in Viterbo), a secretary of Cardinal Raffaele Riario and a friend of the Augustinian theologian Egidio da Viterbo, is considered in light of significant archival discoveries. The iconography of the Pietà is interpreted in relation to the patron's devotion to the miraculous Madonna Liberatrice of Viterbo (preserved in the Augustinian church SS. Trinità there) and to Augustinian spirituality. St. Augustine himself is also fundamental in the interpretation of the most striking element of the Pietà, that is Mary's masculinity. Her masculine appearance is explained as imago dei, the conveiling of Mary's spiritual self in the image of God'.