I came home yesterday to find a foam sword and a blue plastic squirt gun on the patio. It was a hot summer day, and obviously the kids had been having a rousing game in the backyard. But still, the sight of a gun and a sword on my back step chilled me.

The Aurora shootings were instantly on my mind. I'm a mom. But I'm also the author of a parenting book; one that actively supports weapon and guy play for young kids. Where does that put my thoughts now?

Exactly where they were before. Supporting free play ideas for kids -- even when that includes weapon play. Here's why.

• Good guy/bad guy play is about morality. War play is sometimes called "mythic play." Whether it's monsters, cops and robbers, Star Wars or Harry Potter, kids are playing out age-old themes of good and evil, life and death, power and protection. Exploring what's right and wrong, good and bad, is fundamental to developing morality. That's something we want to encourage.
• Weapon play is often about saving people. War play puts kids in the position of being the hero, the rescuer. "I'll save you!" they shout. Whether the game is firefighter, knight or space bomber, kids are often trying on the role of hero.
• Empathy emerges in curious ways. A key part of learning empathy is to see things from another perspective. When kids say "I'm Darth Vader, " they're trying out different roles. That's great for developing empathy.
• Pirate hats don't turn kids into pirates. When children play pirate we understand it's pretend play. We don't worry our child will grow up to be a pirate. Real-life pirates are thieves and murderers, but kids playing pirate are having fun and seeking action and adventure.
• Play helps kids combat fears. Kids suffer from intense fears. Fears like clowns, dogs, thunderstorms, monsters, the dark or a new baby. Carrying a foam sword or plastic gun helps some children slay their inner fears and makes them feel safe.
• Kids need props for play. That's why kids grab a stick or wave a banana to make impromptu weapons. One boy whose mom banned gun play wielded a toilet plunger. Props like dolls, trucks and toy weapons are important. All kids, but boys especially, need to manipulate objects in space. It's how the human brain is wired.
• Behavior in real life is what counts. Are kids having fun? Treating other kids well? Do they stop and become concerned when someone gets hurt? Actual behavior counts. Tell kids "people are not for hurting" and set limits to enforce it.
• Play ideas are part of the child. When we censor play or change a play idea ("that's not a gun, that's a magic wand"), kids think their ideas are bad. "Guns are bad. I like gun play. I guess I'm bad." Kids have a right to explore their interests, and forbidding weapon play doesn't stop a child's interest in it. They'll simply pursue their interests behind our backs -- and that's particularly troubling when it comes to gun play.