A reader writes:
I’ve never heard the term "presumption of faith" used before but in thinking about the issue of Bishops withholding Communion from wayward politicians, it strikes me that the Church applies almost universally this principle (expressed in other ways).
Like presumption of innocence in court, the Church presumes faith when one asks for any of the sacraments. Because we cannot know another’s heart as God can, we have to take their word that they are able to receive the sacrament and believe what the sacrament does.
In the case of communion, it has been said many times that the confessional is empty and the communion lines are full. Logic, knowledge of human concupiscence, and just the results of some of the most recent surveys of Catholics tells us that there is something wrong with the picture, but in the communion line the Church applies presumption of faith because she has to.
It is only where a person publically advertises their sin and just as publically seeks communion while demonstrating no purpose of amendment (a requisite for a good confession if that confession had indeed taken place privately), it is only in that kind a circumstance that a public response is required to avert scandal.
Others holding the same views privately and acting upon those views could receive communion in an unworthy manner and the priest or bishop may never know because they are acting on the presumption of faith.
And so on.
Does that make any sense as a concept?
It does, though I’d tweak it a bit.
There is indeed a presumption that the Church makes in admitting people to Communion, though it isn’t just a presumption that they have faith. It also presumes that they meet the other requirements for Communion, such as being in a state of grace, having the proper dispositions, having fasted for an hour before the moment of Communion, and so forth. These are summed up under the heading of "worthiness to receive Communion" (which is a bit paradoxical given that immediately before Communion we say "Lord, I am not worthy to receive you," but there we are). I’d therefore phrase the presumption as a presumption of worthiness rather than a presumption of faith.
This presumption holds except in very specific cases. A Catholic presenting himself for holy Communion is not to be denied except unless he is prohibited by law from receiving. The Code of Canon Law provides:
Can. 912 Any baptized person not prohibited by law can and must be admitted to holy communion.
Now, there are people who are prohibited by law from receiving (e.g., because they’re in mortal sin, because they haven’t fasted, etc.), but in the practice of the Church the evaluation of these criteria is left to the individual communicant in the vast majority of cases. The only time in the Code that priest and other ministers of Communion are told not to give Communion to a person who presents himself is in the following canon:
Can. 915 Those who have been excommunicated or interdicted after the imposition or declaration of the penalty and others obstinately persevering in manifest grave sin are not to be admitted to holy communion.
Since declared excommunications (as opposed to automatic excommunications) and declared interdicts are as rare as hen’s teeth, the most commonly triggered part of this canon is that concerning "others obstinately persevering in manifest grave sin." That means people who are publicly known to be involved in grave sin and who refuse to amend their ways.
As a practical matter, only those individuals are denied Communion (if even they are). Otherwise the presumption of worthiness to receive holy Communion operates.