One of my favorite books to pick up and read random sections from is Shakespeare: The Invention of the Human by Harold Bloom. He means the title literally: "Our ideas as to what makes the self authentically human owe more to Shakespeare than ought to be possible." I don't know if I'd go that far, but no writer can deny the primacy of Shakespeare, and you ignore it at your peril.
In high school, everyone has to read Julius Caesar. It's a perfect introduction to Shakespeare: narratively it's a simple play, it has a speech second only to "To be or not to be..." in the public consciousness, and it features gang murder and ghosts. I remember reading it aloud in English class, and marveling at how the archaic-looking speech came to life when spoken. Then I got beat up for being a dweeb.
But Julius Caesar has a surprising timelessness. Consider the speeches of Brutus and Antony following the assassination of Caesar. Both face a crowd of panicky, easily-swayed citizens (described earlier as "you blocks, you stones, you worse than senseless things," almost as if they sat home every night watching The Hills and Dancing with the Stars) who demand an explanation.
Brutus speaks first. He is calm, rational, and he lays out the reasons for killing Caesar in a logical fashion. He appeals to the citizenry to judge his actions for themselves ("...censure me in your wisdom, and awake your senses, that you may the better judge."). And then, in one of the dumbest moves ever (right up there with "Put on those gloves, O.J."), he lets Caesar's friend and acolyte Mark Antony address the crowd.
(Marlon Brando as Mark Antony in 1953's Julius Caesar)
Antony, in observing the chaos when Caesar's death is leaked, makes a key observation: "Passion, I see, is catching." In his famous speech, he turns the crowd entirely against Brutus by appealing to their emotions, by producing bogus documents ("But here's a parchment with the seal of Caesar; I found it in his closet, 'tis his will.") and of course by claiming he isn't trying to do exactly what he's doing ("Good friends, sweet friends, let me not stir you up to such a sudden flood of mutiny."). The result is civil war.
Not to belabor the point, but Antony would fit right in with the calculating, maniacal voices on the Right screaming about socialism and Gomorrah with virtually no interest in actual facts; Brutus, while he does have the courage to get his own hands bloody, is as effective a public speaker as Al Gore on the campaign trail. And the Roman citizens, as already noted, are just as content to have their opinions handed to them as many of us are.
So what truths, ultimately, does the 400-year-old Julius Caesar have for teenage boys?
About their society: that in the war between passion and intellect, passion always wins, because most people would rather feel than think.
About Shakespeare: that Harold Bloom just might be right.