For example: "Didn't the Catholic Church used to teach that..."
- wolves were the spawn of Satan.
- women had no souls
- left handed people were possessed
- the Pope was God on earth
The inner Catholic in me, whenever I hear these things says:
The outer Catholic, however, needs to be more charitable and say something like, "That is something that I've never heard before as a Catholic. Would you mind showing me where it is that the Church taught this?"
Typically, what evidence will be provided, if anything at all, is either a document written by a random Catholic (priest or layperson), and this is interpreted as "Therefore, the Catholic Church used to teach this."
Or it is something taken out of context and needs to be understood within the lens of the entirety of the manuscript.
Or a reference will be provided that says, "The Catholic Church taught [fill in the blank with the canard du jour]", but no primary source will ever be offered.
In order for something to be a teaching of the Catholic Church, it needs to come from the Magisterium of the Church--that is, the teaching authority of the Church which includes the bishops, in union with the Pope, or a Pope writing to the Church, or an ecumenical council of the Church.
In fact, even if a statement comes from a Pope, it need not be interpreted as a teaching of the Church. It may simply be his personal, theological opinion. One must always look at the context of the writings, the source and the authority with which this particular statement is promulgated. For example, Pope Benedict XVI wrote, in his book Jesus of Nazareth, that he does not believe that the Gospel of John was written by the Apostle John.
That is his theological opinion only. For a person to read that statement by Pope B16 and conclude, "The Catholic Church believes that the Gospel of John was not written by the Apostle John" would be erroneous.
For more info on how the claim that the Catholic Church taught that women had no souls circulated, see this article:
The Myth of Soulless Women