At this point it’s the conventional wisdom: Marvel did in a few minutes of Captain America: Civil War screentime what Sony couldn’t do in five films - create the definitive, comics-accurate Spider-Man. But even as everyone basks in the glow of the real Peter Parker on screen, there’s been a subtle chorus of people complaining that Spidey is shoe-horned into Civil War, that his appearance is just an ad for next year’s Spider-Man: Homecoming. And if you’re going only by plot, these people may have a point - Spider-Man could be excised from the plot mechanics of Civil War without making too much of a difference (maybe the airport fight goes differently?). But what makes Civil War a great movie is that it is more than a plot - it’s a film with rich themes and complicated character arcs, and Spidey services both of those things.

When Peter Parker is first introduced (I love the update to his life, by the way. In the 60s it made sense that the Parkers would live in a little house in Forest Hills, but in the 2010s an apartment is the only way to go. And is that the same apartment complex where the finale of Iron Man 2 happened?) the audience goes nuts. The second ‘QUEENS’ flashes on screen people know what they’re in for. And those first few minutes - Tony bantering with an unusually attractive Aunt May, Peter trying to figure out if there’s money in it for him, the revelation of the Spider-Man YouTube videos - are great. Fun and funny.

Then you begin to get this sense of “What is this even doing in the movie?” As Tony works to recruit Peter the film feels dangerously unbalanced, as if it’s about to spin out of control in the service of setting up future films (is that the same problem from the first two acts of Iron Man 2?). But just as everything gets wobbly and just as it looks like Civil War will succumb to shared universe overload, Peter gives a little speech and everything snaps into place.

It’s a new version of the classic “With great power comes great responsibility” speech that guides Spider-Man’s entire heroic career. It’s similar to what Uncle Ben famously told young Peter, but it’s been modified, refitted so that it drops like a bomb right into the middle of this movie. Spider-Man says these words and he recenters the entire ideological battle at the heart of Civil War:

"When you can do the things I can do, and you don't, and then the bad things happen, they happen because of you."

It’s a really important moment, and the Russo Brothers play off Tony’s face for a quick beat. What’s happening here is that Peter is, quickly and succinctly, using Captain America’s logic. An Avengers whose hands are tied behind their backs due to bureaucratic regulation would be an Avengers who are complicit in the bad things happening in the world they aren’t allowed to stop.

This beat is vital because it’s a moment on Tony’s journey towards helping Cap at the end. Peter doesn’t really know what he’s signing up for - he’s just there to help the famous and smart Tony Stark - but it’s clear that if he were presented with the full ideological argument he would side with Cap. And his personal mantra - the idea of great power bringing great personal responsibility - does sink in with Tony here.

Not enough, of course. And neither does Peter’s age. This is one of the elements of the film that I suspect may play too subtly (partially because we just want Spider-Man in the film kicking ass), but Tony Stark is completely wrong to recruit Peter Parker.

It’s pretty likely that he showed up at the Parker apartment unsure of what he was going to find. Tony’s initial interest in the Spiderling was his webs - he wants Spider-Man on his team as a non-lethal solution to the conflict. Those webs can easily and quickly take Cap and friends out of commission. He doesn’t know whether Peter is organically generating the webs or what, and by the time he realizes that Pete has created his own web shooters, Tony is already well on his way to recruiting the kid, not even considering that he could just get the tech.

This is Tony making a mistake. It’s one of the defining aspects of Tony Stark in the movies - he makes big decisions on the fly and they are quite often either wrong or incredibly destructive, and here he’s making another one. Thankfully it’s not apocalyptic - this isn’t another Ultron moment - but it’s a vital moment in his character arc and a chink in his ideological armor.

Remember, all of this begins with Alfre Woodard at MIT, showing Tony a picture of her dead son - a son who is even older than Peter Parker. It’s the death of this innocent that starts Stark on a path towards the airport battle, one where he has no compunction against bringing another young innocent into harm’s way. Tony hasn’t learned a lesson, he’s just feeling crushed by personal guilt. The fact that he recruits 15 year old Peter Parker to fight Captain America only proves that Tony Stark is looking at the Sokovia Accords as a way of taking responsibility and guilt from his own shoulders. He's cutting the wire, not laying himself down on it, to go back to Tony and Cap's first argument way back in The Avengers. He's not interested in taking responsibility. He wants to shrug it off onto someone else.

This is vital for the balance of the film. Cap’s position is a little more vague than Tony’s - he’s arguing for larger concepts of freedom while Tony is arguing for nuts and bolts regulations that answer specific incidents and problems. Logically it’s hard to fault where Tony Stark is coming from, and emotionally it’s easier to be on Cap’s side (he’s trying to protect his best friend). By having Tony make this mistake the film undercuts his own position, bringing the two sides into closer balance in our minds. And that balance, I believe, is everything for this film - you should be able to argue passionately (and correctly) in favor of both Team Cap and Team Stark.

Besides the thematic and character aspects of Spider-Man’s introduction into Civil War, it happens at the exact right moment structurally. After all that has happened in the movie we need the reminder of just what this is all about. Peter’s little speech is vital for his character - it’s a clever way of summing up his origin - but it also recenters the film at a moment when it is most needed. Just before the two teams meet on the tarmac for the greatest superhero brawl yet put to film, the script reminds us why these friends are even at odds in the first place.

You could pull Spider-Man out of Civil War and have the same basic plot, but the plot isn’t the be-all, end-all of a movie. Spider-Man’s role is fundamental for the film’s larger thematic concerns, and I don’t even know what the version of this script was like before Marvel and Sony reached their deal.

Oh, and he’s also cool as hell. Sometimes that alone makes a character or a scene indispensable. Let's not pretend we're above wanting cool shit in our movies.