Apollonian and Dionysian Themes

I recently finished reading Stephen King’s Danse Macabre. It’s like the earlier version of his book On Writing except it’s centered on the horror genre: film, TV, books, etc. Throughout Danse Macabre, he discusses Apollonian and Dionysian themes, but what are they?

The Apollonian and Dionysian is a philosophical and literary concept based on parts of ancient Greek mythology. Apollo and Dionysus were sons of Zeus. Apollo was the god of the Sun, light and music. Dionysus was the god of wine, intoxication and ecstasy. In literary terms, Apollonian is the order, while Dionysian is the chaos.

For example, the film The Exorcist begins with a mother and daughter living the suburbs. You see a very order lifestyle where everything makes sense (Apollonian). The moment when you hear the animal-like roar order transitions in to chaos. Sweet Regan was taken over by something darker and Father Karras and Father Merrin come to her rescue, performing the exorcism (Dionysian). You don’t see order come back in to play until the end when you know the beast has been defeated and a drained Regan is placed in the back of a car.

Now it’s your turn. What are the Apollonian and Dionysian themes of Richard Matheson’s I Am Legend?