The early circumstances and education of Godwin and of Mathilda's
father were different. But they produced similar men, each
extravagant, generous, vain, dogmatic. There is more of Godwin in this
tale than the account of a great man ruined by character and
circumstance. The relationship between father and daughter, before it
was destroyed by the father's unnatural passion, is like that between
Godwin and Mary. She herself called her love for him "excessive and
romantic."[xiii] She may well have been recording, in Mathilda's
sorrow over her alienation from her father and her loss of him by
death, her own grief at a spiritual separation from Godwin through
what could only seem to her his cruel lack of sympathy. He had accused
her of being cowardly and insincere in her grief over Clara's
death[xiv] and later he belittled her loss of William.[xv] He had also
called Shelley "a disgraceful and flagrant person" because of
Shelley's refusal to send him more money.[xvi] No wonder if Mary felt
that, like Mathilda, she had lost a beloved but cruel father.

Thus Mary took all the blame for the rift with Shelley upon herself
and transferred the physical alienation to the break in sympathy with
Godwin. That she turned these facts into a story of incest is
undoubtedly due to the interest which she and Shelley felt in the
subject at this time. They regarded it as a dramatic and effective
theme. In August of 1819 Shelley completed _The Cenci_. During its
progress he had talked over with Mary the arrangement of scenes; he
had even suggested at the outset that she write the tragedy herself.
And about a year earlier he had been urging upon her a translation of
Alfieri's _Myrrha_. Thomas Medwin, indeed, thought that the story
which she was writing in 1819 was specifically based on _Myrrha_. That
she was thinking of that tragedy while writing _Mathilda_ is evident
from her effective use of it at one of the crises in the tale. And