masterjedi747:
Oh, I love that show.

(Which example were you referring to specifically, by the way?)
I forget now exactly what example. I do remember that it was one of the episodes in the second season of “24”. Incidentally, during the third season of “24” the same type of moral dilemma appeared in the form of killing. President Palmer was forced by a terrorist to make a decision to have one of his CTU agents (Agent Ryan) killed, unless the terrorist would release a weaponized virus and kill millions of Americans. To make a long story short, President Palmer ordered Jack Bauer to kill Agent Ryan and deliver the body to the terrorist in order to save millions. Needless to say, Jack Bauer delivered.
To get back on track of this original tread…
The Catechism defines a lie as “speaking a falsehood with the intention of deceiving” (2482). It goes on to say in paragraph 2483 “to lie is to speak or act against the truth in order to lead someone into error”.
Case 1: It appears that if you were not to tell the truth to A in order to keep A from committing murder then not telling the truth would not be a lie. It would not be a lie because by not telling the truth you keeping A from committing an error (i.e., murder). In this case if it still considered a lie (which is a sin) it appears to be a venial sin because of the lack of gravity.
Case 2: Also vice versa: if you were silent (an act) or you told the truth you would cause A to murder thus leading someone (A) into error. And, if in this case it is considered a lie (because you lead someone into error by telling the truth or your silence) it appears to be a mortal sin because of the gravity of the error.
It’s apparent that giving this situation Case 1 is the moral choice. Is there any way out of this situation without committing any sin?