Latria is a theological term (Latin Latrīa, from the Greek , latreia) used in Eastern Orthodox and Roman Catholic theology to mean adoration, a reverence directed only to the Holy Trinity. Latria carries an emphasis on the internal form of worship, rather than external ceremonies.
Latria also applies to the Eucharist and Eucharistic adoration. In the 16th century, the Council of Trent made specific affirmations of the presence of Christ in the Eucharist and the theological basis for Eucharistic adoration and stated:
"The only-begotten Son of God is to be adored in the Holy Sacrament of the Eucharist with the worship of "latria", including external worship.
Pope Paul VI's 1965 encyclical Mysterium fidei: also affirmed this belief and in items 56 stated:"The Catholic Church has always displayed and still displays this latria that ought to be paid to the Sacrament of the Eucharist, both during Mass and outside of it".
Latria is sacrificial in character, and may be offered only to God. Catholic and Orthodox Christians offer other degrees of reverence to the Blessed Virgin Mary and to the Saints; these non-sacrificial types of reverence are called hyperdulia and dulia, respectively. In English, dulia is also called veneration. Hyperdulia is essentially a heightened degree of dulia provided only to the Blessed Virgin.
This distinction, written about as early as Augustine of Hippo and St Jerome, was detailed more explicitly by Thomas Aquinas in his Summa Theologiae, A.D. 1270: "Reverence is due to God on account of His Excellence, which is communicated to certain creatures not in equal measure, but according to a measure of proportion; and so the reverence which we pay to God, and which belongs to latria, differs from the reverence which we pay to certain excellent creatures; this belongs to dulia, and we shall speak of it further on (103)"; in this next article St. Thomas Aquinas writes: "Wherefore dulia, which pays due service to a human lord, is a distinct virtue from latria, which pays due service to the Lordship of God. It is, moreover, a species of observance, because by observance we honor all those who excel in dignity, while dulia properly speaking is the reverence of servants for their master, dulia being the Greek for servitude".