Word to describe someone who plays 'devil's advocate'

There are two words that are synonyms of devil's advocate, however neither is commonly used and one actually has a negative connotation.

The first is polemicist. This one carries an implication of (viciously) attacking another's point of view, so this is not what you want.

The second is apologist. This term is slightly more neutral, referring to someone who defends a position that is being attacked by others. It might work, it might not.

In my opinion, the best term to use to describe this person is the original term: devil's advocate.

That it is difficult to find neutral let alone positive terms speaks volumes about our language. Devoted self-questioner, positive skeptic, skillful doubter, rational Buddhist.