Christ instituted the sacraments of the new law. There are seven: Baptism, Confirmation (or Chrismation), the Eucharist, Penance, the Anointing of the Sick, Holy Orders, and Matrimony. The seven sacraments touch all the stages and all the important moments of Christian life:1 they give birth and increase healing and mission to the Christian’s life of faith. There is thus a certain resemblance between the stages of natural life and the stages of the spiritual life.
Following this analogy, Chapter One will expound the three sacraments of Christian initiation; Chapter Two, the sacraments of healing; and Chapter Three, the sacraments at the service of communion and the mission of the faithful. This order, while not the only one possible, does allow one to see that the sacraments form an organic whole in which each particular sacrament has its own vital place. In this organic whole, the Eucharist occupies a unique place as the “Sacrament of sacraments”: “all the other sacraments are ordered to it as to their end.”2
Cf. STh III, 65, 1.
STh III, 65, 3.