Avengers: Endgame closed the door on the 22-movie Infinity Saga with massive amounts of payoff for fans (which, judging by the box office, is providing massive payoff for Marvel, too). The film also gave us the final live-action cameo of Stan Lee, filmed before his death at age 95 in December.

While the scene was anticipated by anyone familiar with the MCU, the final Lee cameo is also a thumb in the eye to anyone who thinks that putting politics in comics is a modern age development.

[Ed. note: This piece contains spoilers for Avengers: Endgame.]

Thanks to the magic of special effects, and the fact that we have access to photographs of Lee from the 1970s, the Endgame cameo features a younger version of Stan driving by Camp Lehigh in Wheaton, New Jersey, shouting, “Make love, not war!”

Directors Anthony and Joe Russo have said that Stan was not playing himself in his Endgame cameo, but rather a nameless hippie character. But it’s significant to note that shouting such a thing would not be out of character for Lee. The protest is a sentiment he shared to a large degree; Lee wasn’t shy about showing social justice values in his comics.

No was he a stranger to war. During World War II, he enlisted in the army and served in the Signal Corps before being transferred to an office role where he wrote military posters, fliers, and propaganda. The job saw him working alongside such later known greats as director Frank Capra and writer-illustrator Theodor Geisel (Dr. Seuss).

But he also later lamented his initial naivety about warfare, having romanticized it. In an interview with Web of Stories, he explained, “World War II broke out and, like an idiot, I volunteered. I wanted to be a hero.”

While Lee joked that Nazis provided great villains for comic books, he found nothing funny about real life Nazis or actual warfare. As a Jewish man who grew up in New York City during the Depression, he had experienced prejudice and seen violence and bigotry around him, and World War II showed him more of the same. He appreciated the troops on the ground and believed that evil needed to be stopped. But in interviews and panels over the years, Lee was clear that he considered war a terrible thing that robbed the world of good people who might otherwise have improved it.

Lee hoped that more people would put their efforts into love, art, scientific development, and discovery rather than warfare. You can see that in his stories and heroes he co-created with Jack Kirby, Steve Ditko, Larry Lieber, Don Heck, and others. In the original Fantastic Four comics, Reed Richards and Ben Grimm are both World War II vets who gain superpowers and immediately decide not to be warriors, but rather explorers and protectors. Spider-Man is constantly bullied at school, but keeps himself in check and ignores the insults because unleashing his strength in anger could kill someone. With great power comes great responsibility.

Tony Stark is a weapons developer who becomes Iron Man as a result of having to, for the first time, put his brilliance towards saving lives rather than taking them. In Lee and Kirby’s origin for Thor, the god of thunder has his divine power removed as punishment, after he deliberately seeks out war and violence just to show off his strength. Thor learns his lesson, but afterward must maintain his newfound morality and humility to be worthy of his power, or it will leave him again.

To talk about social justice through their heroes, Lee and Kirby brought Hitler back to life as Hate-Monger, now wearing a KKK-style costume while encouraging class and race warfare in America. When Kirby later created the Silver Surfer, Lee used the character as a type of lost philosopher who could voice some of the writer’s deepest ideals and fears.

In the mini-series The Silver Surfer: Parable, the Surfer speaks against warfare and hatred, asking, “If life is the most precious gift of all, then is not its loss a matter of monumental consequence?”

During the 1950s, ’60s, and ’70s, Lee visited college campuses to talk about the moral values that made tales of heroes and superheroes timeless. He argued against comic book critic Dr. Frederic Wertham’s claims that superheroes represented fascist ideology, saying that a fascist wants to dominate, while the superhero uses violence as a last resort to protect others.

When Lee stepped back from writing comics, he still kept his voice in the world of Marvel in the role of editor, approving and influencing new stories about social justice and political corruption. He also spoke directly to Marvel readers through his column, Stan’s Soapbox, which appeared in every Marvel Comic for decades. In the Soapbox, Stan spoke his hopes that the troops in Vietnam would come home safely and as soon as possible, and in 1968, he used the Soapbox to talk about bigotry.

Let’s lay it right on the line. Bigotry and racism are among the deadliest social ills plaguing the world today […] The only way to destroy them is to expose them — to reveal them for the insidious evils they really are. The bigot is an unreasoning hater […] it’s totally irrational, patently insane to condemn an entire race — to despise an entire nation — to vilify an entire religion. Sooner or later, we must learn to judge each other on our own merits. Sooner or later, if man is ever to be worthy of his destiny, we must fill our hearts with tolerance. For then, and only then, will we be truly worthy of the concept that man was created in the image of God — a God who calls us ALL — His children.

Some readers at the time criticized Stan and Marvel for pushing social justice agendas or political viewpoints in comics. Stan had an answer for that in a 1970 Soapbox column.

From time to time we receive letters from readers who wonder why there’s so much moralizing in our mags. They take great pains to point out that comics are supposed to be escapist reading, and nothing more. But somehow, I can’t see it that way. It seems to me that a story without a message, however subliminal, is like a man without a soul […] None of us lives in a vacuum — none of us is untouched by the everyday events about us — events which shape our stories just as they shape our lives. Sure, our tales can be called escapist — but just because something’s for fun, doesn’t mean we have to blanket our brains while we read it!

Lee maintained these views into his later years. He spoke out against white supremacist marchers in Charlottesville, VA. He criticized people who saw glory in warfare and strength in hatred. In an interview with the website Cyberspacers, he said, “Those in this world of ours who are not the heroes, and who in fact may be the villains, are the ones who always follow the easy path. They are the ones who do not care about others.”

In a 2016 interview with the Huffington Post, Lee was asked about how some people today still resist inclusivity in comics, TV and film. He responded:

”A lot of people are just too narrow-minded and a little bit bigoted. And there are a lot of people who feel that if somebody is not just like me, he’s a bad guy … And if my books and my stories can change that, can make people realize that everybody should be equal, and treated that way, then I think it would be a better world.”

It’s fitting then that his final appearance in the Marvel Cinematic Universe featured him declaring, “Make love, not war.” More fitting still is that as he said this, he drove a car with a bumper sticker featuring one of his most famous catchphrases: “‘Nuff said!”