Apologeticae sive Theologiae Fundamentalis, Tomus II (Pars Altera): Demonstratio Catholica

1. Explanation. Theological conclusions in the widest sense are propositions which are inferred by a process of reasoning from revealed premises. They are, however, of three kinds: a) Conclusions which are inferred by reasoning of any sort whatsoever from two revealed premises, e.g. Christ is to be adored; but Christ is really present in the Eucharist; therefore the Eucharist is to be adored. Such propositions are properly or formally revealed, as is evident.

b) Conclusions which are inferred by a merely explicative reasoning from two premises, of which one is revealed and the other naturally certain, e.g. Christ is a man; but every man has a rational soul; therefore Christ has a rational soul. It is clear that this conclusion is contained in the revealed premise alone, as a part in the whole, and therefore the process of reasoning affords no new motive of assent. Whence even such propositions are properly or formally revealed.

c) Conclusions which are inferred by a deductive or rigorous process of reasoning from one revealed premise and another naturally certain one, e.g. the Son is the Word of God; but the Word of God proceeds from the intellect of God; therefore the Son proceeds from the intellect of God. This conclusion is contained in both premises; and because the conclusion follows the weaker part, it cannot be held as a truth properly or formally revealed, but at most can be called virtually revealed on account of its intimate connection with revelation. These propositions are strictly called theological conclusions, of which we are speaking.

2. Proof. That the Church is infallible in establishing and adjudicating theological conclusions is proved from the end of infallibility and from the practice of the Church.

a) From the end of infallibility. The Church cannot preserve the revealed deposit inviolably unless it is infallible in establishing and adjudicating theological conclusions. For between the revealed principles and the theological conclusions deduced from them there exists such a logical connection that from the falsity of the conclusions the falsity of the principles would necessarily follow. Therefore the Church is infallible with regard to theological conclusions.

b) From the practice of the Church. The Church has frequently established or adjudicated theological conclusions peremptorily. Thus the Council of Constance against Wycliffe and Hus; Pius V against Baius; Pius VI against the Pistorians and the Jansenists; Pius IX against modern errors; Pius X against the modernists condemned propositions, among which not a few theological conclusions are found. But by this manner of acting the Church vindicated for herself infallibility in actual exercise. Therefore she is to be held infallible in these matters. The argument is confirmed by the manner of acting of the faithful, who never failed to give obedience and absolute assent to these judgments of the Church.

Related to theological conclusions are: