Criticism may arise on any of the following grounds:
These are ten: five pertain to ʿadāla (uprightness), and five to ḍabṭ.1 They are not separated into two groups, so that they can be arranged in descending order of severity.2
A muʿallal ḥadīth contains a hidden defect (ʿilla) damaging to its soundness, detected by warning signs in sanad and matn that arise to one familiar with the art.
The Ḥanafīs classify narrators by ʿadāla, ḍabṭ and fiqh, with the mastūr as a disputed third category and the majhūl, whose narration falls into five cases
The science of jarḥ and taʿdīl: its two grounds, ʿadāla and ḍabṭ, when jarḥ must be explained, when it overrides taʿdīl and who needs tazkiya.
When a narrator's solitary transmission is suspected, others' parallel narrations are mutābaʿa or shāhid; the pursuit of these is al-iʿtibār.
