Eternal sin
Thomas Aquinas lists, or has responded to, six sins that supposedly go against the Holy Spirit:
Thomas Aquinas explains that the unforgivability of blasphemy against the Holy Spirit means that it removes the entrance to these means of salvation; however, it cannot hinder God in taking away this obstacle by way of a miracle.
Original sin
In Swedenborgianism, exegesis of the first 11 chapters of Genesis from "The First Church", has a view that Adam is not an individual person. Rather, he is a symbolic representation of the "Most Ancient Church", having a more direct contact with heaven than all other successive churches. Swedenborg's view of original sin is referred to as "hereditary evil", which passes from generation to generation. It cannot be completely abolished by an individual man, but can be tempered when someone reforms their own life, and are thus held accountable only for their own sins.