Stefano degli Angeli

Stefano degli Angeli, who lived from 1623 to 1697, was an Italian mathematician, philosopher and Jesuate, born in Venice. He was a member of the Catholic Order of the Jesuats, which was suppressed in 1668, and a student of Bonaventura Cavalieri. From 1662 until his death he taught at the University of Padua. From 1654 to 1667 he devoted himself to geometry, continuing the research of Cavalieri and Evangelista Torricelli on the method of indivisibles, and he then turned to mechanics, where he often clashed with Giovanni Alfonso Borelli and Giovanni Riccioli. In his 1658 book Problemata geometrica sexaginta and in De infinitis parabolis of 1659 he defended indivisibles against the criticisms of the Jesuits Mario Bettini and André Tacquet. James Gregory studied under him in Padua from 1664 until 1668, and Jean-Étienne Montucla praised him in his Histoire des mathématiques.