1. From one point of view, the sacraments are dramatic performances according to a script supplied in outline by Jesus and produced and directed by his Church. Considered this way, they are correctly defined as a kind of sign (see S.t., 3, q. 60, a. 1; q. 64, a. 3).
2. Morality, however, is much more concerned with actions than with outward performances. Thus, insofar as they are principles of Christian life, the sacraments ought mainly to be considered as acts.4 Doing so makes it possible to see how the human acts involved in the sacraments organize all the rest of one’s Christian life. This is the approach emphasized here, with the notion of the sacraments as signs having a subordinate role.
3. Insofar as they involve human acts, the sacraments are cooperative actions in which God the Spirit, Jesus the Lord in glory, the Church by her ordained minister, and the recipient (unless the recipient cannot act) join to accomplish the justification and sanctification of human persons, by extending to them the redemption (from the consequences of sin) and glorification already accomplished by God in Jesus with his human cooperation.
4. The sacraments permit us to become conscious participants not only in the benefits of Jesus’ human redemptive act but in the act itself. They do this by joining several human acts—the redemptive human act of Jesus, the human act of the ordained minister on behalf of the Church, and (normally) the human act of the recipient—to the divine act of restoration and divinization. This divine act first restored Jesus from the dead and glorified his humanity. It is still having its effect in the world, where Jesus’ Spirit is gradually renewing the face of the earth (see S.t., 3, q. 61, a. 1, ad 3; q. 62, a, 5; q. 63, aa. 1, 6; q. 64, a. 1, ad 2; q. 64, a. 6, ad 2; q. 64, a. 8).
5. The recipient’s sacramental act is a moral principle because it organizes the rest of his or her life. A Christian life begins with baptism and is structured by the other sacraments in several distinct but compatible ways, which will be explained when each sacrament is considered.
Of course, the cooperation involved in the sacraments is not that of coequal partners. It is not like the cooperation of a husband and wife in generating and raising children, but more like the cooperation of mother and infant in nursing. The divine act and the human acts which together constitute a unified sacramental act are infinitely different, and even the various human acts which are done by our Lord in glory, the minister for the Church, and the recipient are diverse in kind. God allows us to cooperate in his work, but our role is a subordinate one, ours by his merciful condescension.
The situation is like that of a mother who makes bread for her family and has her small children help. One holds his finger carefully at a place where the mother puts it on the recipe. She could as well or even better use a ruler to keep her place. Another holds the pans to receive the formed loaves. The mother could as well set the pans on the counter. A third watches the clock until the big hand reaches a certain designated point. The mother could more confidently use the automatic timer on the range. Yet the children do help. As a result, they can proudly present their father with a sample of bread when he comes home from work: “We helped mama make it!”
By enlisting the children’s help, the mother actually made more work for herself. She could more easily have baked the bread in the evening after they were all in bed. But she is interested not so much in making bread as in making men and women. Similarly, in redeeming us from sin and perfecting us to glory, God is interested in raising mature members of his family. Our cooperation is not a necessary means to attaining his objective. Rather, it is part of his objective. By the gift of this cooperation God causes us freely to determine ourselves as the humanly fulfilled divine children he wishes us to be forever.5
4. The Eucharist has been treated as action very suggestively (though not in every respect in accord with Catholic teaching) by the Anglican philospher-theologian, J. R. Lucas, Freedom and Grace (Grand Rapids, Mich.: William B. Eerdmans, 1976), 109–19.
5. For a conception of the significance of the sacraments remarkably similar to mine, see Bernard Bro, O.P., The Spirituality of the Sacraments: Doctrine and Practice for Today, trans. Theodore DuBois (New York: Sheed and Ward, 1968), 104–52; note the remarkable statement (124): “It is with an infinite delicacy that God does everything he can to depend on man in the work of salvation, in so far as he can without ceasing to be God [emphasis deleted].” A treatment of the sacraments which subordinates sign to action and emphasizes the primacy of God’s work: Antonio Miralles, “Gracia, fe y sacramentos,” Scripta Theologica, 6 (1974), 299–328.