Identity Narratives

The mythology presented in Doctor Who seems to suggest that the entity known as "The Doctor" is merely memory. He appears to share recollection of experience with his predecessors, but not their personalities or physical make-up. Yet, even these recollections seem alterable, as his post-Time War opinions about life, death, and even about his own species, seem distinctly different from those of his earlier selves.

Given all this, why does the Doctor insist that he remains "literally" the same throughout his regenerations? Is there something essential which sustains him? Or is he, instead, the subjective summation of his own history, folded into the form of a personal narrative? Further -- is it the narrativization of that story, his story, which gives him internal consistency as a character?

In a future post, I will examine the ways in which the Doctor constructs his changing ideas of self into a personal narrative, and how he uses this discourse in an attempt to remain "the same" despite his repeated physical transformations.