Hirsch's central concern is that we all have the ability to communicate with each other. Due to the increasing complexity and specialization in today's society, Hirsch says, citizens need to have some common basis, some common vocabulary, through which they can communicate. He then focuses on the background knowledge which is required to form such a common basis. For Hirsch, such background knowledge is important because it facilitates communication. To select an example at random from Hirsch's list, two people cannot successfully use a reference to Little Big Horn in a conversation unless both of them are familiar with it.
Taken at this level, and assuming that communication about all subjects is equally important, it us understandable why Hirsch would attempt to create such lists. Even so, Hirsch's reasoning is faulty. He has misunderstood the role that background knowledge plays in communication. And he has failed to account for how people learn background knowledge in the first place.
Cultural Literacy and Schema Theory
Where am I in the content of the book?