There are many people who are now reading the Fathers of the Church and the Summa Theologica. I was asked a question why St. Thomas’ teachings are not given a more prominent place in the Church. I was surprised. I said that they were but the person wanted the Summa up there with the Catechism of the Catholic Church and the Bible. I think we need to get things straight. There is a difference between official revelation and theology — that which is infallible are the teachings of Christ in the Scripture and Sacred Tradition. These teachings are put together in a comprehensive manner in the Catechism of the Catholic Church, which saw its latest expression at the end of the last century. The Church never sets out to teach a theology. It sets out to teach us truths that have been revealed through Jesus and the Church.
What is theology? Theologies are attempts to explain the teachings of the Church. In some instances, specific theological explanations were officially accepted to explain truths within the Catholic Church. For example, the Church had officially accepted the idea of transubstantiation as the explanation on how bread and wine become the Body and Blood of Christ at the Council of Trent. This idea was mooted as far back as the 11th century but not accepted until the 17th century Council. Theological opinions will always be accepted so long as they are not contrary to the truths expressed in Scripture and Tradition. However, they would always be opinions until they are officially (and thus, infallibly) pronounced as part of the deposit of faith. Thus, between the 11th and 17th centuries, transubstantiation had been accepted as a legitimate way of explaining the Real Presence. There was no necessity to accept it as infallible so long as the truth of the Real Presence was believed. It was only in the 17th century, at the Council of Trent, that one had to accept that transubstantiation is the way the bread and wine changes into the Body and Blood of Christ.
Doesn’t this mean that the Church teachings have changed and is thus not infallible? Of course not. Infallibility doesn’t mean cannot change. It means that the teaching is free from error. Unchangeable and error-free are different things altogether. The truths that the Church teaches do not change in the sense that they are true one day and not true the next. However, the way we understand the workings of the truths can change in that we increase the depth of understanding. Thus, while the body of teaching remains the same body of teaching, there is growth in that there is increase.
So, the Summa Theologica is not supposed to be taken on the same level as the Catechism or the Scriptures. For the most part, the work remains a valid way of explaining the truths taught by Jesus, those yet to be officially accepted as part of the infallible teaching remain opinions.
The Catechism mentioned here is the official Catechism of the Catholic Church. Many catechisms published as textbooks for Sunday School or RCIA formation programmes may contain valid theological opinions that should not be considered as official teaching of the Church. An example of this is the question of Limbo. At the earlier part of his pontificate, Pope Benedict XVI suggested that there was no need for the theological opinion that Limbo exists. Some people began to say that the Pope was trying to change the Catechism and the age old teaching of the Church. In reality, the idea of Limbo was never a part of the infallible teaching of the Church. It was a valid theological opinion to explain where babies who were aborted went. These babies could not be baptised, and thus, not able to enter heaven, nor could we say that they were guilty of personal sins that would cause them to be condemned to hell. Some theologians suggested the possibility of a place called Limbo where these souls could go to. They fashioned this place after the Jewish idea of Sheol which we see in the Old Testament (e.g. Gen 37:35; Is 38:10)