One’s trust in history can to an extent be attained through the clues, evidence, proof and fame that have been passed down generation after generation and from era to era. The clues and evidence for certain incidents in history are so many that hardly anyone can doubt in their occurrence.
Even if there are chances of forgery and alteration in some cases, such a matter has no effect whatsoever on our trust in hadiths, because we have the science of Rijal whose job is to introduce reliable narrators of hadiths to us and put aside weak and unreliable narrators; this science has developed different methods for the protection of the text of hadiths, most notably: presenting the hadiths to the imams and scholars, comparing copies, permission for narration, the indexical method, etc. It is through such means that a majority of the hadiths that are mostly gathered in hadith collections, especially the four major sources (Kafi, Istibsar, Tahdhib and Man La Yahduruhu al-Faqih) have been evaluated and the reliable ones with acceptable chains of narrators have been identified.addition to all of this, the ulema (i.e., scholars) and jurists today, especially experts in Rijal and Dirayah, like watchmen, are making every effort to preserve and refine our valuable hadiths, which after the Quran, are the most important treasure of Islam.
