Ignatius thought of Miss Trixie and said, "Yes, there is one."
"She appears to be."
Mrs. Reilly winked at Ignatius and threw her overcoat on top of the cupboard. (3.218-222)
This is one of Ignatius's most gratuitous lies. Why bother pretending that Miss Trixie is a cute girl? It's hard to believe he actually cares whether his mother thinks he has a girlfriend, or might have a girlfriend. Maybe he just figures it will make her happy and so keep her off his back? Or maybe he just likes lying.
As soon as the office manager went through the door, Ignatius rolled a sheet of Levy stationery into Mr. Gonzalez' high black typewriter. If Levy Pants was to succeed, the first step would be imposing a heavy hand upon its detractors. (4.75)
Ignatius sets about committing fraud. The odd thing is that this, his biggest, most consequential lie, appears to come from something like honest motives. He wants to help Levy Pants; he's trying to be a good employee. To some extent. Though it seems likely, too, that he just really enjoys insulting people and telling fibs, and can't pass up the chance to do both at once.
"You tell a cop by his eyes, Darlene. They're very self-assured. I been in this business too long. I know every dirty cop angle. The marked bills, the phony clothes. If you can't tell by the eyes, then take a look at the money. It's full of pencil marks and crap." (5.6)
Lana Lee explains that cops are deceivers. As a criminal, Lana practices a certain amount of deception herself, so it seems like she should know whereof she speaks, but then toward the end of the novel, she gets fooled. Oops.
"I wonder how many of our 'military' are simply people like your friend, disguised tarts."
"Who knows? I wish they all were."
"Of course," Ignatius said in a thoughtful, serious voice, "this could be a worldwide deception. The red sateen scarf rode up and down. The next war could turn out to be one massive orgy." (10.162-164)
Ignatius contemplates achieving peace through the massive worldwide deception of having gay men infiltrate the armed forces. In some sense, Ignatius is here suddenly recognizing the existence and the potential of the closet—the fact that gay people have long concealed their identities in order to avoid persecution or stigma. Ignatius, lover of deception that he is, is excited by the possibilities.
It doesn't seem to occur to him that if gay men in the military were going to bring peace, it would have happened long ago, since gay men have served in the military since there has been one.
He picked up the telephone, and in an assumed voice rich with Mayfair accents said, "Yus?"
"Mr. Reilly?" a man asked.
"Mr. Reilly is not here." (11.447-449)
Ignatius lies to Mr. Levy. It's not clear that Ignatius even knows why Mr. Levy is trying to find him, and instead he just lies on general principle, either because he assumes he's in trouble, or possibly just to be a jerk. Or maybe because the novel thinks lying is fun?
Lana looked at the silk suit, the hat, the weak, insecure eyes. She could spot a safe one, a soft touch, all right. A rich doctor? A lawyer? She might be able to turn this little fiasco into a profit. (12.319)
Lana's hawk eyes fail her, and after boasting early in the novel that she can always detect a cop, she is completely bamboozled by one of Mancuso's silly costumes. Even liars get taken in on occasion, apparently.
"But he says he didn't write this."
"An obvious untruth. His every word is false. He speaks with a forked tongue!" (13.228)
Ignatius tries to blame Mr. Gonzalez for writing the letter to Abelman. What Ignatius says is pretty much true… as a description not of Gonzalez, but of himself. It's he who is speaking an obvious untruth; it's he whose every word is false.
So he had written it after all. Mr. Levy looked tenderly down at the little accused party snoring over her box of Dutch cookies. For everyone's sake, he thought, you will have to be declared incompetent and confess, Miss Trixie. You are being framed. Mr. Levy laughed out loud. Why had Miss Trixie confessed so sincerely? (13.323)
Ignatius's lie turns out best for everyone. This is maybe the point in the novel that shows most clearly that Confederacy doesn't really make a moral stand against lies or liars. It's not a book about how those who deceive get what's coming to them, and the novel instead seems to appreciate a good whopper for its audacity. Especially good lies, it suggests (at least in this case) should be rewarded.
"This is Ignatius Reilly," he said when Santa had answered. "Is my mother coming down there tonight?"
"No, she ain't," Santa replied coldly. "I ain't spoke with your momma all day."
Ignatius hung up. Something was going on. (14.51-53)
Santa isn't a particularly good liar. Why not just admit that Mrs. Reilly is coming over? Or, if she doesn't want to do that, why not keep quiet about the rest of it? In her eagerness to bamboozle Ignatius, she lets him know something's up, since he overheard his mom talking to Santa earlier. Lying isn't easy, and it takes practice. Maybe that's why Ignatius lies even when it doesn't seem like he has to—he doesn't want to get out of shape.