CathInfo.com

Comparing an unbaptized person to an excommunicated one is totally wrong.  An unbaptized person, spiritually speaking, has more in common with a pagan than any catholic.  Excommunication would be more like to a person in schism.  The Catholic encyclopedia explains it thus.  Take note that an excommunicated person is cut off from the SOCIAL and PUBLIC aspects of the Church only.  It does not affect his potential to obtain heaven, whereas an unbaptized person has no right to heaven, being he is not a child of God.


Excommunication (Latin ex, out of, and communio or communicatio, communion — exclusion from the communion), the principal and severest censure, is a medicinal, spiritual penalty that deprives the guilty Christian of all participation in the common blessings of ecclesiastical society. Being a penalty, it supposes guilt; and being the most serious penalty that the Church can inflict, it naturally supposes a very grave offence. It is also a medicinal rather than a vindictive penalty, being intended, not so much to punish the culprit, as to correct him and bring him back to the path of righteousness. It necessarily, therefore, contemplates the future, either to prevent the recurrence of certain culpable acts that have grievous external consequences, or, more especially, to induce the delinquent to satisfy the obligations incurred by his offence.

Its object and its effect are loss of communion, i.e. of the spiritual benefits shared by all the members of Christian society; hence, it can affect only those who by baptism have been admitted to that society. Undoubtedly there can and do exist other penal measures which entail the loss of certain fixed rights; among them are other censures, e.g. suspension for clerics, interdict for clerics and laymen, irregularity ex delicto, etc. Excommunication, however, is clearly distinguished from these penalties in that it is the privation of all rights resulting from the social status of the Christian as such. The excommunicated person, it is true, does not cease to be a Christian, since his baptism can never be effaced; he can, however, be considered as an exile from Christian society and as non-existent, for a time at least, in the sight of ecclesiastical authority. But such exile can have an end (and the Church desires it), as soon as the offender has given suitable satisfaction. Meanwhile, his status before the Church is that of a stranger. He may not participate in public worship nor receive the Body of Christ or any of the sacraments. Moreover, if he be a cleric, he is forbidden to administer a sacred rite or to exercise an act of spiritual authority.