What was Big Willy Shakes going for?
After the Ghost tells Hamlet that Claudius has murdered his father, Hamlet begins to plan his next steps. After all, revenge is a dish best served cold, so it's not like he can just bust into Claudius' bedroom and bump him off in the middle of the night. So in this scene he warns his friends that he will put on an "antic disposition"—i.e., pretend to be a madman.
But here's the thing. After a while, we're not all that sure Hamlet's pretending. Sure he says he's gonna fake it, but we have to remember that Hamlet's already suffering from what the Elizabethans would call "melancholy." And Elizabethan ideas about "madness" are unstable and they're different than modern notions of mental illness. In other words, being melancholy (à la Hamlet) was, to them, a form of madness. Hmmm.
This seems like a good time for a History Snack break. Here's something you might like to know: Shakespeare borrows the idea of feigned madness from one of the play's major sources, the story of Amleth, a legendary Danish tale that dates back to at least the 9th century, if not before then. In the source story, Amleth clearly pretends to be mad after his uncle kills his father and marries his mother, Gerutha. (Sounds familiar, doesn't it?)
In fact, faking madness to throw people off is one of the oldest tricks in the book. In Hamlet, Shakespeare takes it up a notch because he makes us ask: does Hamlet truly go "mad," or is the cuckoo-talk, like the play itself, all an act? And if madness is a form of theatricality (maybe with some "method" in it, as Polonius says)—does that mean that all actors are crazy?
Hey, wait a second. Could Shakespeare be making one big joke at his actors' expense here? In fact, the word antic means mad or bizarre, but it was used a lot in Shakespeare's day to mean a madcap in a drama of some kind (source). You might be more familiar with the word if we said antics as in "that's enough of your antics" or crazy-acting, ya clown.
Shakespeare uses the word antic to mean a mask someone wears in Romeo and Juliet, when Tybalt says that Romeo came to the party "cover'd with an antic face" (1.5.54). If we think about it in that way, maybe Shakespeare is having as much fun with this madness as he possibly can in the theater. Actors do put on masks or characters all the time, just like Hamlet is saying he will here.
One little phrase, so many meanings.