Did you say Unreliable? I thought you said Unreliable.

[Terrance]

The concept of the unreliable narrator was introduced to Lit-crit 
by Wayne C. Booth in 1961. Booth's classic definition of the unreliable
narrator has survived in nearly all narratological textbooks: 

"I have called a narrator reliable when he speaks for or acts in
accordance with the norms of the work (which is to say the implied
author's norms), unreliable when
he does not" (158-59). 


Recently, however, critics have argued that the
existence of an implied author is neither a necessary nor a sufficient
requirement of unreliable narration.


A reader-centered approach (no surprise there) to unreliable narration
has emerged. 

Unreliable narration can be explained "in the context of frame theory as
a projection by the reader who tries to resolve ambiguities and textual
inconsistencies by attributing them to the narrator's unreliability.


Hence,  unreliable narration can be understood as an interpretive
strategy or cognitive process.