First link: I choked on my tea. thanks. an argument on ethics almost killed me.
Second link: So that's why i've been doing continental philosophy...
I came across the second link 5 or 6 years ago and to this day I don't understand what the argument with H2O and xyz is supposed to be (not that I've bothered actually reading the meaning of meaning, even though I have a pdf of it. Maybe I'll do that.)
Putnam's idea is that standing in certain relations with XYZ-stuff instead of H2O stuff would give a person's thoughts different content. So if my twin-earth twin and I have identical mental states (described from the inside) but have the relevant relations with XYZ and H2O, respectively, we have different propositional attitudes (and "water" means different things in my mouth and my twin's).
how that relates to the trolley thing I have no idea.