@SSS26032002
There's an entire subfield of linguistics (with tons of overlap between fields, really) called the "philosophy of language". This manga takes several related concepts, including psychological nativism, as well as the existence of universal grammar, as plain truths, and doesn't bother to question anything. If you felt some sort of discomfort as you were reading through that section, it's because your brain wasn't making sense of something that couldn't be falsified; the core logic behind the existence of words, and their ability to invoke powers/magic in this universe, is circular but also left as-is.
It might be wrong, or it might be right, but you can't prove it either way~