I recently purchased a copy of a nonfiction book that I'd recommend for any aspiring Seraphinian linguists or would-be decipherers - Lost Languages: The Enigma of the World's Undeciphered Scripts, by Andrew Robinson.

The first part of the book describes how 3 different writing systems were deciphered - Egyptian Hieroglyphs, Linear B, and Mayan glyphs. It succinctly describes the methods that were used to successfully figure out these writing systems, and although I had already read separate books on all three of these writing systems being deciphered, it has still been informative and given me more insight into how Seraphinian eventually might (or might not) be deciphered. These 3 chapters mention how allographs (letters/symbols with different appearances but similar phonetic values, such as "a" and "A") have posed problems - like Seraphinian, it was sometimes difficult to tell when 2 letters in these writing systems were entirely different letters, or the same letter written with trivial differences that don't change the meaning.

A method used for classifying undeciphered languages that the book mentions is character count: At least in natural languages, alphabets & consonantal scripts have the fewest number of characters/symbols (20-40). If there are 40 to 90 different characters in a writing system, it's probably a syllabic script, like Japanese kana. And if the script has characters numbering in the hundreds or thousands, it's a logosyllabic script such as Chinese. Of course, this doesn't take into account any intentional obfuscation by Serafini, such as redundant allographs, perhaps such as 40 different characters to represent the alphabetic letter "r".

Another frequently useful item that the book mentions for deciphering writing systems has been to look at numbers, dates, and names. The Seraphinian page numbering system has already been cracked, but looking at numbers, dates, and what appear to be proper names (and words around them) in the main text of the Codex may help to find words/affixes that indicate plurals, a person's gender, or words that mean "date of birth" and "date of death".

I haven't even reached the last 8 chapters of the book, which describe as-yet-undeciphered writing systems, but I can tell that it will be an interesting read and may give me more ideas at how to try to approach deciphering Seraphinian. Hopefully I will be fully inspired at the end of the book to get back to my procrastinated examination of the Codex's writing.