Hermione and the Lack of Logic

[conuly]

I know everybody thinks Hermione is oh-so-smart, but she really *is* illogical. Think of how she acts to Luna! Just because there's no proof of nargles means they don't exist? Does she hear herself? There are people in the world who would say that witches don't exist, but Hermione's very existence (such as it is) is proof against that!

So here's the question. How has Hermione gone so long without learning that a lack of proof for something (say, nargles) isn't the same as proof against something? People didn't believe until giant squid until very recently, and yet they still exist.

That was short. Sorry.