Summa Theologica

Reply to Objection 3. Names are given to things considered in reference to their end and state of completeness. Now a disposition is not an end, whereas perfection is. Consequently things that signify disposition to holiness are not called sacraments, and with regard to these the objection is verified: only those are called sacraments which signify the perfection of holiness in man.

Thomas Aquinas. Summa theological, III, q.60, in First Complete American Edition in Three Volumes. Vol. 2. Trans. Fathers of the English Dominican Province. (New York,NY: Benziger, 1947), #’s.


In the process of distinguishing sacraments he kind of accidentally defines sacramentals without addressing them directly, and guess what, the distinction is made upon that which disposes and that which perfects and actualizes. This fits in great with what I've been thinking is the primary significance of sacramentals and thus blessings, that by them we may really be disposed, by an operation of grace which disposes, in other words, actual grace.

Van Slyke

Hence blessing or consecrating a thing in general or
water in particular entailed breaking Satan’s influence
over it, so that it could no longer serve as an instrument
of his hate.54 Then, by the power of Christ entrusted
to the Church, the thing blessed could be used as an
efficacious instrument for good – assuming the proper
disposition of the person who benefits from the use of
the item.

- Daniel G. Van Slyke, "The Order for Blessing Water: Past and Present," Antiphon 8, no.2 (2003), 18.

Van Slyke

One scholar of holy water, writing before Vatican
II, expressed quite a different view of the state of
creation in the following passage: “By the fall of our
first parents, the spirit of evil obtained influence not
only over man, but also over inanimate nature, whence
he is called in Scripture ‘the prince of this world’” (Jn
12:31, 14:30, 16:11). For this reason, when the Church
exorcizes some thing, “the curse put upon it is removed,
and Satan’s power over it either destroyed entirely, or
at least diminished.”

- Daniel G. Van Slyke, "The Order for Blessing Water: Past and Present," Antiphon 8, no.2 (2003), 18.

Van Slyke

(the notion) the “liturgy of the world”
could shed light on the general consensus articulated
by many theologians writing on blessings in the post-
Conciliar period: God’s creatures are blessed from their
creation; liturgical blessings are opportunities to praise
and thank God for this, and, from the pastoral
perspective, to edify those present by recalling it.

- Daniel G. Van Slyke, "The Order for Blessing Water: Past and Present," Antiphon 8, no.2 (2003), 18.

Van Slyke

What theological shifts, it may be asked, led to the new understanding that entailed the wholesale rewriting of the Ritual’s blessings? David Stosur reasons that, in the absence of sustained attention given to blessings in and of themselves, “a contemporary theology of blessings . . . must simply be extrapolated from approaches that theologians since Vatican II have taken to the sacraments and to the liturgy in general.”48 He proceeds to do this, appealing particularly to reflections on the liturgy by Otto Semmelroth, Edward Schillebeeckx, and Karl Rahner.

- Daniel G. Van Slyke, "The Order for Blessing Water: Past and Present," Antiphon 8, no.2 (2003), 18.

Dr.Van Slyke's analysis of the theological shift after the council helps me to understand which aspects of the classical theology of blessing are important.

Shetler

Churches and sacred objects can of course be re-consecrated, but only if they lose their blessing by profanation, which does not indicate that the effects of their consecrations were only fallibly produced but rather that through some subsequent effect they were afterwards lost.
The Spanish Jesuits describe the efficacy of sacramentals as follows:
The efficacy of these sacramentals is not ex opere operato, but neither is it ex opere operantis, as if their efficacy were such as the good works of the faithful have. The efficacy of the sacramentals is derived from the fact that they are the petitions of the Church, which, since they are most acceptable to God, are efficacious in a special way; but they do not have their effect infallibly. Therefore the efficacy of the sacramentals is quasi ex opere operato, or ex opere operantis Ecclesiae.

- Joseph Shetler, “Some Contemporary Questions on Sacramentals Considered according to the Scholastic Theology of Their Mode of Efficacy.” (STL Thesis,Angelicum,2007), 18.

Shetler

This quasi-certainty is founded on the Church’s sanctity, which St. Paul calls “holy and immaculate, without stain or wrinkle or anything of that sort.” The Bride of Christ must indeed possess a particularly effective intercessory power deserving of a middle cate-gory between the perfect merits of Christ and the imperfect merits of men.

- Joseph Shetler, “Some Contemporary Questions on Sacramentals Considered according to the Scholastic Theology of Their Mode of Efficacy.” (STL Thesis, Angelicum, 2007), 16.