Hadīths
1) Epistemic framework
2) Joshua Little's 21 reasons why critical historians are skeptical of Hadīths
1) Prior probability of false ascription in religious-historical material
2) The earliest extant collections were recensions from the ninth century onwards
3) Hadīths are full of contradictions
4) A large number of hadīths suspiciously look exactly like later religious sectarian, political, tribal, familial, and other partisan, polemical and apologetic creations
5) Hadīths talking about later terms, later institutions, later events, and later phenomena.
6) Putative supernatural explanations for texts have a vanishingly low prior probability of explaining the existence of these reports
7) Reports of mass fabrication
8) Isnāds rose relatively late, and became widespread even later
9) Early usage of the word Sunnah was a generic notion of sunnah as good practice, which was not specifically Prophetical, and was independent of hadīths
10) A rapid numerical growth in hadīths can be observed
11) Absence of hadīths in early sources
12) Retrojection of hadīths; ratio of cited hadīths changes from mostly ascribed to followers then to companions then to the Prophet
13) Various peculiar correlations, descriptions, and content that don't make sense as a product of genuine historical transmission but make more sense as a product of later debates and later ascription preferences
14) Hadīths contradicting earlier literary and archeological sources
15) Orality means less precision in transmission
16) Extreme variation, early rapid mutation and distortion across the hadīth corpus
17) Artificial literary or narrative elements; Recurring topoi
18) Hadīths exhibit telltale signs of storyteller construction
19) Exegetical reports about the context of the Qur'ān are exegesis in disguise
20) Recurring disconnect between the hadīths and the Qur'ān in terms of historical memory
21) There was no effective method for distinguishing between authentic and inauthentic hadīths