That Protestants, that so-called orthodox Protestants at least, profess to hold, and claim as belonging to their Protestantism, many things that are also held by Catholics, nobody denies; but these things are no part of Protestantism, for the Church held and taught them ages before Protestantism was born. They are part and parcel of the one Catholic faith, and belong to Catholics only. Protestants can rightfully claim as Protestant only those things wherein they differ from the Church, which the Church denies, and which they assert; that is, what is peculiarly or distinctively Protestant. We cannot allow them to claim as theirs what is and always has been ours; we willingly accord them their own, but not one whit more. All which they profess to hold in common with us is ours, not theirs. Adopting this rule, which is just and unimpeachable, nothing in fact is theirs but their denials, and as all their denials are, as we have seen, made on no Catholic principle or truth, they are pure negations, and hence Protestantism is purely negative, and consequently is no religion, for all religion is affirmative.
Dr. O. A. Brownson