He is best known as a commentator on the Summa of Thomas Aquinas; he also wrote commentaries on the books of the Old and New Testaments.
In 1606, Capponi was invited to teach theology and Sacred Scripture to the Carthusians in a monastery near Bologna.
The people of Bologna venerated him as a saint; miracles are said to have been wrought through his intercession and his body was taken (1615) from the community burying-ground to be deposited in the Dominican church.
Until the Leonine edition of Thomas Aquinas's works appeared, the Porrecta-Cajetan commentaries were classical.
His principal works are: To the first volume were added: Jacques Échard censures the addition of the Expositio in primam partem and Tractatus de praescientia et praedestinationa of Giovanni Crisostomo Javèlli [it];