I also post or comment under the name Mister Pregunto. This is not to be deceptive, but primarily because these pesonae serve different functions.
Mr. Pregunto is very interested in the Art of the Question.
Copernicus wants to prick the world's conscious--making it a bit more self-critical rather than other-critical. His plan was to goad the world into improving its thinking. Unfortunately, Copernicus' big mission got tiring very quickly, so now he is thinking of an early retirement, leaving Mr. Pregunto in charge.
Unofficially, I sometimes also comment as Ptarmigan, who has no blog and no fixed agenda. I expect Ptarmigan will soon be going the way of the dodo.
I try to remember not to use different personae to comment on the same post, but (alas) I have mistakenly done so at least twice in the recent past. This was unintentional.
That about sums it up for my little personality disorder. Three voices in one head does make a crowd.