What does the Catechism really say?

Confession and Communion
.
A priest on another blog wrote his views regarding mortal sin, contrition and the reception of Holy Communion in cases where the penitent has not gone to confession.  His comment went something like this:
.

A person can can never be sure if he is in the state of mortal sin. A person might understand he committed a grave or serious sin but the sin can only be mortal when combined with full knowledge and consent of the will, - and often, these dispositions can be mitigated.

Now if the person is conscious of grave sin, ordinarily he should not receive Holy Communion until he has confessed and received sacramental absolution. However, in certain circumstances some people may not be able to get to confession, and or, refraining from reception of Communion can sometimes be a cause for speculation and or embarrassment for the person not to receive.
.
This is my personal opinion, but I say that if a person is guilty of serious sin, despite the fact through no fault of his own is unable to confess, and if he is sincerely sorry for his sin and he desires to receive Holy Communion, a good Act of Contrition accompanied by a firm and practical plan to make his confession at the next available opportunity, the person can receive Holy Communion worthily. - Priest**

.
Now I think I understand what the priest is saying, although I believe his advice may better be left in the confessional, under the heading of 'pastoral care for a particular individual in extraordinary circumstances'. Consider especially that sometimes people just want to avoid confession and look for good excuses to do so - and we can often convince and excuse ourselves of anything.
.
That said, I have to disagree with the proposal we can never be sure we are in a state of mortal sin - I think we can be fairly certain at least.  What we can never be sure of is whether or not we are in the state of grace - unless we have the assurance of sacramental absolution.  If a person is aware of grave sin - I think I'd rather err on the side of caution and confess my sin, rather than risk making a sacrilegious Communion.
.
Better safe than sorry.
.
Fear of embarrassment never should be a reason to receive Communion while aware of unconfessed mortal sin.  The Catechism clearly lays out the conditions for receiving Communion in the ordinary circumstances:
.

1457 According to the Church's command, "after having attained the age of discretion, each of the faithful is bound by an obligation faithfully to confess serious sins at least once a year."56 Anyone who is aware of having committed a mortal sin must not receive Holy Communion, even if he experiences deep contrition, without having first received sacramental absolution, unless he has a grave reason for receiving Communion and there is no possibility of going to confession.57  -

.
To be fair, Father may well be considering that the person, though aware of having committed a mortal sin, albeit not totally certain, yet nevertheless possessing and expressing perfect contrition for the sin, accompanied by a firm purpose of amendment and resolute determination to avoid that sin in the future, may indeed approach Holy Communion with the intention of confessing at the next possible opportunity.  That may have been Father's point which accords with the Catechism:
.

1452 When it [contrition for sin] arises from a love by which God is loved above all else, contrition is called "perfect" (contrition of charity). Such contrition remits venial sins; it also obtains forgiveness of mortal sins if it includes the firm resolution to have recourse to sacramental confession as soon as possible.51 - CCC 

.
However - if one cannot be certain of one's state of soul, how can one be certain one is perfectly contrite?
.
You do not have to receive Holy Communion at every Mass.
.
Anyway - I think in our age of drama and crisis, some people mistake 'grave reason' for otherwise trivial and vain circumstances.  Catholics are not required to receive Holy Communion at every Mass they attend.  We do not have to communicate daily or at funerals and weddings.  A Catholic shouldn't worry about what other people think if one doesn't receive Communion.  Catholics are obliged to assist at Mass on Sundays and holy days of obligation - they are not obliged to communicate.  In fact, the only requirement for Catholics to receive Holy Communion is once a year - commonly referred to as the Easter Duty. 
.
Of course I may be wrong, but I believe the rules pertaining to the reception of Holy Communion are so lax as it is, I'm not sure taking such a liberal approach to sacramental confession in cases of mortal sin beforehand is the best idea - danger of death and other special situations being separate issues of course.
.
Addendum:
.

1415 Anyone who desires to receive Christ in Eucharistic communion must be in the state of grace. Anyone aware of having sinned mortally must not receive communion without having received absolution in the sacrament of penance.
.
1417 The Church warmly recommends that the faithful receive Holy Communion when they participate in the celebration of the Eucharist; she obliges them to do so at least once a year. - CCC  

 
.
**Please note:  I changed the wording somewhat because I do not want to identify the priest - I am simply using the thoughts he expressed to paint the background for my post - what does the catechism really say - this isn't an 'attack'.  Thanks.