Many thanks, my lady.

No tricks here. This should be pretty easy:

According to Caesar, there are three main societal categories among the Gauls. The common folk constitute one.

You're mission, if you choose to accept it, is to deterime how our Roman sociologist (and future dictator for life) categorized the rest of Gallic society, in his Commentaries.

For a bonus, give the reasons that Caesar assumes are the reasons why many "embrace" one of these "profession[s] of their own accord."