To whom does the preponderant opinion belong in ruling on hadith, between ancient and contemporary hadith scholars, especially when contemporaries authenticate what earlier scholars deemed weak, or vice versa?

The difference of opinion among scholars regarding the authentication and weakening of Hadith (definition) stems from their differing views on the narrators' conditions and the Hadith's chains of transmission. Sometimes, a later scholar may become aware of information unknown to an earlier one, or they may differ on the rules of discrediting and authenticating narrators. If major imams agree on weakening a Hadith or identifying a defect in it, then it is most likely that a later scholar's authentication of it would be an error. Whoever is proficient in this science can make a judgment as to which opinion is stronger, and whoever is not should follow a trustworthy scholar. Following the earlier scholars is more preferable.