What should a Muslim do if two scholars, equal in knowledge and religiosity, differ concerning the authentication or weakening of a Hadith, and he is unable to favor one over the other? Is it permissible for him to adopt either of their opinions without reservation, or would that be considered following personal inclination?

If the follower finds that the opinions of scholars are equally balanced in matters of disagreement, then he may either adopt the stricter opinion (for caution), or the easier one (because Islamic law is based on facilitation), or any of the opinions, as long as he does not intend to merely follow dispensations.

As for the disagreement among scholars regarding the authentication or weakening of a hadith, this means a dispute concerning the correctness of its attribution to the Prophet (peace be upon him). The original principle in this regard is to suspend judgment until clarity is achieved, so nothing should be attributed to the Prophet (peace be upon him) unless its authenticity is established, or its authenticity is preponderant by strong presumption based on circumstantial evidence. If there is no evidence to preponderate either opinion (authenticity or weakness), then the opinion of the one who weakens the hadith is closer to the original principle, and his opinion should not be deviated from except with a preponderant reason.