Final answer:
The conflict in the Mark Twain excerpt is an internal one, involving Twain's initial confidence being undermined by self-doubt due to external pressures. This highlights the story's theme of relying on one's own knowledge rather than second-guessing oneself.
Step-by-step explanation:
The type of conflict presented in the Mark Twain excerpt is an internal conflict. This conflict arises as Twain becomes torn between his initial confidence in running a crossing and the self-doubt instilled by Mr. Bixby's actions, which include sending more people to rattle his confidence. The internal struggle that Twain experiences as he second-guesses his abilities underscores the story's theme: the importance of relying on one's knowledge and training instead of succumbing to doubt.
This conflict is pivotal in the development of both the story's theme and overall purpose. Twain's anecdote serves to instruct the reader that self-reliance and trust in one's own skills are key to overcoming internal uncertainties. It illustrates that the conflict, whether it be an internal struggle or an external clash, is central to revealing the characters' values, needs, or interests within a narrative.