In The Mayor of Casterbridge, what is Michael Henchard's tragic flaw, and how can I describe it in a thesis statement?

Michael Henchard's heroic tragic flaw is related to
Hardy's theme of how a person's inner character traits interact with blind Fate. Hardy's
point is that for every choice a person makes, future choices are either broadened or
narrowed and Fate is either advanced or forestalled. An example of this is that early
on, Henchard resisted disencumbering himself of Susan and the baby, even though he
believed they were holding him back. With these moral choices, Fate was forestalled. Had
Henchard continued in this path of moral choice, Hardy suggests, his end in life would
have been a different one. Conversely, at the drunken moment that he agrees to a drunken
opportunity to sell Susan and their baby, Henchard makes a decision that so curses and
narrows his future choices that a blind destructive Fate is aided and hastened. It takes
some mental effort to keep the threads of Fate and Choice separate, especially when
Hardy is showing their interaction, but the message is that had Henchard displayed
different character traits, Fate would have brought forth different opportunities, or
the opportunities Fate did bring forth would have been rendered
powerless.

That being said, Henchard's tragic character
flaw is the dichotomy within his nature. He is honest to a fault as seen when he doesn't
deny the furmity woman's accusations. Yet he is also self-protective to a fault as seen
when he disencumbers himself of his family because they are holding him back and when he
lies to Newson by saying Elizabeth-Jane is dead.  He is faithful to his word and always
conducts his business on the highest standards. Yet he can explosively declare rash and
cruel things the pursue them as though they were reasonable and right things, again as
in the sale of Susan and the baby. He has determination and will power and can keep a
promise for years and decades. Yet he can't think with foresight and foresee disastrous
ramifications of impulsive thoughtless acts. He has a deep sense of justice, as in his
attitude toward himself when his is alone and forsaken at the end of his life. Yet he is
petty and mean spirited as was the case in his feelings toward the loving and accepting
Elizabeth-Jane the morning after the two paternity revelations. It is this unintegrated
duality, this combination of light and dark, that constitutes Henchard's tragic flaw:
though he has high values, he lacks the ability to think through and foresee future
affects of present choices and acts.

A good thesis
statement might incorporate this dichotomy and duality, this combination of light and
dark impulses, and relate it to Hardy's theme of interaction between personal choice and
Fate. Possibly something like this might work: Henchard's tragic flaw is the dark versus
light dichotomy of his nature that proves character-determined personal choice spurs on
or forstalls the realization of Fate.