In his personal journal earlier this week (a locked post, so I am not linking to it), an atheist friend mockingly posted about the new seven deadly sins. A rather snarky conversation broke out in the comments among several people of an anti-Catholic bent. Sister Mary Martha did a good job with her commentary on the story itself, but I want to address one of the remarks that appeared in the journal. Since it was a locked post, I will keep this quote anonymous.
I guess the argument is that, if you're not sure whether it's a sin or not, you offend God by running the risk. It might be a sin, but you don't care; you're ignoring the question entirely, and even God can't stand to be ignored.
I was annoyed by the assumption that blindly faithful religionists don't devote any intelligent thought to this issue. In fact, any well-catechized Catholic (sadly, a rara avis these days) can provide the answer. (In all fairness, the comment was in regard to an unfortunately worded quote by the head of the Apostolic Penitentiary.)
When in doubt as to whether something is a sin or not, we can arrive at the solution ourselves with confidence that we are not offending God. He asks we do only two things:
1. Follow our consciences.
2. Make every effort in good faith to form our consciences according to his teachings.
Of course, many people have a firm grasp on #1 while wholly ignoring #2. It should be obvious that we need to form our consciences, though; after all, even the worst criminal can twist his malformed conscience to justify his evil acts.
Formation of conscience can include referring to the Catechism, asking priests and other catechetical authorities, and generally remaining well-informed on Catholic teaching on those issues that cause us trouble.
Although lots of rules can be specified for any particular moral question -- rules upon rules, until we are drowned in scrupulous rules -- a basic, organic approach, a "rule of thumb", is these two steps. This is what I follow. Step two is the ongoing work of a lifetime, and that preparation is what makes step one work.