Thomassin (Discipline de l'Eglise, tom. iii. p. 311 - 374) has copiously treated of the origin, abuses, and restrictions of these tenths. A theory was started, but not pursued, that they were rightfully due to the pope, a tenth of the Levite's tenth to the high priest (Selden on Tithes; see his Works, vol. iii. p. ii. p. 1083).