How did Finn think the Force would work?

Question

In The Force Awakens, the following conversation takes place, on Starkiller Base:

Han Solo: People are counting on us. The galaxy is counting on us.

Finn: Solo, we'll figure it out. We'll use the Force.

Han Solo: That's not how the Force works!

Finn was willing to lead Han and Chewie behind the enemy lines, without really knowing what he was about going to do. At the site, he figured they'd use the Force – of which he was never even supposed to have heard of! Where did he get the idea the Force would help them? And in what way? As a Stormtrooper of the First Order, where did he get any thoughts regarding to the Force, and how it works?

Answer 1

I'm going to take a dip into speculation, as neither Canon nor Legends really talks about any of this.

Where did Finn get any thoughts regarding the Force?

Stories, bar room chat, barracks yarns. Stormtroopers are obviously humans; conditioned humans, but humans nonetheless. They talk about landspeeders on screen in the movies; they obviously talk.

The biggest event in the universe? The toppling of the Empire by the "New Republic." And those conversations would have to include discussions about the main figures; Darth Vader, Palpatine, Luke Skywalker, Han Solo. Stories would trickle down about Vader throwing people across rooms, Palpatine predicting the future, and Skywalker beating them BOTH.

"The Force" would be something very powerful people used during the fall of the Empire, and he'd have heard about a guy named Solo being around all these "Force" people.

Where did he get the idea the Force would help them? And in what way?

I'm not a Muslim, but I have some vague ideas of what the Muslim faith might include, much of which is probably incorrect. Finn's in the same situation. The Jedi and the Sith are complex religious orders centered around superhumans with superpowers. He'd have scraps of data to work off of, but nothing solid.

Finn would expect "the Force" to help them, because he had Han Solo, and Han Solo had been involved in the toppling of the empire, where "the Force" was claimed (at least by New Republic propaganda) to have been involved in the event.

Remember, Finn is a Stormtrooper. He knows what a bunker on Endor would be like. He knows how big and powerful a legion of troopers is. He is fully indoctrinated in the concepts of the Empire as a neigh-invincible behemoth against which none can stand. And he knows it LOST, against something that claimed to have "the Force." This would awe Finn; "the Force" must be powerful indeed!

So Finn thought of the Force as just some magical "something" that made battles easier for believers. It was "something" which allowed you to blow up two Death Stars and destroy millions of Imperial Troops and trillions of credits worth of Imperial Hardware. He didn't know how it worked, but he was sure it DID work, and that Solo could do something with it.

Answer 2

Finn had previously witnessed Kylo Ren stop a blaster bolt in mid-shot and then hold it as he continued on a conversation/interrogation.

Also, he is shown to be acutely aware that Kylo Ren was aware of him and his conscientious objection to firing on innocents, an event he did not witness yet still managed to sense.

He obviously has witnessed demonstrations of the power of the force, moreso than probably most of the other sentients in the galaxy in this era (50+ years after any casual, open use of the Force apart from the occasional asphyxiation on the bridge of a star destroyer..)

Finn has direct first-hand experience with both the powerful, physical manifestations of the force, and the more subtle, unnerving psychological aspects of it. Defying the physical laws of the universe and reading minds, looking into his soul? In the eyes of a young grunt - what can the Force not do?!

As an aside, I hope I did well for my First answer ever in this site. Please correct Me if I need to change anything to make My answer work