Reply Obj. 1: The life of grace unto which a man is regenerated, presupposes the life of the rational nature, in which man is capable of receiving instruction.
Reply Obj. 2: Just as Mother Church, as stated above (Q. 69, A. 6, ad 3), lends children another's feet that they may come, and another's heart that they may believe, so, too, she lends them another's ears, that they may hear, and another's mind, that through others they may be taught. And therefore, as they are to be baptized, on the same grounds they are to be instructed.
Reply Obj. 3: He who answers in the child's stead: "I do believe," does not foretell that the child will believe when it comes to the right age, else he would say: "He will believe"; but in the child's stead he professes the Church's faith which is communicated to that child, the sacrament of which faith is bestowed on it, and to which faith he is bound by another. For there is nothing unfitting in a person being bound by another in things necessary for salvation. In like manner the sponsor, in answering for the child, promises to use his endeavors that the child may believe. This, however, would not be sufficient in the case of adults having the use of reason. _______________________
SECOND ARTICLE [III, Q. 71, Art. 2]
Whether Exorcism Should Precede Baptism?
Objection 1: It seems that exorcism should not precede Baptism. For
exorcism is ordained against energumens or those who are possessed.
But not all are such like. Therefore exorcism should not precede
Baptism.
Obj. 2: Further, so long as man is a subject of sin, the devil has power over him, according to John 8:34: "Whosoever committeth sin is the servant of sin." But sin is taken away by Baptism. Therefore men should not be exorcized before Baptism.
Obj. 3: Further, Holy water was introduced in order to ward off the power of the demons. Therefore exorcism was not needed as a further remedy.
On the contrary, Pope Celestine says (Epist. ad Episcop. Galliae): "Whether children or young people approach the sacrament of regeneration, they should not come to the fount of life before the unclean spirit has been expelled from them by the exorcisms and breathings of the clerics."
I answer that, Whoever purposes to do a work wisely, first removes the obstacles to his work; hence it is written (Jer. 4:3): "Break up anew your fallow ground and sow not upon thorns." Now the devil is the enemy of man's salvation, which man acquires by Baptism; and he has a certain power over man from the very fact that the latter is subject to original, or even actual, sin. Consequently it is fitting that before Baptism the demons should be cast out by exorcisms, lest they impede man's salvation. Which expulsion is signified by the (priest) breathing (upon the person to be baptized); while the blessing, with the imposition of hands, bars the way against the return of him who was cast out. Then the salt which is put in the mouth, and the anointing of the nose and ears with spittle, signify the receiving of doctrine, as to the ears; consent thereto as to the nose; and confession thereof, as to the mouth. And the anointing with oil signifies man's ability to fight against the demons.