The following entry from Abbot Vonier's study seemed apropos following on Barbara Dent. The human will can make only feeble motions on its own, unstrengthened by grace. We can keep at a work no more than a moment or two without God's strength behind us.
from A Key to the Doctrine of the Eucharist
Abbot VonierThe Eucharist ought really to illuminate for us all the other sacraments with its own radiance. The Eucahrist is the sun in the firmament of sacramental grace. Is there not, however, sometimes a danger on the one hand of giving the Eucharist a position such as would hardly retain it in its sacramental setting, while on the other hand there may be the greater peril of our lowering the status of the other sacraments to conventional forms of lesser spiritual power? Yet the Eucharist ought to safeguard for us all the spiritual glories of the other sacraments, by keeping them within the orbit of the divine Presence; while they in turn, being as truly sacraments, although they do not contain the Body and Blood of Christ, will enable us to see even the Eucharist in its true perspective. We may put it in the following way: One sacrament, while remaining entirely a sacrament, and indeed through its sacramentality, and not as an unusual feature or external adjunct, contains the true Body and Blood of Christ; it does this in virtue of its sacramental state, not because it is more than a sacrament. (p. 42-43)
(book available from Zaccheus Press)
And for Vonier and the believing Catholic the importance of the Eucharist being a sacrament is that it is a sign that effects what it signifies. A sacrament is not merely an external ritual or an empty ceremony, but it is a sign that contains the fullness of the meaning of the sign. It is a symbol that causes what it symbolizes to enter reality and transform it. In short, it is a sign that bestows grace and has as its object the bestowal of grace, the strengthening of the connection between creator and creation.
