Even then, he goes through the typical heroic arc of:

1) Starting the story by Resisting the Call to adventure -- in a way that reveals strong character motivation (a strong desire to live)

2) He suffers a series of trials that slowly push him to the opposite view: That he must act boldly and selflessly if he is to survive (and thereby also save the Discworld)

3) He performs a heroic act (even if only armed with a "half-brick in a sock") contributing to the good side's overall victory

Although to be fair, he does tend to revert by the start of his next story.