I only know of two theories when it comes to the origins of the Quran:
Well, I guess I could include the third theory that's making the rounds these days:
All three theories assume that the prophet was, for the most part, illiterate. The complexity of the language, poetry and the subjects in the book would be beyond someone of his social status. It's a big book, it's a difficult language and skill and it would be amazing for someone's first attempt at publishing to be this good.
The first theory does not allow for the prophet to co-write the book. The third theory (let's just get this over with) also supposes that he did not co-write it, but it was written before his time.
The second theory (the poets) also states that separate poets wrote it for him without his help or input.
It was all done for him, but without him.
There are multiple sub-theories for the poet theory, as to who was behind this, who found the poets, who came up with the ideas behind the poetry, who funded this, but let's not get into that.
I've been hearing people say that the prophet wrote the Quran himself.
I have a few questions for historians:
The poet theory states that certain verses had a recognizable style that could be attributed to poets that were the prophet's contemporaries. Did someone recognize this at the time?
Are there now indications that tell us that the prophet did indeed write the book himself without any help? Is there any basis to that? What are these indications?
How did this idea - that the prophet wrote the Quran himself - come about? Is this more Great Man theory? While other theories propose that he got the book through divine inspiration or a funded, motivated, organized group of people, what would make people think that one man came up with the idea of a religion, came up with the rules, wrote the whole book, invented the practice and worked on spreading the religion and then was head of the group, leading its politics, warfare, etc.
Is it not more likely, and I'm speaking in terms of what the average non-historian person thinks, that more than one person worked on this project? (Rhetorical)
I see a lot of Great Man theories - from Steve Jobs to Hitler (hence the weekly "what did Hitler think of this/that") attributing so much, if not all, to one man and one man alone. Were Great Man-type theories always so prevalent in the public's mind? (Not rhetorical, I'm really curious). I'm thinking that 2-hour films obviously don't help, as they tend to overstate the importance of the protagonist and relegate other characters to sidekicks at best, cameos at worse and omit them entirely at worst.
When you say "theory", that usually implies some type of evidence. I don't know of any evidence that supports what you are saying, so it seems to fall under the category of "rumor".
Muhammad was opposed to having a written Koran, and he insisted that people memorize pieces of it to be recited. People disobeyed him and wrote down bits and pieces of it while he was alive. After his death the Koran was put together in one whole book. His followers didn't like the idea that something might be lost, and were afraid of the idea of relying on memorization.
Muhammad's idea of a congregation was to have one person who was a devoted follower, and another person who had a really good memory to contain the Koran, to be the scholar. But everybody was expected to memorize as much as they can.
I don't see any reason to believe this all didn't come from Muhammad himself.
Disclaimer:
I'm of no religious following. I study religious items like the Koran and other materials because they are historical artifacts of significant importance in the history on humankind.
Did anyone in the prophet's time accuse him of writing it himself?
There were accusations that an outsider (a non-Arab) was behind the Quran, which was a far more serious accusation. Jabr the Roman, a friend of the prophet, was accused of writing the first few Surahs. At later times other poets were mentioned to have authored parts of the book: Zayd bin 'Amr bin Nufayl, is the name that keeps coming up (both then and now), due to his style and his connection to the prophet.
There were periods and places in which the prophet had no new verses for a long time. He was mocked by the pagans who said that his own God had abandoned him. He had no answer to that. Proponents of the poet theory suggest that his poet(s) were unavailable for those periods of time.
There were more accusations of plagiarism than of him writing it himself. There was a poem by the famous poet Imru Al Qays* that had a line from the Quran (or vice versa). Imru Al Qays died decades before the birth of the prophet, yet the rest of the Sura (outside Qays' lines) keeps the style, as if written by the same author. Further study of the style shows that the poem itself might not have been from Qays at all, so it could have been quoting the Quran's lines or, if you believe the poet theory, it could have been from the anonymous poet who wrote the Quran.
Another poet whose name comes up in the "poet theory" is Waraqa bin Naufal. Another is Labid son of Rabiah ibn Jafar al Amiri. There are more, but books that suggest dozens of poets go into poor quality territory because they don't believe in maybes, possiblies or probablies, but take everything as a fact, when in reality, there is no way of really knowing for certain.