Whether the imposition of the priest's hands is necessary for this sacrament?

Objections

Objection 1 : It would seem that the imposition of the priest's hands is necessary for this sacrament. For it is written (Mk. 16:18): "They shall lay hands upon the sick, and they shall recover." Now sinners are sick spiritually, and obtain recovery through this sacrament. Therefore an imposition of hands should be made in this sacrament.
Objection 2 : Further, in this sacrament man regains the Holy Ghost Whom he had lost, wherefore it is said in the person of the penitent (Ps. 1:14): "Restore unto me the joy of Thy salvation, and strengthen me with a perfect spirit." Now the Holy Ghost is given by the imposition of hands; for we read (Acts 8:17) that the apostles "laid their hands upon them, and they received the Holy Ghost"; and (Mt. 19:13) that "little children were presented" to our Lord, "that He should impose hands upon them." Therefore an imposition of hands should be made in this sacrament.
Objection 3 : Further, the priest's words are not more efficacious in this than in the other sacraments. But in the other sacraments the words of the minister do not suffice, unless he perform some action: thus, in Baptism, the priest while saying: "I baptize thee," has to perform a bodily washing. Therefore, also while saying: "I absolve thee," the priest should perform some action in regard to the penitent, by laying hands on him.