I think it should be fairly clear from the context that it is the act of self expression that is alluded to, in this particular case the act of writing. It is

I think it should be fairly clear from the context that it is the act of self expression that is alluded to, in this particular case the act of writing. It is similar to the use of the word act in "you act surprised". This is something you can say, even in writing, and people will generally understand what is meant. What is important for a civil debate is not to pick on words, but to try to understand one another. If someone you are responding to writes something that can be understood in several ways, choose the one that is more flattering to their side of the argument.