While this might be my shortest theory yet, I think it might actually be to most groundbreaking as far as explaining the One Piece world. You can also watch the video version by clicking the video below. Anyway, enjoy!
Poneglyphs + The Voice of All Things
It was stated by Rayleigh that what allowed Roger to read to Poneglyphs was his ability to hear “the Voice of All Things.” While some might accept that answer, others like myself had a difficult time grasping how someone could write the language, even if they could hear something in the Poneglyph that betrayed it’s meaning.
We know that Oden was w/ Roger, however, that doesn’t offer a firm explanation either. According to his retainers, only the “means to read and write the ancient Poneglyph” was passed on; it was not taught nor do the clan’s members know how to read + write the language fluently.
This suggests that they might possess some decoder/translator/key of sorts, but we can’t be sure. However, this doesn’t make sense either considering that Rayleigh said it was the Voice of All Things that allowed him to learn the history. In other words, Oden might have been the one to inscribe the new glyphs onto the golden ponyglyph, but Oden wasn’t the means for him learning it’s secrets.
So how did he do it?
We learned in the most recent chapter that all attacks have a will + aura to them. Rayleigh says attacks, but what’s really going on here? What is an attack anyway? An attack is just a specific example of action. In other words, all actions have a will or intent behind them!
If this is the case, then you carry your intent in all things that you do. That means that in making the ponyglyphs, ships, swords, ect. these things are being imbued w/ your intent or will. Though Roger couldn’t read the Poneglyphs, he could feel or hear their meaning, giving him the ability to both learn the true history as well as write it. He might have been able to write it on, say, paper, but he couldn’t write it on the Poneglyph himself. However, there’s a special technique, the only means of engraving the Poneglyphs, that exists exclusively in the Kazuki clan. The markings left by Roger may have been the work of Oden, following the instructions of Roger.
And this, might be the true meaning of the voice of all things, living things passing their will onto their creations!! I think some translations actually use “the will of all CREATION,” which is increasingly interesting. Anyway, I think we might have stumbled onto one of the biggest secrets in One Piece, crazy!
*Theory by TwinKidd_B