Suggest altering partly psychological concept (7)
I believe the answer is:
gestalt
'psychological concept' is the definition.
The definition and answer can be both related to thinking as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'suggest altering partly' is the wordplay.
'partly' says the answer is hidden in the clue (part of the clue is used).
'GESTALT' is hidden in the letters of 'suggest altering'.
Can you help me to learn more?
(Other definitions for gestalt that I've seen before include "establish a pattern" , "whole of psychology" , "Organised whole, more than the sum of its parts" , "Pattern perceived as whole" .)