Article poses timeless item for debate (6)
I believe the answer is:
thesis
'article' is the definition.
(thesaurus)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for thesis that I've seen before include "A lengthy essay, perhaps for degree" , "Dissertation - idea" , "Treatise advancing a new point of view resulting from research" , "He sits (anag) - treatise" , "Subject" .)