Wouldn't this be possible with some sort of Creo Animal spell with an Aquam requisite? In essense, it would be a momentary ritual (like a healing spell) that would restore it to its essential nature. I could see arguments for and against, but wouldn't a Terram Summa be a Terram Summa by essential nature once it's written?
Damaged...Yes. You can use the Laws to repair something like this..
Burned...No. You have changed the essential nature of the object...from a book, into a pile of ash and heat.
The first one is still a book, even if its damaged. The second is a pile of ash that might make good fertilizer...
Personally, I think that knowledge lost is simply lost. It makes it so much more valuable for one & balances the game.
I've come to accept that since the Guernicus have rituals that can look into the past, one could use those & re-copy the book.
Basically, if the book was of sufficiant importance that the balance of the Order was in Jeopardy, a Quaesitorial investivation would be lunched & a copy of the book would evantually be found.
Books found in an old library that are dammaged by time or burned in a fire could also be re-copied using the mighthy Time Rituals but since their value is not established, they probably will remain in their lost state for a long long time.
Healing spells could restore the physical part book but the knowledge has been lost to Time.
In a viable setting I could see an ancient artifact in Alexandria's great library that allows you to read the dammaged text if a copy of it was ever part of the Great Library. Simply bring the dammaged tome, place it on the Magical desk & the Knowledge is restored so long as it remains on the desk.
I agree with what you are saying, but I believe that violates the Magic Laws.
If you have a piece, you don't have the book.
If you have the remnants of a destroyed book, you have THE BOOK. With magic, you are replacing the damaged pieces with the ORIGINAL pieces that are missing. Even if the book is torn to pieces, as long as you have the majority of the book, you could bring the missing pieces back...no matter how small. The problem that forms here is what if someone cuts the book in half? Which part is 'the' book?
Thats why you have SG's...
Well, somebody said it before: It all comes down to the question, whether there is a essential nature which contains the complete book. I don't know any clarifying section in the rules, so this is probably up to the SG (or the troupe).
If there isn't such a EN then any attempt to reconstruct a book in this way has to cope with the limit of time: The text was there in the past, to reconstruct it you would have to look back into the past - and this ability is beyond hermetic magic.
Of course, spending some decades in the lab with access to pre-hermetic quaesitorial ritual texts and doing primary research might even work in this case.
Another approach might be taken from the section on the effects of warping.
The section on warping describes that the effects of magic occur not just on people but on furniture and objects as well. This gives a justification for saying anything repaired magically or created is inheritantly less then the original ( God remains the best creator ).
For most items like a chair or a wall, the differance is so unsubstantial that it is not worth concerning yourself with but for a detailed item where finesse is a factor ( like inked printed patterns ) this could be a significant issue.
A storyteller could thus assign a pair of factors to any attempt to heal or magically copy a book. The first would be a finesse check to make the copy as accurate as possible. The lower the roll the more the quality of the original has degraded. A very poor low may reduce the quality to the point of almost uselessness.
The second factor would be how much was being reconstructed magically. The more that is being reconstructed, the less of the original essential nature and the more room for again errors in the reconstruction/healing/repairing/copying. Less then 10% damage might have an auto reduction of 1 point in quality. 10 to 25% might be -2 quality. 25 to 50% might be -4 to quality. 50 to 75% might be -6 to quality. 75 to 90% might be -8 to quality. Last would be 90% or more reconstruction would be a -10 to the original quality. Any quality score reduced to a 0 value has reached almost meaningless quality in the reconstructed format ( It looks like the original but the words are now meaningless letters in patterns ).
Again, this is a suggestion on how you might approach such a problem. YMMV.
I think the fact that "The Transformed Folio" and "Twinning the Tome" (HoH:TL) use "group" as target when dealing with one book (as well as a hefty +5 intricacy modifier), means that the book, not being a natural object, has no identity of its own (at least as far as Hermetic magic is concerned); thus, you cannot "heal" a book - you can heal its pages individually, they're (parts of) natural objects, but the text and the assembly can only be re-done, not "healed", and information cannot be recreated. That's the view I'd take, at least.
Page 213 of 5e core, "Treasure Hunting" says that useful books cannot be magically copied, thus are valuable 'mundane' treasures. It does not defend this statement. "Creo" in the magic chapter does mention books as arftificial, hence more complex forms, and also mentions creating a mosaic if one knows what it is to depict.
I could see ruling that books with text in them do not have Platonic Forms to pull out of FormRealm, and that the complexity of the text in them rules out any simple Int+Finesse manufacture unless you have the book memorized, or the patience to let the information stream through you. Which might not save any time over scribing -- though it might justify skipping all the more realistic book creation rules in Covenants, with scribes and bookbinders and illuminators. Rule that the 5e core book creation times are already accounting for magic to make creation of the physical book easier without extra skilled labor, but someone still has to oversee the ink deposition.