Fahrenheit 451 is a book about a society which tries to reject knowledge and beauty/simplicity of life and promote ignorance and fast-living. Its main protagonist, Guy Montag, who used to burn books, tries to buck that trend. So the book of Ecclesiastes symbolizes knowledge and it also symbolizes change. One main quote is Ecclesiastes 3:1 : "To everything there is a season. " So Ecclesiastes symbolizes the change from ignorance and book burning to knowledge and learning. This theme of renewal and change is also demonstrated by the Phoenix which had to do with the rebirth of humankind after its destruction. The rebirth takes place when Faber - himself a well-read man who burned books - decided to contact a printer and begin producing books
Knowledge is a consistent theme in the novel as Clarisse McClellan is constantly searching for meaning and asks questions and it was she who introduced Montag, a book burner, to this search for knowledge. Also Montag remembers trying to fill a sieve (the human mind) with sand (knowledge).