So much of the writing craft is about balance, how much to tell the reader. There are many aspects of this balance: how many hints, how deep the info--too much and you give away the surprise, or you kill your suspense. I have been struggling with this very issue in the sequel to Seaborn, but I'm thinking of another aspect of balance.
How much do you write for the present, an audience of today but not tomorrow? How much history, cultural depth do you--or should you--fill your pages with? It's a question for genre, historic, contemporary, all kinds of lit--even purely made up worlds. Although there are differences with the last because a reader cannot know your world without you. Unlike our world--this world--21st Century Earth--where I can have two characters talking about a tyrant's downfall and have one say, "He'll most likely end up like Hitler."--and leave it at that. I don't need to explain. There are facts a storyteller can assume a reader will know, but it is that assumption that is the balance we have to deal with: can you assume that all audiences will know? Is the best bet to pick your audience and write to their level of understanding--their current level of understanding at this point in time?
3 o'clock this morning, Antisthenes by way of Aristotle got me thinking about this, because Ari assumed his audience would always know certain facts. In the Politics [around 1284a] there's a great line that goes something like, "...it's like the response from the lions in the parable of Antisthenes when the hares came before the assembly demanding equality." That's it. Aristotle didn't think it necessary to include the lion's response--not when every freakin' kid in the agora knew. But 2400 years later, not every freakin' kid is familiar with Antisthenes' work.
I'm going to spend some thought on this because it's definitely worth keeping in mind when mentioning historic events, cultural references, popular works, Buffy, Harry, Scotty, Freddy, Elmo--will you're readers two millennia away understand you without footnotes? Do they need to? Do all writers write for a certain time, a century, an era, but no more--beyond which they need analysts and historians rooting through the news and Net garbage to find out what the hell you were talking about?
Oh yeah. The lions asked the hares, "Where are your claws and teeth?"