Symbolism, Imagery, Allegory
Science is all about facts, right? About cut and dry provable truths and all that concrete jazz… Except in this book, that is. Instead, in Here Be Monsters!, science represents the double-sidedness of everything in life. This is because this book doesn't care so much about science itself as what it gets used for. And in its use, we see science do good things, bad things, and in-between things, too. If you've heard the idea that any tool, wielded a certain way, can become a weapon, that's what we're talking about here.
Marjorie's invention exemplifies this. She created the resizing machine out of pure curiosity, saying:
"I was very interested in the scientific principles involved in making it. I just wanted to see if it would work. I hadn't really worked out what it was going to be used for." (31.53)
Her intentions are good enough, but then the Trouts steal her invention and hand it over to Snatcher, who most definitely uses it for evil. The technology itself is neither good nor bad in its own right—it's the using it that makes it fall to one side or the other.
By contrast, Snatcher's been using a big old magnet to keep Herbert powerless in his cell. Once activated, the magnet grips his iron socks and doesn't let him swing at his captors with his walloper. But when Arthur and his buddies are trying to stop Snatcher, Framley, and the rest of the minions from destroying the town, they repurpose the magnet to get it to drag all the weapons and Framley's armor back to the Cheese Hall. Pretty nifty, huh?
From these scientific inventions, we see that technology itself is neutral, neither good nor bad. Instead it's how people utilize technology that opens up a bunch of possibilities. So keep on eye on the relationships characters have with inventions and innovations in this book for clues about, well, their character.