A student of mine read Harry Frankfurt's "On Bullshit" a while back, and he came to me interested in thinking more about the phenomenon. I'd suggested he read Gerald Cohen's "Deeper into Bullshit". He liked the essay, but he was troubled because Cohen kept using a metaphor he didn't understand. Cohen kept using expressions like: "the bull wears the semantic trousers" and "bullshit wears the trousers, not the bullshitting". My student had no idea what these meant.
The metaphor is an invocation of the old expression "Who wears the pants around here?" Which is supposed to invoke the natural superiority and sovereignty of men over women, especially in a marriage. And so 'wearing the pants' means 'is the man,' which means 'is in charge'.
This isn't to charge Cohen with sexism. The funny thing is that the metaphor was totally invisible to me, too. But to get the metaphor, you have to have been brought up in a language that uses that expression naturally. How many other expressions with this kind of sexist heritage are still around in our language? It seems a genetic fallacy to say that those who use them are sexist or that the language is sexist in its usage, but wouldn't we rather not have those sort of expressions?
I have to say, I am starting to feel the same way about similar animal-killing metaphors in ordinary parlance: More than one way to skin a cat, killing two birds with one stone, a bird in the hand is worth two in the bush….