Case 1 — Companion: A blind believer met the Prophet ﷺ during his lifetime and died Muslim; physical sight was not required to establish the encounter.
Case 2 — Successor: A Muslim met a Companion but never met the Prophet ﷺ; the person belongs to the Successor generation.
Case 3 — Mukhāḍram: A person lived through the pre-Islamic and Islamic eras without meeting the Prophet; this is not automatically a Companion.
Case 4 — Mawqūf or maqṭūʿ: A report ending with Ibn ʿUmar is mawqūf; one ending with al-Ḥasan al-Baṣrī is maqṭūʿ. Chain soundness is a separate question.
Governing method: identify the relevant person and generation, determine the endpoint of attribution, and then assess the particular transmission route for reliability.