Be warned, if you have not seen Man of Steel yet, there will be HUGE spoilers throughout the rest of this article.

One of the more polarizing moments of this summer's blockbuster Man of Steel is when Henry Cavill's Superman kills Michael Shannon's General Zod. Screenwriter David S. Goyer defended the controversial moment, which ran in stark contrast to the comic books where Superman is always reluctant to take another life.

Take a look at what the writer had to say, while delivering a lecture for BAFTA and BFI.

"We were pretty sure that was going to be controversial. It's not like we were deluding ourselves, and we weren't just doing it to be cool. We felt, in the case of Zod, we wanted to put the character in an impossible situation and make an impossible choice.

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This is one area, and I've written comic books as well and this is where I disagree with some of my fellow comic book writers - 'Superman doesn't kill'. It's a rule that exists outside of the narrative and I just don't believe in rules like that. I believe when you're writing film or television, you can't rely on a crutch or rule that exists outside of the narrative of the film.

So the situation was, Zod says 'I'm not going to stop until you kill me or I kill you.' The reality is no prison on the planet could hold him and in our film Superman can't fly to the moon, and we didn't want to come up with that crutch.

Also our movie was in a way Superman Begins, he's not really Superman until the end of the film. We wanted him to have had that experience of having taken a life and carry that through onto the next films. Because he's Superman and because people idolize him he will have to hold himself to a higher standard."

At the same event, the writer was also asked whether or not he is writing Justice League movie for Warner Bros., although he would not give a concrete answer.

"Might be, can't say."

Will Beall wrote the screenplay for Justice League, but the project does not have a director attached at this time. Warner Bros. announced at Comic-Con 2013 that Justice League is in development for a 2016 release date.