What IS good, and how do we determine it?

[Metis]

That seems a very odd thing for a Catholic to say Catholic_Lady, whenever I have visited Catholic Forums they usually deny that slavery itself is immoral (if you go to more conservative ones or even SSPX they usually go further and say feudalism/serfdom/absolute monarchy are the only Godly Catholic forms of governance.

I don't see how the Catholic Church can say slavery is immoral, when the Synod of Gangra said anyone who called for the abolition of it was Anathema, several popes have owned slaves (Alexander VI actually granted permission to the Spanish to enslave the inhabitants of South America!) and in more recent times the Pope actually sided with the US confederacy, stating that anyone who thought slavery was immoral was against God. (If you look into the campaign against slavery you'll actually find it was led by protestants and one of it's greatest enemies was no other than the Catholic Church. Look at St Martin de Pores, who was basically made a saint for being a submissive slave and respectful to whitey!)

By all means I agree slavery is immoral, but for most of it's history (until the 1970's to be more precise) Catholicism has held that slavery is instituted by God and that some people are just better than others.

I am not part of the SSPX, and so I cannot speak on their behalf.

Oh I don't expect you to, but they do raise a perfectly valid point and critique the post Vatican-II church for not doing so.

Technically this is still perfectly valid history and previous stances on key issues of morality, so they've either changed what is moral and a sin OR the Catholic Church is still cool with slavery but just likes to keep it quiet.

Don't get me wrong I do think the SSPX are batty, but I do appreciate how truthful they are and how they aren't afraid to actually repeat what encyclicals say; even the really douchy stuff like "the state permitting freedom of religious observance is a sin". I don't see Francis coming out to call the Orthodox and Muslims infidels, but at least Pius IX had the balls to do so. In both counts however it is the teaching of the Catholic Church since the release of the Syllabus of Errors that all non Catholics do not have the freedom to practice their religion.

After all, that's why Salazar (the dictator of Portugal) banned all non Catholic forms of worship. By all means do check. In any case, we're either seeing a lot of deliberately misleading outsiders and Catholics by the Vatican or a huge u-turn on morality. I'm just curious which you think it is.