The rule of threes is a part of many artistic endeavors.

In a joke, the punchline always comes with the third example.

In popular music, like a Beatles tune, it’s the hook sung by Paul, the “middle eight” bars of the chorus sung by John, and a return to the hook, usually with Paul and John singing together.

And in screenwriting it’s Act One, Act Two, and Act Three, but what happens in Three must have what the joke or the pop tune has: synthesis.

While doing a evening presentation with a great group of writers at Disney Animation this week, I realized just how important that concept is.

You may call it Act One – Act Two – Act Three. I call it Thesis – Anti-thesis – Synthesis.

And this Hegelian triumverate is crucial to satsifying storytelling.

In Act One of Titanic for instance, the Thesis world is Rose (Kate Winslet) about to marry the wrong man.

In Act Two, the Anti-thesis, Rose falls for Jack Dawson (Leonardo diCaprio) and the “upside down version of the world” includes them exploring all levels of the ship and their future… up until both strike an iceberg.

In Act Three, with the ship sunk, and Leo dead, the lone survivor, Rose, is asked by officials for her name. “Rose Dawson” is her answer.

The perfect Synthesis beat!

Rose took what she was in Act One, combined it with what she learned in Act Two, to create a third way, a synthesis of the two!

And examples of these “Synthesis” moments are found in lots of Act Threes.

In 10, starring Dudley Moore, Act One is Dud in midlife crisis, with a girlfriend, Julie Andrews, he can’t commit to.

In Act Two, Dud chases Bo Derek, and learns from her the lovemaking magic of Ravel’s “Bolero.”

And in Act Three, Dudley comes home, his midlife crisis over, and guess what the last beat is? Dudley making love to Julie to the sounds of “Bolero.” He took what he started with in 1, combined it with what he learned in 2, and found a third way, a new way.

Dudley’s transformation is complete, and so is his story.

What other “Synthesis” moments can you think of from the current crop of movies? I know what it is in Little Miss Sunshine, do you?

You must find the Synthesis beat in your own stories too. Without it, it’s a less satisfying journey.

The Synthesis beat shows that we can all learn from our mistakes, no matter how embarrassing, and triumph in the end because of them.