I was responding to Historiann's thread that included a link to the post on "mansplaining" when I started thinking about Freud, De Beauvoir's "The Second Sex" and generally about women, men, image, representation, and power. I've adapted that comment here, since I didn't want to hijack Historiann's comments thread any more than I already had!
It would seem at first that "mansplaining" doesn't really need to refer only to men talking to women but that it applies more generally to posturing in dialogues to assert one's power. That was my first impression, although I had a gut feeling that there is a difference in the dynamic when a man condescends to a man and when (a certain kind of man) condescends (in a certain kind of way) to a woman.
If the dialogue takes place between two men, is it about jockeying for power? In other words, does the mansplainer enter into the discussion as if it is a competition for authority between two people, each of whom could conceivably "win" the competition? Earlier, I used the (classy) metaphors of pissing contests and dick-measuring contests to describe some of the dynamic I see between men who are condescending to each other as a way of racing to the top. But in terms of image and representation, these size-related competitions are one of the most common ways we represent one man's power over another man. Both men have the same "weapons" to be deployed in the competition, although one will win over the other in the end.
In contrast, a mansplainer talking to a woman is engaging in a dialogue that cannot be represented as a competition between equal parties. From the mansplainer's perspective (thanks, Freud!) the woman is simply not even in the running. She cannot compete in the battle of size because she just doesn't have a phallus. At all. Thus, to me, “mansplaining” refers to that implicit assumption that the woman isn’t just the lesser party in the race for authority, but that she can’t even take part in the competition?
And that is precisely why it is so extraordinarily frustrating! The mansplainer starts from the assumption that the woman he is addressing isn't just subordinate to him, but that she literally cannot claim authority to speak. Ever.