In the 2/1/2007 WT, p.6, they chose to put in bold, "Every lie is an untruth, but not every untruth is a lie."
This is the type of thinking that guarantees someone is a liar. In the article, they cherry-pick their definition to excuse the fact that WT has claimed to speak God's promises for what turn out to be false prophecies. They defend themselves by claiming that since they believed it, it wasn't a lie. Duh. And for that matter, how can they dare to call the devil a liar? Adam and Eve learned the difference between good and bad, and they didn't die the same day they ate the fruit, they lived for nearly 1000 years! Satan is a better source of truth than WT is!
Look at ANY religion and you'll find people to believe theirs is the truth! But that doesn't make it the truth. WT will gladly call others liars, but they can't stand to have the finger pointed back at them. So they're not "liars", they're "untruthers." In the end, the results are the same.
Why does WT have to keep releasing new publications and ragazines with "new light"? Because all their old light proved to be LIES!