What are the internal and external conflicts of Reverend Hale in The Crucible?

Reverend Hale's external
conflicts initially relate to his attempts to discern evidence of witchcraft in Salem, then to
find and arrest those who have been accused. Finally, he comes into (external) conflict with
Danforth and the court, attempting to convince them that the trials are based on false
evidence. 

Hale is also continually in conflict with Proctor, though the
conflict changes. First Hale and Proctor disagree over Abigail's accusation against Elizabeth.
Later, Hale tries to convince Proctor to save his own life by confessing to the crimes he has
been accused of committing. 

Hale's internal conflicts relate to his shifting
beliefs in the validity/reality of the claims of witchcraft in Salem.

Hale embodies many of the moral contradictions of the play: he is a
man of integrity who, although at times misguided and overzealous, is willing to change his mind
when confronted with the truth.

Hale undergoes a crisis
as he realizes that Proctor was right and Abigail has been lying the whole time. The charges are
all false. People have died because of Hale's belief in Abigail's stories and his own belief in
witchcraft. 

This leads him to repent and to suffer a rather extreme sense of
guilt, saying: 

there is blood on my head! Can you not
see the blood on my head!