it always like this? The firehouse, our work? I mean, well, once upon a time..."
"Once upon a time!" Beatty said. "What kind of talk is THAT?"
Fool, thought Montag to himself, you'll give it away. At the last fire, a book of fairy tales, he'd glanced at a single line. "I mean," he said, "in the old days, before homes were completely fireproofed " Suddenly it seemed a much younger voice was speaking for him. He opened his mouth and it was Clarisse McClellan saying, "Didn't firemen prevent fires rather than stoke them up and get them going?"
"That's rich!" Stoneman and Black drew forth their rulebooks, which also contained brief histories of the Firemen of America, and laid them out where Montag, though long familiar with them, might read:
"Established, 1790, to burn English-influenced books in the Colonies. First Fireman: Benjamin Franklin."

So Beatty doesn't directly answer Montag's question, but by letting the other men pull out their rulebooks, he implies that their version of history is correct. This, of course, is a lie.

Omitting information is a form of lying. As the oath people say before testifying in court indicates, telling the truth means telling the "whole truth" and not withholding important information.

Beatty receives information about an "alarm-report," alerting the firemen to a house that has books. Beatty takes the address that comes across the telephone, looks at it, and shoves it in his pocket. Even though he only glances at the paper quickly, he knows it is Montag's address. He says, for instance, "This is a special case" as the firemen are leaving. He also drives the Salamander, which he never does. However, he doesn't tell Montag that it is his house they are headed toward.

Instead, he lets Montag experience the shock of realization when they arrive. Beatty seems to take a sadistic pleasure in doing so, because as they pull up, Beatty taunts Montag:

Beatty was watching his face. "Something the matter, Montag?"

As Beatty's conversation with Montag shows, he has known for awhile that Montag is keeping books in his house, but has not confronted him about it. Beatty enjoys playing these kinds of games, which involve keeping Montag in the dark.

The two biggest lies Captain Beatty tells Montag concern the dangers of reading books and the insignificance of pursuing knowledge. When Montag refuses to go to work, Captain Beatty becomes suspicious and visits Montag's home in an attempt to discourage Montag from pursuing knowledge and reading literature. Captain Beatty proceeds to explain to Montag why a society without books and authors is ideal. Captain Beatty then lies to Montag by saying,

"A book is a loaded gun in the house next door. Burn it. Take the shot from the weapon. Breach man's mind" (Bradbury, 28).

Essentially, Captain Beatty lies to Montag by telling him that literature does more harm than good. Beatty believes that education in the literary arts creates division and conflict throughout society, which is a lie. Captain Beatty once again lies to Montag by telling him,

"I've had to read a few in my time, to know what I was about, and the books say nothing! Nothing you can teach or believe. They're about non-existent people, figments of imagination, if they're fiction. And if they're non-fiction, it's worse, one professor calling another an idiot, one philosopher screaming down another's gullet. All of them running about, putting out the stars and extinguishing the sun. You come away lost" (Bradbury, 30).

Captain Beatty's assessment of literature is absolutely false, because individuals can gain valuable perspective on life and insight into the world around them and become enlightened by reading and pursuing knowledge.

Capt. Beatty told Guy lots of lies.  Early in the story, Guy asks, at the firestation, a question that Clarisse had put to him about whether or not the job of fireman had always been about starting fires.  Beatty's implied response is that it is ridiculous to even ask such a question.  That's a lie.  After the woman burned herself with her books, Beatty shows his knowledge of books and lies about it saying that he only knows little bits and pieces.  It becomes clear, further into the story, that Beatty is actually very well read. so his explanation to Guy is a lie.  Some of the biggest lies come when Beatty is talking to Guy before the fire run to Guy's house.  Beatty says that books are traitors because they give opposing viewpoints and he takes quotes out of context to attempt to prove his point.  The reader has to wonder if Beatty isn't actually trying to show Guy just the opposite point - that books open up one's mind to a variety of views.

Montag, upset by the burning of the older woman with her books, lies about the book he has hidden under his pillow when he stays home sick from work the next day. He covers the book up when Beatty comes to his home:

Montag made sure the book was well hidden behind the pillow.

Further on in the conversation, he lies to Beatty, who asks him if he'll come to work for a later shift.

Montag shut his eyes. "I'll be in later. Maybe."

We know he is lying because he thinks:

I'll never come in again.

When someone comes to the door after Montag has revealed his cache of books to Mildred, he refuses to answer, thinking it is Beatty:

The front door voice called again softly. "Someone here . . ."
"We won't answer." Montag lay back against the wall and then slowly sank to a crouching position and began to nudge the books.

These scenes mark a turning point in the novel. Montag lies because his whole orientation to his world has changed. He can no longer live as he has been. He can no longer burn books. Further, although books are illegal and although he is a firefighter, he has collected and hidden them in his house. He feels he can't let Beatty know, though Beatty must know, especially after Mildred almost reveals the book behind the pillow. Montag lies about coming to work, because he can't let Beatty see how upset and disillusioned he is with burning books.

He tries to tell the truth to Mildred, because he knows at this point he is going to turn against his society. He wants her on his side. However, she betrays him and turns him in, and he becomes a fugitive.