A list of articles in not very bad shape (9)
I believe the answer is:
inventory
'shape' is the definition.
The answer and definition can be both related to thinking as well as being singular nouns.
Maybe you can see a link between them that I don't see?
'a list of articles in not very bad' is the wordplay.
'a list of articles in' becomes 'in' (I can't explain this - if you can you should give a lot more credence to this answer).
'bad' indicates anagramming the letters.
'not'+'very'='notvery'
'notvery' with letters rearranged gives 'ventory'.
'in'+'ventory'='INVENTORY'
Can you help me to learn more?
(Other definitions for inventory that I've seen before include "assets" , "List of all items in stock" , "List of items present" , "Detailed list of goods in stock" , "List of property, etc" .)