gnosonarcissist
This word is a combination of "gnosis" (knowledge) and "narcissist" (a self-centered person).  So, a gnosonarcissist is a person who believes in a self-centered way that his level of knowledge is correct and/or complete despite what others know.  This implies a lack of understanding that others might know more in areas of knowledge in either a horizontal way (breadth of knowledge) or a vertical way (depth of knowledge).
Dudley was a gnosonarcissist who believed that his own limited understanding was better than the the knowledge of others who knew much more.