"The Pope said so"

Pope John Paul II's Apostolic Constitution Fidei Depositum, written in 1992, states:

“The Catechism of the Catholic Church, which I approved 25 June last and the publication of which I today order by virtue of my Apostolic Authority, is a statement of the Church's faith and of catholic doctrine, attested to or illumined by Sacred Scripture, the Apostolic Tradition and the Church's Magisterium. I declare it to be a sure norm for teaching the faith and thus a valid and legitimate instrument for ecclesial communion… This catechism is given to them that it may be a sure and authentic reference text for teaching catholic doctrine and particularly for preparing local catechisms.”

That's more than sufficient to show you or anyone else what the Church teaches. The pope said so. This is how our authority structure works.

http://socrates58.blogspot.com/2008/10/dialogue-with-protestant-on.html

Let’s apply the same authority structure to another papal proclamation:

The Ad Extirpanda of Pope Innocent IV (1252)

We decree that the head of state, whatever his rank or title, in each dominion, whether he is so situated at present,or to be so in the future, in Lombardy, Riviera di Romagnola, or Marchia Tervisina must unequivocally and unhesitatingly swear that he will inviolably preserve, and during his entire term of office see to it that everybody, both in his diocese or administrative domain and the lands subject to his power, shall observe, both what is written herein, and other regulations and laws both ecclesiastical and civil,that are published against heretical wickedness. And the oaths concerning these precisely-observed regulations and laws are to be accepted by whoever succeeds to the monarchical or gubernatorial dignity. Whoever defaults in this regard shall lose the character of head of state or governor. Heads of state and rulers so acting will lose absolutely all guarantees of non-aggression from other governments. No one is obliged to offer fealty to such persons, or ought to do so, even if, afterwards, they submit by swearing the oath. If any head of state or ruler refuses to obey, each and all, these statutes, or neglects them, besides the stigma of forswearing, and the disaster of eternal infamy, he shall undergo the penalty of seeing his country lose its borders,{4} which penalty shall be imposed on him irrecoverably; the country will be converted to common use,{5}because, specifically, a man forsworn and infamous, and, in effect, a protector of heretics, his faith compromised, has usurped the dignity and honor of governmental power; nor shall another head of state or ruler from anywhere replace him, or in any way, by any means, take to himself the vacated dignity or public office.

At the commencement of his term of office,at the assembly of citizens convoked as is the custom, by the authority of the city or feudal domain, the head of state or ruler of the city or feudal domain shall accuse of criminal conduct all heretics of both sexes, no matter by what name they appear on the rolls of citizens. And he will confirm his right to the office inherited from his predecessor in this manner. And furthermore, that no heretical man or woman may dwell, sojourn, or maintain a bare subsistence in the country,or any kind of jurisdiction or district belonging to it,whoever shall find the heretical man or woman shall boldly seize, with impunity, all his or their goods, and freely carry them off, to belong to the remover with full right, unless this kind of removing is restricted to persons designated by law.

Those who are thus appointed may and should seize the heretical men and women and carry off their possessions and cause these to be carried off by others,and take the heretics,or cause them to be taken, into the custody of the Diocesan bishop or his surrogates, and see to it that these things are fully accomplished as well in the diocese as in its entire jurisdiction and district.

The head of state, or whatever ruler stands foremost in the public esteem,must cause the heretics who have been arrested in this manner to be taken to whatever jurisdiction the Diocesan, or his surrogate,is in, or whatever district, or city,or place the Diocesan bishop wishes to take them to.

When the Diocesan, or his surrogate, or the inquisitors commissioned by the Apostolic See, arrive on their missions, the head of state and his vassals and other assistants will lend aid and will faithfully perform their duty with them. Anyone, moreover, whether he is present in the country or sent for to obtain his assistance there, whether in the state or in its jurisdiction, or any district of any kind, will be bound to give the aforesaid officials and their assistants counsel and help when they are trying to arrest a male or female heretic, or seize such a person's belongings, or gather evidence; or enter a house, or a manor, or a hideaway to arrest heretics, on pain of paying 25 pounds in Imperials as a penalty or fine on their former loyalty changing, in whatever manner,to dereliction; the government of a city shall pay a hundred pounds, a manorial domain fifty imperials in coin.

Whoever shall have the audacity to arrange the escape from custody of a male or female heretic,or shall try to prevent the arrest of such a person: or shall prevent the entry of an official into any house, or tower, or any place to hinder arrest, or prevent the gathering of evidence concerning such persons, shall have all his goods,according to the law at Padua when Frederick was emperor there,{6} consigned to the state in perpetuity,and the house that was barred against the official shall be levelled with the ground and its rebuilding prohibited, and the belongings found therein shall be awarded to the officials making the arrest; and if the heretics are found as a result of this prohibition or special preventive measure, the borough shall forfeit to the state two hundred pounds; localities both of the boroughs and the state fifty Imperials, unless within three days the would-be liberator or liberators of the heretics are brought before the head of state for a personal interview.

Those convicted of heresy by the aforesaid Diocesan Bishop,surrogate or inquisitors, shall be taken in shackles to the head of state or ruler or his special representative, instantly,or at least within five days, and the latter shall apply the regulations promulgated against such persons.{7}

If at any time a non-heretical man or woman state that heretics in custody, who have already confessed, are no heretics; or if perhaps the non-heretics demand that the aforesaid fraudulent persons should be released from life imprisonment,though they are nevertheless convicted heretics and must be acknowledged such; the persons who create this snare, accordingly to the aforesaid law shall resign all their property to the state in perpetuity.

The head of state or ruler must force all the heretics whom he has in custody,{8} provided he does so without killing them or breaking their arms or legs,as actual robbers and murderers of souls and thieves of the sacraments of God and Christian faith, to confess their errors and accuse other heretics whom they know, and specify their motives, {9} and those whom they have seduced, and those who have lodged them and defended them,as thieves and robbers of material goods are made to accuse their accomplices and confess the crimes they have committed.

The head of state or ruler must send one of his aides, chosen by the Diocesan if there is one,with the aforesaid inquisitors obtained from the Apostolic See, as often as they shall wish, into the jurisdiction of the state and the district. This aide,as the aforesaid inquisitors shall have determined, will compel three men or more, reliable witnesses,or, if it seem good to them, the whole neighborhood, to testify to the aforesaid inquisitors if they have detected any heretics, or want to expose their motives,{9} whether the heretics celebrate rites in secret gatherings, or scoff at the common life of the faithful, and their customs; or if the witnesses want to expose those the heretics have seduced, or their defenders, or those who lodge them, or those who give the heretics help. The head of state shall proceed against the accused according to the laws of the Emperor Frederick when he governed Padua.

None of these sentences or punishments imposed on account of heresy, shall,either by the motion of any public gathering, the advice of counselors, or any kind of popular outcry,or the innate humanity {10}of those in authority,be in any way waived or pardoned.

Notes to the Translation

{7} I.e., he shall burn them alive. See Introduction.

_{8} Omnes haereticos quos captos habuerit. All the male heretics the state has in custody must be tortured to make them confess their crimes and reveal their accomplices. The masculine inflection appears generic, cf. omnes haereticos utriusque sexus in Law 2; ad haereticos extirpandos in Law 33. So women too were tortured.

http://userwww.sfsu.edu/~draker/history/Ad_Extirpanda.html