MICHELE di SANT'AGOSTINO. - Carmelite theologian, in the world van Ballaert, b. at Brussels on 15 Apr. 1621, d. there on 2 Feb. 1684. He taught philosophy and theology and three times held the office of superior of the Flemish-Belgian province.
His principal work, Institutionum mysticarum libri 4 (3 vols., Antwerp 1671), gathers together, developing them in a more systematic manner, the previously published treatises,
namely: Introductio in terram Carmeli et gustatio fructum illius (Brussels 1659); Pia vita in Christo pro incipientibus, proficientibus et perfectis (there 1661, in Flemish; there 1663, in Latin); Introductio (Mechelen 1669), in Flemish, which alone comprised four treatises concerning total self-denial and renunciation of creatures, the deiform and divine life, the Marian life, and adoration in spirit and truth. Of singular merit is the treatise De vita Mariae-formi et Mariana in Maria propter Mariam, which outlines perfect devotion to the Virgin, published in 1671 (Italian trans., 2nd ed., Rome 1950). The work of Fr. M. di S. A. is characterized by profound theological learning, solid mystical experience, and most tender Marian piety.