It means that firefighters have the ability to hide the freedom and individuality of themselves and the population.
Explanation:
This question is about the book "Fahrenheit 451". In this book, firefighters are charged with burning any book that is found with any citizen. This is because this book takes place in a society where books are prohibited by a government that wants to completely dominate all factors of freedom, knowledge and individuality in society.
For this reason, we can say that the statement that firefighters are the "custodians of [society's] peace of mind, the focus of [the] understandable and rightful dread of being inferior," means that they have the ability to promote intransparence in relation to the sense of freedom and individuality.
This is quite difficult to answer since the puritans were persons who had very strict moral values and i can't find an answer to correspond with the definition.
