der, demanding the use of all the
soul's powers,

_Oremus._ This exhortation is of very great antiquity, and in this form
is found in the liturgies of St. James and of St. Mark. In those days it
was said by the priest in a loud voice. The priest, the mediator,
following the example of the great Mediator, Christ, calls others to
join with him in prayer. St. Augustine tells us, that sometimes after
pronouncing the word _Oremus_, the priest paused for a while and the
people prayed in silence, and then the priest "collected" the united
prayers of the congregation and offered them to God, hence the name
_collect_ (St. Augustine, Epistle 107), (_cf._ Probst., _Abendl
Messe_, p. 126).

_Invocation and Conclusion_. Prayer is addressed generally to God the
Father. This practice is in accordance with the example and doctrine of
Christ, "Father, I give Thee thanks" (St. John, xi, 41); "Amen, amen, I
say to you; if you ask the Father anything in My name, he will give it
to you" (St. John, xvi. 23). "And He taught us to say 'Our Father.'" In
the early ages of the Church, seldom was prayer addressed to God, the
Son. Innocent III. tells us that the reason for the practice was a fear
that such prayer might lead the catechumens, the Jews or the Pagans
converted to Christianity, to allege or to believe that Christians
worshipped several Gods. However, with the advent of the early heresies,
it became necessary to formulate prayers witnessing the divinity of
Christ and His equality in all things to the Father and the Holy Ghost.
In some of the great prayers of the liturgy, the three Persons of the
Holy Trinity are named to show their equality and unity of nature and
substance. Nearly all the prayers of this kind are the products of the
Church during the storms of early heresy against the divinity, nature or
personality of Christ.

The conclusions of the prayers generally contain the words _Per Dominum
nostrum Jesum Christum_, because all graces come through Jesus Christ,
our Lord and Saviour, Who pleads, as Mediator between God and Man, as He
Himself has said, "No man cometh to the Father but by Me" (St.
John, xiv. 6).

Hence, in every collect, we may distinguish five parts: the invocation,
the motive, the petition, the purpose, the conclusion.

(1) The Invocation takes some form such as _Deus, Domine_.

(2) The motive is commonly introduced by the relative _qui_; e.g., Deus,
_qui corda fidelium sancti spiritus illustratione docuist