INCLINATION (liturgy). - The natural gesture of respect expressed by an inclination has been adopted by Eastern and Western liturgies from the most remote antiquity as an expression of humility, veneration, and adoration. Even today the use of inclination in liturgical ceremonial is much more common in the East than in the West, where, beginning in the 10th-11th centuries, the use of genuflection began to prevail for adoration, a rite originally of a penitential character. Inclination, as an act of adoration, especially at the moment of the elevation of the Host in the Mass, before disappearing from Western ceremonial gave rise to heated polemics, such as that which arose within the Chapter of Lyon in the last quarter of the 16th century.
In the pastoral sermons of St. Caesarius of Arles there is a whole series of references to inclination during prayer (cf. Serm. 72, 76, 77, 152, ed. G. Morin, Opera Omnia s. Caesarii, I, Marcedsous 1937, pp. 303, 305, 306, 589, 591). The Ordo Romanus I (ch. 88, ed. M. Andrieu, II, Louvain 1948, p. 96) and Amalarius of Metz (cf. Liber Officialis, III, 22-23: ed. J. M. Hanssens, Vatican City 1948, pp. 329-30) attest that in the 8th-9th centuries in Rome the clergy stood with heads bowed throughout the duration of the Canon. At the beginning of the rite of the elevation of the Host, Honorius III speaks only of inclination even for the faithful (Potthast, 6163, letter of 19 Nov. 1219). The faithful were to bow particularly to receive the blessing, which is already evident from various passages of Book VIII of the Apostolic Constitutions (cf., e.g., chs. 6, 37, 39 etc.: ed. F. X. Funk, Paderborn 1906, pp. 481, 542, 549). A vestige of this usage, which became common to all liturgies, remains in the Roman Rite in the humilita capita vestra Deo before the recitation of the oratio super populum on weekdays in Lent.
Two kinds of inclination are distinguished: that of the head (the prooecum of the East; the inclinato capite of ancient Ordines) and that of the body (the metavoxa moxa of the East; the permanet inclinati of the Ordines): in the Roman liturgy the former is subdivided into deep, moderate, and slight, the latter into deep and moderate according to the circumstances.