On the other hand, Bacon’s diary has nothing to commend it in terms of material (it is just a book),
I’m not arguing, but how do we know that? IIRC we’ve never seen exactly what was in there, and Harry never got around to reading it. And it doesn’t sound like Quirrell to just make a gift just because it’s an “old rare item”, especially since he doesn’t quite like science and Bacon’s relevance to Harry is not that he had magic, but that he was a (proto-)scientist.
We’re told that Bacon’s research into magic did not get very far without a wand, and he never had any formal magical training since he refused his letter. It thus seems unlikely that he enchanted his diary in any interesting way.
I’m not arguing, but how do we know that? IIRC we’ve never seen exactly what was in there, and Harry never got around to reading it. And it doesn’t sound like Quirrell to just make a gift just because it’s an “old rare item”, especially since he doesn’t quite like science and Bacon’s relevance to Harry is not that he had magic, but that he was a (proto-)scientist.
We’re told that Bacon’s research into magic did not get very far without a wand, and he never had any formal magical training since he refused his letter. It thus seems unlikely that he enchanted his diary in any interesting way.
We have only Quirrell’s word for most of that, though it seems plausible to me too.