I disagree that theft is only grave matter based on the item being of great value (relative or absolute). First of all, the exceptions commonly made for theft being a venial sin is when the item is of small value. And there is a lot of items that fall in-between being of great value and small value.
Secondly, the intent to do harm to the owner, is of primary importance. And one can do harm, via theft, from a owner even when stealing something of small value.
Your understanding is too lax, IMO. I would say, in general theft is grave matter; but there are exceptions.
I don’t think we actually disagree. My explanation is simplified for this specific case put forth by a specific, presumably very young, poster. I absolutely agree that great value can be more than a dollar sign. That is what is meant by
relative great value. If the O.P. had stated he/she had stolen someone’s inexpensive but necessary medication, well, then obviously it is of great relative value, and my response would not have been the same. If that was done with malice and forethought, then yes, it is certainly worse! You’re absolutely right that malice and forethought heightens the gravity of sin. Usually, stealing with the intent to cause harm entails that one was stealing something of great relative value, if not absolute value. Still, I think it is at least theoretically possible to commit a mortal sin of stealing without the intent to do harm to the owner, and also to commit a venial sin of stealing with the intent to do harm to the owner.
Here, I’ll put forth a case for you for the second one. I was at a fast food restaurant, and saw three teenage boys together. One said, “I’m going to the washroom. X, don’t touch my food. Y, guard it for me.” While he was gone, the other two boys laughed, and each ate a fry. The boy came back and his buddies told him they each ate a fry (presumably just to make him mad, because they told him when he came back). Now presuming there are no complicating factors (poverty, health issues, etc.) and that the other two boys did this just to bug him (wanting to make him angry is the intent to do harm), is this necessarily a mortal sin? (I am not trying to minimize the wrongness of so-called “pranks” that involve taking what doesn’t belong to us. Obviously they are against both God’s law, and civil law, and are very, very wrong, but I don’t think that they are necessarily what the Church would call mortal sins.)
But I appreciate your feedback and thanks for clarifying
