Another thought struck me recently regarding Shakespeare's use of poetry (and I'm not referring to the verse only; even his prose is poetic). As we listen, we are very much aware that people don't speak in those ways - this was one of Tolstoy's beefs about Shakespeare, in fact - but we're also aware that people do feel in those ways. And like with music or dance, we know that we're witnessing an exaggeration, but what this exaggeration leads to is of such depth that it's unlikely that it could have been found otherwise. The poetry, therefore, helps us to think certainly, but just as importantly, it allows us to empathize emotionally.

Also, the poetic language makes us immediately aware that we're watching fiction (even when historical sources have been consulted), but the quick establishment of this fact permits the mind to go past the surface issues of story-telling and veracity to get to the real psychological and philosophical content. For an example, here's Cassius speaking to Casca (1.3) about the reasons for Caesar's ascension; in his opinion, it's merely a symptom of Rome's weakness. Note the poetic content of the words and the emotions they release. Then imagine the danger in even thinking them:

And why should Caesar be a tyrant then?

Poor man! I know he would not be a wolf,

But that he sees the Romans are but sheep:

He were no lion, were not Romans hinds.

Those that with haste will make a mighty fire

Begin it with weak straws: what trash is Rome,

What rubbish and what offal, when it serves

For the base matter to illuminate

So vile a thing as Caesar! But, O grief,

Where hast thou led me? I perhaps speak this

Before a willing bondman; then I know

My answer must be made. But I am arm'd,

And dangers are to me indifferent.

Shakespeare's political sophistication seems boundless. In Julius Caesar, for example, he delineates the endless cycle toward, and then away from, centralized power. He embodies it in the character of Cassius, a man who knows enough of both Rome and himself to make his cynicism work for political ends, but who can't overcome his distrust of his own nature. He understands the dangers presented by Mark Antony much more clearly than Brutus does, but he lets himself be over-ruled in the play's moment of crisis: the decision of whether to allow Mark Antony to speak at Caesar's funeral. And we are introduced to this double nature the first time we meet him. At the end of 1.2, after his having convinced Brutus to at least consider joining the plot to assassinate Caesar, he has a moment of astonishing honesty in a brief soliloquy at the end of the scene. In it, he imagines telling Brutus the truth: that an honest man should avoid people like him (Cassius, that is), and that if he were loved by Caesar the way that Brutus is, that he wouldn't allow himself to be talked into upsetting his favoured position by anyone:

Well, Brutus, thou art noble; yet, I see,

Thy honourable metal may be wrought

From that it is disposed: therefore it is meet

That noble minds keep ever with their likes;

For who so firm that cannot be seduced?

Caesar doth bear me hard; but he loves Brutus:

If I were Brutus now and he were Cassius,

He should not humour me.