Council of Trent on Original Sin
1. If any one does not confess that the first man, Adam, when he had transgressed the commandment of God in Paradise, immediately lost the holiness and justice wherein he had been constituted; and that he incurred, through the offence of that prevarication, the wrath and indignation of God, and consequently death, with which God had previously threatened him, and, together with death, captivity under his power who thenceforth had the empire of death, that is to say, the devil, and that the entire Adam, through that offence of prevarication, was changed, in body and soul, for the worse; let him be anathema.
2. If any one asserts, that the prevarication of Adam injured himself alone, and not his posterity; and that the holiness and justice, received of God, which he lost, he lost for himself alone, and not for us also; or that he, being defiled by the sin of disobedience, has only transfused death, and pains of the body, into the whole human race, but not sin also, which is the death of the soul; let him be anathema:--whereas he contradicts the apostle who says; By one man sin entered into the world, and by sin death, and so death passed upon all men, in whom all have sinned.
Humanis Generis Paragraphs 37-39
37. When, however, there is question of another conjectural opinion, namely polygenism, the children of the Church by no means enjoy such liberty. For the faithful cannot embrace that opinion which maintains that either after Adam there existed on this earth true men who did not take their origin through natural generation from him as from the first parent of all, or that Adam represents a certain number of first parents. Now it is in no way apparent how such an opinion can be reconciled with that which the sources of revealed truth and the documents of the Teaching Authority of the Church propose with regard to original sin, which proceeds from a sin actually committed by an individual Adam and which, through generation, is passed on to all and is in everyone as his own.
38. Just as in the biological and anthropological sciences, so also in the historical sciences there are those who boldly transgress the limits and safeguards established by the Church. In a particular way must be deplored a certain too free interpretation of the historical books of the Old Testament. Those who favor this system, in order to defend their cause, wrongly refer to the Letter which was sent not long ago to the Archbishop of Paris by the Pontifical Commission on Biblical Studies. This letter, in fact, clearly points out that the first eleven chapters of Genesis, although properly speaking not conforming to the historical method used by the best Greek and Latin writers or by competent authors of our time, do nevertheless pertain to history in a true sense, which however must be further studied and determined by exegetes; the same chapters, (the Letter points out), in simple and metaphorical language adapted to the mentality of a people but little cultured, both state the principal truths which are fundamental for our salvation, and also give a popular description of the origin of the human race and the chosen people. If, however, the ancient sacred writers have taken anything from popular narrations (and this may be conceded), it must never be forgotten that they did so with the help of divine inspiration, through which they were rendered immune from any error in selecting and evaluating those documents.
39. Therefore, whatever of the popular narrations have been inserted into the Sacred Scriptures must in no way be considered on a par with myths or other such things, which are more the product of an extravagant imagination than of that striving for truth and simplicity which in the Sacred Books, also of the Old Testament, is so apparent that our ancient sacred writers must be admitted to be clearly superior to the ancient profane writers.
New Catechism which references the dogmatic decree of Trent.
Reference 265 Cf. Council of Trent: DS 1513; Pius XII: DS 3897; Paul VI: AAS 58 (1966), 654.
A. The first man and woman were Adam and Eve.
Q. 234. Are there any persons in the world who are not the descendants of Adam and Eve?
A. There are no persons in the world now, and there never have been any, who are not the descendants of Adam and Eve, because the whole human race had but one origin.