I'm not sure it's so cut-and-dry. Non-magical though squibs may be, Filch was able to see and interact with the Hogwarts castle. From what I remember, Hogwarts appears to muggles as an ancient ruin and not an inhabited castle. Obviously that's not conclusive (there are tons of outs that could work; Filch may have a particularized exception to those anti-muggle protections for his position, the protections may be based on whether the subject knows of the existence of magic, etc.) but it supports a non-cultural separation between the muggle and squib categories.

 

1. The Grangers were able to walk around Diagon Alley just fine, after they had been led past the Muggle-repelling boundary. Do we ever see Filch enter the castle under his own power? Mere presence inside the castle isn't enough to show that he's immune to the Muggle-repelling charms, just as the Grangers being inside Diagon Alley doesn't show that they somehow have immunity.

2. Even if squibs can get past Muggle-repelling charms, it doesn't necessarily imply that there's anything magically different between Squibs and Muggles. Magic can target cultural distinctions just fine (i.e. job positions). Prima facie, a Muggle repelling charm would not repel a squib because they're not considered Muggles, even though they're physically and magically identical to Muggles. The magic is targeted at the socio-linguistic category of "Muggle", not the biological/physical arrangement of the being.

JKR said squibs don't have magic in the same way Muggles don't have magic, so that's the default position. It could be displaced by something from the books contradicting it, but I don't think there's anything in the books which forces you to discard JKR's statement.

 

I'm not arguing that there is a magical difference between squibs and muggles, only a non-cultural one. I would certainly state that the two options presented by you were also included in my 'easy outs' catch-all and that it would not be unreasonable to read the text as supporting a non-cultural difference between squibs and muggles.

Nonetheless, even if you include what I'd consider non-binding dicta, I still believe that there is sufficient evidence that a non-magical, non-cultural difference exists between squibs and muggles. For instance, we know from one of Rowling's Bloomsbury chats that muggleborns are descendant from a wizard somewhere deep in their ancestry (logically this means a squib would also be in a muggleborn's ancestry). In particular, she uses the word "gene" to describe this process which certainly suggests to me a physical difference.

As an aside, I feel like that was almost certainly an error on the part of Rowling's general scientific and mathematical illiteracy. It tends to undermine her overall inclusive, anti-bigotry message. Further, if magic is genetic it would tend to make magic more 'scientific' which is a road I'd rather not travel down.

Also: Aleister Crowley seems like a reasonably eccentric 'real' person to have been a squib. For a more contemporary but similar situation: comics writer Alan Moore would also make a good candidate (though, honestly, he could just be a wizard masquerading as a muggle).

 

He's not even hiding it.

 

Aleister Crowley? Squib? Haha. That's a good one. It actually made me laugh. I didn't expect many people here to know about him. But yeah, you are probably right. That also suggests that magic isn't biological, since Crowley believed souls exist. But then again, I am more of a opinion that Crowley was more likely just "a wizard masquerading as a muggle," as redlibertyx put it, considering sheer number of books and essays he wrote about his "magick".

 

Leonardo da Vinci was a wizard who dabbled in necromancy and invented the magical portraits.

 

I'm gonna be that guy.

J.K. Rowling.

 

Alternatively, you could make it so that some wizards believe that great muggles were squibs or wizards. Someone mentioned Sherlock Holmes earlier so as an example you could put a wizard mentioning how Sherlock Holmes was actually a wizard in disguise before someone points out that he is a fictional character.

That said... Chris Angel. Even if he is actually a muggle it would be amusing to see a wizard seeing a show and thinking he is breaking the Statute of Secrecy.

 

I could kind of see Lovecraft as a squib who saw or was near a Dementor as a child, and used the experience to fuel his writing later on.

Can Squibs see Dementors? Having no magic of their own I would think not, but I'm not sure if it stated whether or not Filch was able to see them in 3rd year.

 

Well, Figg couldn't actually see them, she just knew enough about them to convince the court they were there.

 

I cant recall wasnt it mentioned Muggles cant see Hogwarts but somehow Filch can see Hogwarts? Or is it a notice-me-not charm?

 

What it is actually called, is a plothole.

 

I talked a but about this above:

Worth remembering that "notice me not charm" is fanon. In canon the effect of diverting attention from something appears to be achieved by a variety of different spells.

 

Maybe it works similarly to the Fidelius - only people who actually know about the Magical world, including Muggles who were explicitly told about it, can see and enter these places.

 

That would make for an interesting premise. Wizarding Worldis hidden behind a Fidelius Charm that was applied at the point the Statute of Secrecy was signed and the secret disseminated to all the witches and wizards in the world (obvious exceptions apply). Since the secret keeper is long dead by this point, everyone who holds the secret is, in part, the secret keeper of Wizarding Britain.

The Hogwarts letter everyone receives would then be the method of passing on the secret to muggleborns and half bloods that don't know it already.