Instruction on the Sacraments in General.
Y Sacrament is meant an outward sign of inward grace, or a sacred and mysterious sign and ceremony ordained by Christ to convey grace to our souls.
The Sacraments may be compared to channels which convey water from a fountain-head, and the soul to a vessel which one carries to these channels to be filled. The fountain, abounding with water, courses through the channels and fills every vessel which is applied thereto, as far as it can hold; the larger the vessel, the greater the quantity of water it will contain. So the larger the capacity of the soul (which capacity depends upon the soul's dispositions), the greater the portion of grace which it receives through the heavenly channels of the Sacraments. But the conditions required in the receiver are by no means productive of the efficacy of the Sacraments. Take the example of light and heat: fire is not lacking in burning power because it cannot act on incombustible materials; nor are the windows of a room the cause of light, though necessary to give it admission.
The Church has never instituted, and could not institute, any Sacrament—this is a power reserved to God Himself. He alone is the Fountain of Grace:390
