Objection 1: It would seem that the whole body should be anointed in this sacrament. For, according to Augustine, the whole soul is in every part of the body (On the Trinity 6.6). Now this sacrament is given chiefly in order to heal the soul. Therefore, the whole body ought to be anointed.

Obj. 2: Further, the remedy should be applied to the part affected by the disease. But sometimes the disease is general, and affects the whole body, as a fever does. Therefore, the whole body should be anointed.

Obj. 3: Further, in baptism the whole body is dipped under the water. Therefore, in this sacrament the whole body should be anointed.

On the contrary, According to the rite observed throughout the Church, in this sacrament the sick man is anointed only in certain fixed parts of the body.

I answer that, This sacrament is shown to us under the form of a healing. Now bodily healing has to be effected by applying the remedy not to the whole body, but to those parts where the root of the disease is seated. Consequently, the sacramental unction also ought to be applied to those parts only in which the spiritual sickness is rooted.

Reply Obj. 1: Although the whole soul is, as to its essence, in each part of the body, it is not as to its powers which are the roots of sinful acts. Hence certain fixed parts have to be anointed, those, namely, in which powers have their being.

Reply Obj. 2: The remedy is not always applied to the part affected by the disease, but, with greater reason, to the part where the root of the disease is seated.

Reply Obj. 3: Baptism is given under the form of washing: and a bodily washing cleanses only the part to which it is applied; for this reason baptism is applied to the whole body. It is different with extreme unction for the reason given above.