ammar,
First let me clarify that there are many different opinions on Hadiths. 1) There are people who do not consider Hadiths to be authentic at all. 2) Muslims who do not consider it credible enough to be taken into account when making religious decrees. Though as history (which is at times bias and in-accurate) they do not have a problem with it - Usually known as ‘Ahlay-Quran’ 3) Muslims who consider Quran above Hadiths or in other words any Hadiths contradicting Quran will be deemed unauthentic. This is actually Hanafi Fiqh. 4) Muslims who consider all Sahih Hadiths (or at least Sahih Bukhari) to be authentic without question and also integral part of Muslim doctrine & especially jurisprudence.
As far as Quran’s credibility is concerned, apart from Allah’s promise inside Quran, not all reported history of Islam is through the Sahih Sitta. In fact, there are hundreds of books written through the early centuries that tell the story through their own biasness. They not necessarily go through the code system of who got this information from whom. And so we see a split in the arguments between Shias & Sunnis. What Imam Bukhari and others did was to build a structure or criteria with which they would judge which of the Hadiths are sahih & which are not. It was a thoroughly academic endeavor and they were committed to it. Imams like Imam Bukhari didn’t discriminate including the Hadiths based on their own opinions or understanding but included or excluded the sayings based on the authenticity of the reporters. As there was no written text (un like the Quran) to refer back to.
In general, not all reporters deemed authentic by the Sahih compilers can be reporting the saying accurately, due to many different reasons. It is common for me & and my brother to have a totally different understanding of what my father said a couple of days ago. Not dishonestly but it is a fact that different people view the same situation differently.
Now, it will be circular logic if the only way to prove Quran’s original text was through the Hadiths. But in fact the millions of copies of Quran around the world with not an iota of difference in Arabic text is a proof in itself. Such accuracy cannot be an accident, especially considering the fact that just within 30 years of Holy Prophet’s death Islam was present in Persia and as far west as northern Africa. Also the copies present in museums in Tashkend and Istanbul are regarded by experts to be from the 7-8th centuries & they are identical to the ones we have now. There are original manuscripts preserved in Bibliothique Nationale Paris - Royal Library, Copenhagen - Bodleian Library, Oxford and another one in Washington DC, many of which are concluded by secular archeologist to belong to Hazrat Usman’s era. But not even a single one contains a verse different from the modern day Quran.
Sahih Bukhari is considered to be the most Authentic of the Sahih Sitta by many Sunni scholars and it also contains the least number of Hadiths. There was no specific reason for focusing on it apart from the fact that it was being discussed in this thread. I am very certain about it being compiled by Hazrat Imam Bukhari [who lived from around 190s-250s Hijri] after 200 or so years. You are correct that Muwatta Imam Malik was compiled around 150 Hijri.
