Taqlid (Deference to Scholarly Authority)

Definition
Linguistically, taqlid denotes placing something around the neck so that it encircles it like a necklace.
Technically, it means following someone whose statement is not, in itself, an authoritative proof.

By the clause “someone whose statement is not an authoritative proof” we exclude following the Prophet (peace and blessings be upon him), following the consensus of the scholars, and following a Companion—if we deem a Companion’s statement to be proof—because none of those instances are called taqlid. They are, rather, adherence to recognized proof, though the term taqlid may be used for them figuratively and by way of broad usage.

Situations in Which Taqlid Is Permissible
Taqlid is resorted to in two cases:

1. The follower is a layperson who cannot determine the ruling on his own; his duty is therefore taqlid, for the Almighty says, “So ask the people of knowledge if you do not know” (al-Nahl 16:43). He should follow the scholar he judges to be the most knowledgeable and the most scrupulous; if two appear equal to him, he is free to choose either one.

2. A mujtahid is confronted with an incident that requires an immediate ruling and has no time to investigate it; in that circumstance taqlid is permissible for him. Some scholars stipulate that taqlid is allowed only if the question does not concern the fundamentals of faith that must be held with certainty, for matters of creed demand conviction, whereas taqlid provides mere probabilistic knowledge.