I have been thinking ... shouldn't there be some sort of arcane connection between a copy of a book and the original from which the copy is made?
If so, how long should it last? I'd say: Indefinite, perhaps until either book is altered in such a way its Quality is changed - e.g. if it's glossed, clarified, damaged etc.
And which way(s) should the connection work?
The most "natural" one would be for the copy to be the arcane connection to the original, just like someone or something's "byproducts" (from a horse's dung to a magus' written works) are arcane connections to the "maker"; this would also increase the paranoia of magi about selling/sharing copies of their precious books.
On the other hand, the original being an arcane connection to the copy (and not viceversa) would make hunting for the very initial copy something with concrete magical benefits, which is a good thing from a storytelling point of view.
Not "physically". But neither is a letter written by a person, or that person's favourite inkpot - despite both being canonically arcane connections to that person.
Hmm. I was convinced that a person's progeny would count as an arcane connection to the parent (the idea being that a copy is the "child" of the original) but it may be something we just made up at our gaming table?
A book would be an Arcane Connection to the Author. Yes, because the author invested time and effort to write it. A month for a Tractatus copied, and one or more seasons for a Summa.
For some reason, to me it seems that a copy of a book should have a stronger "mystical link" to the original than to the scribe doing the copying.
Also, there are certainly many ways to purposefully create arcane connections between stuff. The main question here is, however, what kind of mystical connections (if any) exist "naturally" between "parent book" and "child book", whether any scribes etc. want them or not. I think these can make for good stories and make acquiring books something with interesting mystical implications.
Arcane Connection by Contagion, rather than Sympathy.
A part of the book-binding should be an Arcane Connection to the original book for a while, especially if you fix the AC. However, if you incorporate it into another book, are you not diluting its connection to the original? (by changing into something different from merely a portion of the old book) Unless the part is used as a book mark, but then it is the book mark that is a connection to the original book, not the copied book.
Quckly: A physical book is an AC to its maker, and a physical letter an AC to its writer (ArM5 p.84).
But we also have (TME p.99f Limitations of Hermetic Theory): the words in a book (let's call them a text here) cannot be read, understood or analyzed by magic from that book. For that one would need to read the mind of a person who once understood or wrote that text.
A text (e.g. in a physical book, or recited from memory) is by itself not a physical, mental or magical object. I consider it an instance of communication depending on a language community. By itself it is not an AC to anything and there is no AC to it.
It is hence also not connected by ACs to any media storing it somehow - like the memory or the book above.
If somebody copies words from one book to another he copies a text. So this also cannot establish ACs between the master book and its copy. If somebody builds a device following a particular instruction, he acts upon a text. So this does not establish ACs between instruction and device either.
Something, the connection, is an Arcane Connection to something else, the target, if the connection was very closely associated with the target, often by being a part of it.
Note that I am not saying that any physical instance of a text should have an arcane connection to any other physical instance of that text. I am talking specifically about a physical book, and the specific physical book it was copied from. I think that strongly qualifies as "very close association" between the two.
Note that in some languages, these are called the "child book", and the "parent book"; a wording that was used to justify the famous, historical "cow and calf" ruling - which was not about copying a text, but about copying a physical book to make another physical book.
I disagree. The physical books don't really have anything in common, let alone a "very close association". The textual contents may be the same, but that has gone through too many steps to create any close association between the physical books.
Reading the first book doesn't create a "very close association" between the book and the reader.
Writing the second book does create an association between the writer and the book, but since the reader/writer doesn't have such an association with the first book he can't (and won't) transfer it to the second book.
A letter is an arcane connection to its author because it is a representation of the author's ideas.
a tractatus contains words, not ideas, so a copy does not represent an arcane connection under this principal.
I would however allow and exact copy- same penmanship, same binding, same type of vellum and ink, to be a sympathetic connection however. It would likely have to be copied with magic to accomplish this, and likely not for as long as a letter would be a connection to it's author.