in his monograph Munirul 'Ain fi Taqbil al-Ibhamayn, Imam Ahmad Raza includes a very useful discussion on the principle of hadith that all non-SaHiH aHadith are not necessarily mawdu. those who understand urdu [and even arabic as a lot of the quotes are in arabic too] please read the discussion which starts from the beginning of the book and covers at least half the 200-page monograph http://alahazratnetwork.org/dlibrary/alahazrat_books/munirul_ain/index.htm
