Grave Matter

One of the hardest concepts to explain in RCIA is "grave matter," constituting one of the three conditions necessary for mortal sin.  What is a good explanation of "grave matter"?

  An answer offered by Father Tait Schroeder...

I would refer to Catechism paragraphs 1854-1864 where mortal sin and its three conditions are discussed (grave matter, full knowledge, and deliberate consent). Grave matter deals with offenses against the Ten Commandments. Of course all sins are in some way a deviation from the Ten Commandments, but there are certain sins of greater magnitude than others (think of our discussion of canonical penance - it was done for the gravest of sins - murder, adultery, apostasy).

We also have to think of circumstances when dealing with grave matter. Basically it is a serious offense that goes against the natural moral law or divine law as determined by the Church. As far as I know, there is no set list of what is grave matter, though throughout the Catechism certain sins are listed as serious or grave (e.g. - CCC 2181 - missing your Sunday obligation or CCC 2277 - euthanasia).