Ha ha ha, OP you are completely right! And yet I still like the film! I forgave the insane weakness of the aliens by the great suspense and set up of the movie. But yeah, seriously, water?
The problem with a motif mashup is that it confuses the audience. As you say, the aliens behave very much like bogeymen, but that doesn’t make defeating them in a fairy-tale manner effective drama, any more than feeding Jaws garlic would be.
I agree it’s not central to the theme of the film, so it’s not a fatal flaw, but that’s a poor argument. By that token, having the family join hands in prayer and be saved by the mother’s ghost shooting laser beams from her eyes would be a satisfying resolution. I’ll also have you know there is nothing wrong with my imagination. I can picture up to three naked ladies in my head at once (any more than that, and it gets difficult to keep track of which bits belong to whom).
Funnily enough, it’s quite possible that our environment might be poisonous to extraterrestrial life, and vice versa. Many elements are toxic to us in small does. Life that evolved elsewhere might be much less tolerant to them, as they exist in lower abundances on their world. We might have the same problem on an alien planet, even if it had a breathable atmosphere. In astronomical terms, some star systems have a higher metallicity (elements heavier than helium) than others. Also, geological processes can concentrate some elements on the surface and deplete others.
Very satisfying, if you ask me. Is it too late to demand a rewrite?
What, you think I’m on speaking terms with Mr Shyamalan after writing that OP? 
I’m not a hater of his work btw. I enjoyed The Sixth Sense, and didn’t see the twist coming. I also thought Unbreakable and The Village were decent enough.
Yes, it does kind of slap your suspension of disbelief right in the face. Of course, plenty of other science fiction/monster movies deal with their bogey-men in a similar fashion, except the cure is some technobabble subsonic emitter or radio whosis or fire extinguishers or crucibles of molten metal. So when it turns out that you defeat the aliens by clicking your heels three times and saying “there’s no place like home”, or melting them by splashing them with a bucket of water, it makes perfect sense dramatically–they kick our ass until we find the lucky feather, and then we kick their ass.
So in a twisted way I kind of respect Shamalyan for stripping the motif down in the starkest possible terms–It’s the old “What’s that, magic potion? Good thought so. What do we do, drink it? Good, thought so.” No need to worry about exactly how your magic feather works. Except it causes a bit of whiplash when cure turns out to be the bucket of water that melted the Wicked Witch of the West. On the one hand, of course we’ve been watching a fairy-tale from the beginning. On the other hand, you just melted aliens with a glass of water.
As I’ve remarked i a previous thread on ythis, it’s explicable and understandable if the object of the aliens is really to unload their excess population by having the alien leaders telling the poor slobs sent down that they’re the vanguard of an invasion force.
As I’ve said in previous threads, the fact that the characters ASSUME the beings are aliens does not necessarily make them aliens. We see lots of UFO tropes, but at no point do we actually see a spaceship or anything of that nature. The monsters could just as well be demons, or fairies, or the Silence or something else that’s been there all along.
In light of this, my opinion is that complaining that “aliens came all the way here and didn’t protect themselves from water” are missing the point.
Eh, I enjoyed it.
So instead of “came all the way here and didn’t protect themselves from water,” it’s “been here all along and still don’t protect themselves from water.”
I actually liked that movie, even with Mad Mel on board. With the exception of The Village, which *still *had some good stuff in it, I like Shymalan’s work in general.
The man can tell a story, which is why I have all of his films - yes, even ‘Lady in the Water’ on DVD. 
It’s not even about the water though! They were just terrible villains. If you can kill something by smashing a glass of water at it with a baseball bat, then you can kill it better with a shotgun. The entire plot hinged on this Bond villainesque method of killing the aliens when bullets would have been more effective, because they also had no defense against getting ripped to shreds with hot lead.
Surely not shudder The Happening too?
I.
DON’T.
CARE.
I lovelovelovelovelove this movie. It has a simplicity about it. And the little girl is so scrumptiously adorable (and I’m not a great kid-lover) I want to adopt her tomorrow.
So they were the “B Ark”? You lot go down to Earth and get things started. We’ll come and join you real soon. (“Thus ridding themselves of the entire useless third of their population.”) That could work.
[QUOTE=CalMeacham]
As I’ve remarked i a previous thread on ythis, it’s explicable and understandable if the object of the aliens is really to unload their excess population by having the alien leaders telling the poor slobs sent down that they’re the vanguard of an invasion force.
[/QUOTE]
Oh I love you both! It’s the best explanation.
Actually the idea that they were aliens smart enough to cross the distances of space but not smart enough to know water would kill them (or how to get through pantry doors) is completely believable to me. If we humans someday figure out how to get to another planet I would be completely unsurprised if we failed to pick out the thing in the new environment that would kill us quickly.
I love this movie. I love the atmosphere, the tension, the relationships. As a movie about aliens its pretty silly (but so are most movies about aliens). As a movie about faith it is pretty stupid. I loved the movie but I hated the last scene (Gibson puts on his vestments signalling his faith is restored). **Alka Seltzer **your OP is very funny and points out everything that is wrong with the faith message of the movie, but you can’t make me not love it.
Hey, did anybody but me notice that the whole terrible “everything happens for a reason” theme was plucked from A Prayer For Owen Meany? That’s why there’s a baseball bat and a dead mother.
I saw it as that too but even after taking that into consideration, I still found that the aliens’ vulnerability to water was such a lame plot twist that it undermined the entire film. Basically, it’s about 2/3 of a good movie. However, after you see the videotape of the aliens at the birthday party, it (and, in retrospect, the quality of Shamalyan’s movies since then) goes downhill rapidly.
Anyway, since we’ve brought up the subject of Signs being a parable about faith, I remember on another website (the now-closed Fametracker’s), there was the explanation advanced that with the exception of the very last scene, the whole movie is Gibson’s character’s dream. The aliens’ weaksauce weakness to water and their apparent inability to open doors were cited as the main proof of this since these would be the types of things that would only make sense in the context of a dream. As further proof, there were also the several surreal scenes featuring strange conversations like the one with the military recruiter (which looked like it came from a David Lynch movie). This wasn’t my theory, BTW, but it did seem to get a surprising amount of traction at Fametracker. Of course, it could’ve been a rationalization since nobody at that time would believe a talented filmmaker like Shamalyan would use a pathetic half-assed twist like the aliens being defeated by water without it being a dream of some sort.
Then the whole population was killed by telephones that kept collecting moisture and dripping into their mouth-holes.