Many of us argue about the rights and wrongs of Muhammeds teachings relying on hadith to argue one way or another. Are we falling into a trap in assuming that these hadith are in fact historical facts and merit such debate when in fact they should all be cast aside as totally unreliable thereby halting the debate from the onset?
Historians rely on the historical method.
https://en.m.wikipedia.org/wiki/Historical_method
How does the 'science' of hadith compare to this in establishing sound grounds to even start a debate?
What im getting at is it possible to strip away the junk to leave behind a reliable core from which we can then begin to discuss the merits either way?
You have to take into account that the hadiths/sira (biographies of p. Muhammad) began to be written only 100-220 years after the death of prophet Muhammad. Regarding the ahadith, they were derived from oral legends and hearsay sayings attributed to narrators usually comprised of companions and family of prophet Muhammad, thus making them quite difficult to verify. Islamic scholars would visit the intellectual centers of the Muslim world and compile hundreds or even thousands of oral ahadith related to numerous topics, assess their reliability individually by grading them as "Sahih"/ authentic or "Dhaeef"/weak and add the ones considered "Sahih" to their hadith books. The criteria of grading as "Sahih" and the levels of objectivity varied with each scholar. The early systems of grading were generally subjective and unreliable (in terms of assessing who is a reliable narrator, whether a widespread hadith was considered reliable, etc) but with the introduction of new grading systems and commentaries later on (especially in the 20th century), most hadith collections with fragility and low standing were discarded due to their unreliability. The ones who are still used are considered to be authentic by Islamic scholars but again, it is very difficult for historians to make sure of that objectively for the reasons mentioned above.
In Sunni Islam, six hadith collections are renowned for their reputed authenticity even when assessed with modern hadith authenticity measuring standards while Shia Islam has four canon major hadith collections. Even with modern hadith standards, the authenticity of some ahadith have stirred up controversy due to reasons which opponents claim to collide with the Quran.
Also, I think it's worth mentioning that Shias takes a liberal stance when it comes to ahadith and discarding them while Sunnis strongly hold on to the belief of the authenticity of their six hadith books.
In addition, I believe that the Quran should be used to establish sound grounds before initiating a debate since it was compiled during the reign of Uthman when many companions of the Prophet were still around to verify it as not being tampered with, etc.
TL;DR: Hadith is not very reliable while the Quran is.