Relatively rarely. I usually try to develop an intuitive sense of where my argument wants to go before I start typing, and I'm sure many a potential comment has

Relatively rarely. I usually try to develop an intuitive sense of where my argument wants to go before I start typing, and I'm sure many a potential comment has been culled this way. When I'm typing along and find that I hit a contradiction, or something indicating something in my intuition has gone afoul, my first thought is usually: huh, I wonder how many other people think this. I've found that seeing someone's train of thought is at least as interesting as seeing where it concluded. On the other hand, there have been many times where I'd thought about commenting, but could not get an intuitive grasp of what I wanted to say, and would keep deleting the first sentence as soon as I wrote it. On those occasions, I would just press 'Back' and keep reading.