Beatty says that fire’s real beauty is that it destroys consequences.
When Montag steals the book, he does not really think about the consequences. It is like the book is asking him to take it, so he takes it. That one move changes the rest of his life. From then on, he lives with a new awareness, but also in fear.
Beatty, the fire captain and Montag’s boss, is aware that Montag is a book thief and is questioning society. Rather than punishing him right away, he decides to toy with him. He waits until the consequences fall on Montag. He does give him lectures about why society eliminated books, especially when Montag does not come to work.
Beatty got up. "I must be going. Lecture's over. I hope I've clarified things. The important thing for you to remember, Montag, is we're the Happiness Boys... We stand against the small tide of those who want to make everyone unhappy with conflicting theory and thought. (Part I)
He knows that the consequences will catch up to Montag eventually if he continues on his path, which is against society’s rules (and current moral code). They do. Mildred turns him in, even though he is her own husband. This is when Beatty, in a philosophical and someone sarcastic comment, reminds Montag about another aspect of fire.
What is fire? It's a mystery. Scientists give us gobbledegook about friction and molecules. But they don't really know. Its real beauty is that it destroys responsibility and consequences. A problem gets too burdensome, then into the furnace with it. (Part III)
In his society, houses are fireproof. If someone has a book, you just burn the whole house down, sometimes with the person in it. Society has just decided to burn all of its problems, rather than face them. It's part of the same disease that made them decide to eliminate books in the first place.