There is one person I know who never accepts other people's opinions and ideas, even if those opinions and ideas are worthwhile. What single word might describe such an attitude?
I can't think of any nouns referring to such a person but the adjective pigheaded covers it well and the attitude is pigheadedness. You might use pighead to refer to a pigheaded person, but this is not a normal usage and I expect a lot of people wouldn't get it unless you explained what you meant.
- (pejorative) Obstinate and stubborn to the point of stupidity.
Narrow-minded (“having restricted or rigid views, and being unreceptive to new ideas”), small-minded (“Selfish, petty; constrained in thought, limited in scope of consideration, not mindful of the big picture”), and previously-mentioned close-minded (“unreceptive to new ideas or information; not open to any agreement”) are all relevant, as are some of their synonyms like hidebound (“Stubborn; narrow-minded; inflexible”) and previously-mentioned pigheaded (“Obstinate and stubborn to the point of stupidity”).
Also consider intolerant (“... close-minded about new or different ideas. indisposed to tolerate contrary opinions or beliefs; impatient of dissent or opposition; denying or refusing the right of private opinion or choice in others ...”) and illiberal (“narrow-minded; bigoted”).
Calling the person blinkered, meaning fitted with blinkers, which are “eye shields attached to a hood for horses, to prevent them from seeing backwards and partially sideways” or blindered would imply they can only see straight ahead, ie only what they are already looking at.
Some terms mentioned in previous ELU questions (1,2,3,4,5,6) are relevant. Links to wiktionary definitions are shown.
• myopic, “narrow minded”
• solipsist, “One who adheres to self-absorption and an ignorance of the views or needs of others”
• self centered, “Of a person, egotistically obsessed with himself or herself”
• uncooperative, ie not working well with others
• ossified, lit., converted to bone, fig., inflexible and rigid in habits or opinions
I think headstrong conveys the idea: (adj)
- Determined to have one's own way; stubbornly and often recklessly willful. See Synonyms at obstinate, unruly.
- Resulting from willfulness and obstinacy.
"You're the most headstrong person I've ever met," he said forcefully, and abruptly turned away.
His influence was paramount, though he protested against his master's headstrong championship of the Bourbons.
If the reason they won't accept other people's opinions or ideas is because they think their own ideas/opinions are more correct/valuable, then they're: Arrogant.
Know-it-all as defined by dictionary.com
a person who acts as though he or she knows everything and who dismisses the opinions, comments, or suggestions of others.
Sentence (made up): He's such a know-it-all, but he didn't ground his circuit like I told him to, and boy, did he get a shock!
Intransigence - refusing to accept any ideas except one's own.
One possible descriptive term is bigotry, which the Oxford Dictionaries site defines as
intolerance toward those who hold different opinions from oneself:
'the difficulties of combating prejudice and bigotry'