If someone is insecure in their views, maybe they are too open minded about different things and their opinions or views might be easily swayed. This could be a source of discomfort for them resulting in the insecurity.
People who are more secure in their views could be that way because they have a lot of worldly experience and intelligence regarding certain things and they are quite comfortable expressing themselves about such matters.
If someone is adamantly opposing another person’s views, maybe it is because they always feel they have to be right or their opinion is the only one that matters most. This is selfish, in my opinion, and it doesn’t leave a lot of room for healthy debate between 2 or more people. As far as someone protecting themself from learning a new opinion, that could possibly be stubborness and/or irrationality in regards to not being open minded about different things. It could also depend on the topic being discussed. This line of reasoning might be a viable cause of why some people don’t like to engage in debates or discussions. Additionally, they might want to avoid possible chances of something deteriorating into an argument.
I feel pretty secure in my views and I can certainly be passionate in a debate where I have strong opinions on something. I won’t let it get to the point where others wouldn’t have an equal voice, though, in offering their own input because that really isn’t fair and it would limit the effectiveness of everyone’s contributions. I’m open minded and I always enjoy a good discussion/debate and especially on matters that I have a decent amount of knowledge about because then I can bring quality information to the table, so to speak, in these instances.