The first thing we should point out is that Arthur Schopenhauer's philosophy does not include a treatise on bending reality to your will by way of spirit fingers. Although, now that we think about it, he may be more widely read today if it did. Dude would have owned the bestseller list for the past one hundred years.
Okay, if spirit fingers don't figure into Schopenhauer's concept of the will, then what's at play here? To answer that, you'll need to dive into Schopenhauer's epic, two-volume work The World As Will and Representation. In case you don't have time to read a thousand-plus pages of German philosophy, here's the snack-sized version.
For Schopenhauer, the Will (with a capital W) provides the foundation for everything in the world. It's the mindless, irrational drive of desires and life. You're keenly aware of one example of the Will: your internal reality.
As Schopenhauer explains, you can only see the external representations of objects and people, but you're internally aware of your own desires, feelings, subjective thoughts, and so on. This is your Will, and if you have a Will, then it stands to reason that everyone, and everything, does as well.
It's not all great news, though. Schopenhauer argues that the Will is the cause of all our suffering. In a move jacked straight from the Buddha's playbook, Schopenhauer argues that only escape from this suffering is to limit one's desires (source).
The Will to Life
Now let's wrap back around to Life Is Beautiful. Here's how the concept of will is introduced in the film:
GUIDO: Were you sleeping?
FERRUCIO: Of course I was.
GUIDO: You fell asleep while talking to me! How did you do that?
FERRUCIO: Schopenhauer says that with willpower, you can do anything. "I am what I want to be." Right now I want to sleep, so I was saying to myself, "I'm sleeping, sleeping," and I fell asleep.
GUIDO: Amazing. And it's simple. I want to try, too. I'm sleeping, sleeping, sleeping—
Life Is Beautiful is borrowing a few key concepts from Schopenhauer. The idea of an internal will that can be focused to produce results is one. In this scene, Ferruccio's focusing his internal desires to just one, sleep. And so, he sleeps.
Like Ferruccio, Guido limits his desires to focus on one or two things that he really wants in life. In the first half of the film, that thing is Dora's love, and we see him use the will to draw Dora's attention to him in the theater. In the second half of the film, it's keeping Joshua safe, and we again see him use the will, this time to draw a guard dog away from Joshua's hiding spot.
We shouldn't dig too deep into comparing Life Is Beautiful's concept of will with Schopenhauer's Will. The movie isn't trying to provide a thorough analysis of the philosophy, but more just borrowing a few key points.
Lucky for us, because becoming a philosopher wasn't on our to-do list today.