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But it is our teaching that there is only one ecclesia, and not two, and that this one and true Church is the assembly of men bound together by the profession of the same Christian faith and the communion of the same sacraments, under the rule of the legitimate pastors, and especially that of the Roman Pontiff, the one Vicar of Christ on earth.  From this definition it is easy to infer which men belong to the Church and which do not belong to it.  There are three parts of this definition; the profession of the true faith, the communion of the sacraments, and the subjection to the Roman Pontiff, the legitimate pastor.

   By reason of the first part all infidels, both those who have never been in the Church, such as Jews, Turks, and pagans; and those who have been in it and have left it, as heretics and apostates, are excluded.  By reason of the second part catechumens and excommunicated persons are excluded, because the former are not yet admitted to the communion of the sacraments, while the latter have been sent away from it.  By reason of the third part there are excluded the schismatics who have the faith and the sacraments, but who are not subject to the legitimate pastor and who thus profess the faith and receive the sacraments outside [of the Church].  All others are included [within the Church in the light of the definition] even though they be reprobates, sinful and impious men.

   Now there is this difference between our teaching and all the others [the “definitions” offered by the various heretics, and discussed in the first section of this second chapter of the De ecclesia militante], that all the others require internal virtues to constitute a man “within” the Church, and hence make the true Church invisible.  But, despite the fact that we believe that all the virtues, faith, hope, charity, and the rest, are to be found within the Church, we do not think that any internal virtue is required to bring it about that a man can be said absolutely to be a part of the true Church of which the Scriptures speak, but [that what is required for this] is only the outward profession of the faith and the communion of the sacraments, which are perceptible by the senses.  For the Church is as visible and palpable an assembly of men as the assembly of the Roman people or the Kingdom of France or the Republic of the Venetians.

   We must note what Augustine says in his Breviculus collationis, where he is dealing with the conference of the third day, that the Church is a living body, in which there is a soul and a body.  And the internal gifts of the Holy Ghost, faith, hope, charity, and the rest are the soul.  The external profession of the faith and the communication of the sacraments are the body.  Hence it is that some are of the soul and of the body of the Church, and hence joined both inwardly and outwardly to Christ the Head, and such people are most perfectly within the Church.  They are, as it were, living members in the body, although some of them share in this life to a greater extent, and others to a lesser extent, while still others have only the beginning of life and, as it were, sensation without movement, like the people who have only faith without charity.

   Again, some are of the soul and not of the body, as catechumens and excommunicated persons if they have faith and charity, as they can have them.

   And, finally, some are of the body and not of the soul, as those who have no internal virtue, but who still by reason of some temporal hope or fear, profess the faith and communicate in the sacraments under the rule of the pastors.  And such individuals are like hairs or fingernails or evil liquids in a human body.

   Consequently, our definition takes in only this last way of being in the Church, because this is required as a minimum in order that a man may be said to be a part of the visible Church.  [De ecclesia militante, c. 2.]