Piarists, the popular name of a Catholic educational order, the "clerici regulares scholarum piarum," the Pauline Congregation of the Mother of God, founded by Joseph Calasanza (Josephus a Matre Dei) at Rome in the beginning of the 17th century. Calasanza, a native of Calasanz in the province of Huesca in Aragon, was born on September 11, 1556, studied at Lerida and Alcala, and after his ordination to the priesthood removed to Rome (1592). Here he organized, in 1607, a brotherhood which ultimately, in 1617, became an independent Congregation, numbering at that time fifteen priests, under Calasanza as their head. To the three usual vows they added a fourth, that of devotion to the gratuitous instruction of youth. I.n 1622 the Congregation received a new constitution from Gregory XV., and had all the privileges of the mendicant orders conferred upon it, Calasanza being recognized as general. In 1643 the' jealousy of the Jesuits led to his removal from office; owing to the same cause the Congregation was deprived of its privileges by Innocent X. in 1646. Calasanza, who died on August 22, 1648, was beatified in 1748, and canonized in 1767. The privileges of the Congregation were successively restored in 1660, 1669 and 1698. The Piarists, who are not numerous, are found chiefly in Italy, Spain, the West Indies, Germany, and especially in Austria-Hungary. Before the course of study was regulated by the state, a Piarist establishment contained nine classes: reading, writing, elementary mathematics, schola parva or Rudimentorum, schola Principiorum, Grammatica, Syntaxis, Humanitas or Poesis, Rhetorica. The general provost of the order is chosen by the general chapter, and with a general procurator and four assistants resides at Rome. The members are divided into professors, novices, and lay brethren. Their dress is very similar to that of the Jesuits; their motto "Ad majus pietatis incrementum!" For Calasanza, see Timon-David, Vie de St Joseph Calasance (Marseilles, 1884); on the Piarists, P. Helyot, Hist. des ordres religieuses (1715), iv. 281; J. A. Seyffert, Ordensregeln der Piaristen (Halle, 1783); J. Schaller, Gedanken fiber die Ordensfassung der Piaristen (Prague, 1805); A. Heimbucher, Orden and Kongregationen (1897) ii. 271; articles by O. Zockler in Herzog-Hauck's Realencyklopridie fiir protestantische Theologie (1904), vol. xv. and by C. Kniel in Wetzer and Welte's Kirchen-lexikon (1895), vol. ix.