The other day one of my newborn sons started to laugh for no reason at all. When this happened I was reminded of something that Metropolitan Hierotheos once said," A monk of the Holy Mountain says that when small children turn their attention in some direction and laugh without a reason, it means that they see their angel. What happens in the lives of saints, for whom it is altogether natural to be with the angels, happens in little children." It really is an amazing concept that some fathers of the Byzantine tradition teach that the smallest amongst us are on the same level of the saints.
Basically, the teachings of the purity of infants is summed up in the following statements of the Metropolitan," Therefore orthodox theology does not teach what theology in the West says, that man inherits the guilt of the ancestral sin. For we believe that at birth a person has a pure *nous: his nous is illuminated, which is the natural state. The inheritance of ancestral sin, as we said in another place, lies in the fact that the body inherits corruptibility and mortality, which, with the passage of time, and as the child grows and passions develop, darkens the noetic part of his soul. Indeed the developed passions linked with corruptibility and mortality and darkness of the environment darken the *noetic part of the souls of children.(taken from his Book: “Life After Death pg 101”) .
The spiritual purity of infants has sometimes been a difficult concept to grasp when trying to understand sin.There really is no overall consensus among the fathers about how we inherit sin and how it effects children. Looking at the history of the Church you will find many different teachings that developed in this regard. For example, the Latin tradition taught the doctrine of limbo for many centuries. The doctrine of limbo proposes that even though babies never sinned they were still under the punishment of original sin and if they died outside of being baptized they would go to limbo.
Even though limbo is no longer a doctrine that's proclaimed on the official level of the Roman Catholic church it demonstrates what the Catechism of the Catholic Church teaches about the nature of sin, "the transmission of original sin is a mystery that we cannot fully understand ccc404". Taking this in consideration I think it's important to recognize that this popular approach of the purity of children found in the Byzantine tradition is not something that contradicts the Roman Catholic tradition of original sin. Rather, it's another approach to that mystery that we "can't fully understand".
A question that sometimes is presented to Byzantine Catholics that maintain child purity is "are you not violating the council of Trent ?". Often this question is presented without fully understanding the nature of Trent. The dogmatic pronouncements of Trent were done mostly in relation to the Latin churches conflicts with protestant Christians. When the dogma of original sin was proclaimed it was for the necessity of the reality of its belief and not to tell the churches of the East that they are wrong.
When people present this question to us some confusion arises in compared to modern Roman Catholic teaching.The council of Trent teaches that babies have sin but there is nothing that alludes to how it effects human nature such as in the case of a personal guilt. For instance Trent teaches," If anyone asserts, that the prevarication of Adam injured himself alone, and not his posterity; and that the holiness and justice, received of God, which he lost, he lost for himself alone, and not for us also; or that he, being defiled by the sin of disobedience, has only transfused death, and pains of the body, into the whole human race, but not sin also, which is the death of the soul; let him be anathema:--" and yet in the Catechism of the Catholic Church we have a further clarification on what was taught at Trent. We read, "original sin does not have the character of a personal fault in any of Adam's descendants ccc405. A teaching that complements the Byzantine tradition regarding the spiritual purity of infants.
Looking at the Catechism of the Catholic Church some might find it contradicting popular trends of thought that developed in the past in the Roman Catholic church. When looking at the Baltimore catechism from 100 years back we find that it says "On account of the disobedience of our first parents, we all share in their sin and punishment,256" or "The loss of the gift of original justice left our first parents and us in mortal sin,258" Like the doctrine of Limbo these are not contradictions but rather developments in trying to understanding the mystery of sin. Today the Roman church no longer teaches limbo, or that we are in mortal sin when we are born, which they did 100 years ago.
It's no mystery in how the Roman Catholic church arrived at its modern developments in understanding the mystery of sin. Only by looking East the Western church was able to develop and fine tune its own teachings. What would have happened if Trent was directed toward the Byzantine churches that held to these teachings? It's obvious that these conclusions of the modern Latin tradition would not be possible and the doctrines such as limbo and being born into mortal sin would be taught at the official level in the Roman church. We have many unique approaches to the mystery of sin found in our Byzantine tradition. Ones that are not at odds with the Roman Catholic tradition but represent different approaches to a shared mystery. We need not be afraid of who we are and what we believe as Byzantine Catholics. Rome needs us to be true to who we are just as much as we need them.
(*For those that don't know Metropolitan Hierotheos definition of nous:
Nous-the word has various uses in Patristic teaching. It indicates either the soul or the heart or even and energy of the soul. Yet, the nous is mainly the eye of the soul; the purest part of the soul; the highest attention. It is also called noetic energy and it is not identified with reason.)