We are told that before the written word, knowledge was maintained using an oral tradition. The emphasis we are being persuaded to believe is that before the written word, there were oral historians who carefully remembered and transmitted that knowledge to the next generation flawlessly. Was the oral tradition better than the written system we have today? Let's compare them.
Starting with the written history. (Yes, it came later, but it is the one we know best.) For starters, there are problems with written history. The first one to come to mind is that living languages evolve. At the time a piece of history is written, it is typically written in a living language. That means that the written words evolve from the time they are created. Written history suffers another issue: translation. When the written word is translated to another living language, the meaning is modified because the two languages may have different meanings for the translated word. Lastly, the written word presumes the reader is not able to receive any further clarification than what is written, because the text does not offer the ability to clarify any questions the reader may have. If the written word doesn't address future questions, then it doesn't have the ability to respond or clarify the future reader's questions.
Which is a major strength of the oral tradition method of conveying history. If the listener (receiver) has a question, the authoritative person can clarify the message. The other side of this positive is that the person conveying the history, when asked questions that are not directly covered by what they were taught will need to provide their own interpretation to answer the question.
There is an assumption by modern people that the oral tradition was carefully taught and repeated so that nothing would change. That would require a certain level of skill in each person to stay faithful to what the person before them transmitted. Their ego would have to be removed entirely from material being transmitted. Such an ability is a learned skill which is not completely learned by anyone. It certainly would not be a skill of an ordinary person (which explains why there were "professional" story tellers in pre-literate societies.)
In the end, unless the person writing the history is present at the event and is writing then and there (such as a court stenographer), there is some degree of oral tradition in every written document. This is even more true if the writer is not a direct witness. It would seem to me that neither written or oral history is free of issues.
Now, consider the Christian Bible. The earliest known documents are presumed to be written decades after the event by someone who wasn't present for them. The written copies we have are copies of copies, involving translations.
In general, the people who witnessed the acts and words of Jesus were not professional historians. The people they told their experiences to were not trained to present the material with clarity or accuracy. Instead, it was a group of individuals independently telling their friends and people they met the exciting things they recalled (however accurately). Those people then passed the exciting parts of what they heard on to others. (Why talk about the boring stuff... So, already we have some warping of the overall picture.) Since each person perceives what they do based on the filters they have developed, and interprets what they see based on how they filter the information that comes to them, the stories morph into things that no longer capture the whole message, but rather the various transmitter's perception of what was the exciting or newsworthy elements of the original story. Once it gets translated into other languages, more meaning is lost due to the impact of different languages not having a direct one-to-one relationship between words. Write it down in a living language and now the language departs from the original meaning to wherever the language takes it.
For example: does the word "virgin" mean "never had sex"? Can a person have anal sex and still be a virgin? Is it possible to have sex outside of marriage? Now imagine if a culture had a taboo about sex before marriage, does that mean nobody has sex before marriage? Is a taboo behavior something everyone stays away from? Now then, what if the word "virgin" simply means "a young woman before marriage." Yes, tradition and taboo suggest the virgin has never had sex, since doing so would be breaking a taboo or tradition. But can that always be true? If the word simply means young (pre-marriage), does that mean we can substitute the meaning of "young" with "never had sex"?
When we apply this idea to Mary, it is more complicated. She was betrothed when she got pregnant. Betrothal in ancient Jewish culture was a legally binding commitment preceding marriage. It involved a period of waiting and preparation before the actual marriage ceremony took place. During this period, they would often undergo various rites, rituals, and preparations, such as completing the necessary legal requirements, assembling a dowry or bride price, and making arrangements for the wedding ceremony. As a virgin, we can assume she was young. But if she is already that committed to Joseph, can we be certain she didn't have sex with Joseph? If you say you can be certain because the Bible says she was a virgin, then I would agree, she was young... period. The extra words added in were added during the oral tradition that took place over the decades. Remember, none of the apostles (assuming they even wrote the gospels attributed to their names) were present during the nine months prior to the birth of Jesus. ... And before the death of Jesus, would his mother, Mary, admit to being sexually promiscuous prior to her marriage? (Hi... I committed taboo activities...) Even if she did, would the people relating the stories of Jesus want to say she had performed taboos that resulted in the birth of their messiah?
If I told you a story and you passed it on to another person (remember, most of the people passing stories of Jesus were not trained professional oral-tradition story tellers), would you mention the boring stuff? If you really loved me and thought I was the greatest person, would you want others to know of my faults and failures? Would you gloss over my faults to highlight the reasons you think I'm great?
I'm not sure either process, written or oral, for transmitting knowledge, is better than the other. Combine them and the quality of the story degrades significantly. It makes me wonder how well my ideas will survive the future.