Heart is trying to show good taste (8)
I believe the answer is:
artistry
'good taste' is the definition.
The answer and definition can be both related to thinking as well as being singular nouns.
Maybe there's a link between them I don't understand?
'heart is trying to show' is the wordplay.
'to show' indicates the answer is hidden within the clue.
'ARTISTRY' is hidden within 'heart is trying'.
Can you help me to learn more?
(Other definitions for artistry that I've seen before include "Finesse" , "poetic skill" , "Creative workmanship" , "Virtuosity - craftsmanship" , "Creativity" .)