I use grave to denote whenever something is intrinsically evil but I don’t know if the person did a mortal sin. If someone says a “white lie” knowing it is grave matter to lie and has full intent to do it, it is a mortal sin.
No.
While all lies are intrinsically evil, not all lies are mortally sinful, even if the person telling them is fully aware of their malice, and fully wants to tell them. Small lies, such as “white lies” or lying about a small matter, are only venial sins. I don’t advocate this — I don’t approach sin as though
“I will avoid mortal sin at all cost, but venial sins, I won’t make as great an effort to avoid them” — but I will not say that all lies, for instance, how pretty Aunt Hortense’s new hat is even though you think it’s irredeemably ugly, are mortal sins. The Church does not say this, and I do not say this. Not all intrinsically evil things are mortal sins. Stealing trivial amounts of goods is not mortally sinful (not condoning, just stating). Everyday small lapses in charity (i.e., sins against the Fifth Commandment) are not mortally sinful. And so on.
I am very concerned that the recent trend (after Vatican II) to throw around the term “grave matter” is leading people to think that vast categories of sins, sins that
do admit of parvity of matter, are all mortal sins. It is as though a whole new lexicon of mortal sins is being created, under the rubric of calling them “grave matter”.
That’s the kind of “modern-day Jansenism” I resist.
No way the person who told lies about trivial matters in the OP committed a mortal sin.
