"You clearly don't understand...."

Thank you!

I think the fallacy of opposition is probably the closest to what I was looking for.

It also has something in common with the courtier's reply now that I look more closely at the Wikipedia definition. I had assumed it had to do with dismissing someone by saying they don't have the proper credentials and thus ignoring their argument. But now I see it is broader than that.

"The courtier's reply is a type of informal fallacy, coined by American biologist PZ Myers, in which a respondent to criticism claims that the critic lacks sufficient knowledge, credentials, or training to pose any sort of criticism whatsoever."

https://en.wikipedia.org/wiki/Courtier%27s_reply

Thanks for also pointing out Bulverism. I had not heard of that term but I'm very familiar with the tactic.

Thanks for your replies. They have given me some food for thought.

I agree in some sense there may be a Dunning-Kruger effect but I'm not sure they will admit that! Also, thanks for the Boghassian approach - I'll google that.

I thought of another example instead of the hypothetical I used before. This kind of tactic comes up periodically. Plus the topic of this second example is also something people seem to be interested in here separately from even the logical structure.

At another time and place, we were discussing whether scientists believe in consciousness exists in some form besides just being a by-product of brain functioning. I said many do not. The reply was along the lines of "If you had read Bohm, Pribram, Schrodinger, etc., you'd realize that they do accept consciousness.

I'm not concerned with the logical fallacy which is overgeneralization, I suppose, in claiming that just because some scientists do, all do.

In this case, I had read them but that's not my question. My question, however, concerns the tactic of declaring I hadn't read those scientists and was therefore uninformed.  I'm wondering if there's a name for this tactic.

Boghossian's book "How to Have Impossible Conversations" is excellent and in Kindle. Anyone who want to engage in discussions will benefit from reading it. 

As to your question, this sounds to me more like a simple putdown or attempted psychological bullying. Sort of an intellectual Argumentum ad baculum (AKA appeal to the stick, appeal to force, appeal to threat) – an argument made through coercion or threats of force to support position. If you want to engage with him, I’d ignore it and “go Boghossian” on him.

Thanks for the recommendation on the book. I'll put it on my list.

Although I don't really plan on engaging with him much further in this case, I'll remember your advice.

Much of this is practice for when I publish some of my research and I'll be forced to defend the ideas in earnest. At that time, I'll want to "go Boghassian" where possible in order to reach some kind of understanding. It's very valuable for me to become aware of these issues beforehand.

Thanks, I'll consider that.