[1177.] (1.) The Essential Complement is a dative of the person or thing added to an idea which is felt as incomplete without the dative ([1180]).
Thus, pāret, he is obedient, is a statement which is felt as incomplete without a dative added to denote what it is he is obedient to, in the sentence pāret senātuī, he is obedient to the senate. But when stress is put on the action merely, without reference to its bearing, such a verb may be used without a dative: as, pāret, he is obedient, he yields obedience.
[1178.] (2.) The Optional Complement, that is, the dative of interest, advantage, or disadvantage, adds something to an idea that is already complete in itself ([1205]).
Thus, carmina cantō, I chant verses, is a statement entirely complete in itself; it may be modified or not, at option, by a dative, thus: carmina virginibus puerīsque cantō, verses for maids and boys I chant.
[1179.] II. The dative of certain substantives is used predicatively ([1219]).
[I. THE COMPLEMENTARY DATIVE.]
[(1.) THE ESSENTIAL COMPLEMENT.]
[1180.] Many verbs require a dative to complete their meaning.