I heard an what I like to call a swine d'rush yesterday. Just as a pig shows external signs of kashrus and hides the signs that prove him to be as tamei as they come, this speech purported to be a d'var torah, but its content was nothing but apikorsus. I may be particularly sensitive to this brand of chillul HaShem because it was the Union Hagada (sans makkos; not politically correct) that started me on the journey to Truth.
The speaker started by paraphrasing a Moreh N'vuchim, but calling it simply a "Rambam"; you know you are in trouble when that happens. It was the infamous Moreh N'vuchim that the sacrificial system instituted in the Torah because all primitive nations did that and it would have been too hard to tell them to just stop it. That was bad enough. The speaker then went on to say that, "With this principle of the Rambam" -- hang on! no philosophical principle was being promulgated here, it was a specific statement (misquoted) on a specific topic -- "we can say the same thing about slavery." WHAT?!? He took a specific statement out of context from Moreh N'vuchim and then morphed it into a way to claim that the Rambam says anything he finds politically incorrect is simply a concession to a primitive people. Just for the record, the Rambam in the Mishna Torah does not make any apologies for korbanos.
So here's the straight story. There are two kinds of avadim: eved ivri and eved k'na'ani. An eved ivri is a Jew who's work is owned by another Jew for some period of time; basically and indentured servant. That can happen in one of two ways. It could be voluntary; a Jew has fallen on hard times sells himself as an indentured servant to pay off debts. Alternatively, a Jewish thief who cannot repay what he stole may be sold by the court to recompense his victim. This second way speaks volumes about how the Torah views justice. The victim is compensated and the perpetrator is put into an environment where he will be treated with respect while paying off his debt. It is about that sort of eved that Chazal say, "mi sh'kana eved kana rav"/one who acquires a slave acquires a master; the eved ivri must be treated like any other member of the master's family.
Then there is the eved k'na'ani. On the one hand, he is really property; he can be sold, he is inherited when the master dies, he has no rights to own anything -- whatever comes to him is immediately and automatically acquired by the master. Moreover, there is an issur for the master to free the eved (except in certain circumstances; we may discuss that some time).
There is one case where the Torah requires the master to send the eved free with a document of emancipation. That would kick into effect if the master knocked out his tooth or blinded an eye (or permanently damages any of another 22 parts). Nowadays, by the way, he would not go free; this is a Torah imposed fine, and we don't impose fines. Once he is freed, though, he is no longer a goy; he is a full Jew. The Rambam, in fact (in the Mishna Torah), says that this kind of servitude is actually the beginning of a conversion process.
There is nothing at all politically correct about this; not a proof it is true and good, but a reasonable indication.