I also post or comment under the name Copernicus (Copernicus Now). 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 original plan was to goad the world into improving its thinking. Unfortunately, Copernicus' big mission got tiring very quickly, so now he has gone into semi-retirement, leaving Mr. Pregunto in charge.
Unofficially, I sometimes also comment as Ptarmigan, who has no blog and no fixed agenda. I wonder if 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 a couple times in the past. This was unintentional.
That about sums it up for my little personality disorder. Three voices in one head do make a crowd.