Sort of ladies captivated by author's belief in perfection (8)
I believe the answer is:
idealism
'belief in perfection' is the definition.
'sort of ladies captivated by author's' is the wordplay.
'sort of' indicates anagramming the letters.
'captivated by' indicates putting letters inside.
'author's' becomes 'im' ('I am' referring to the author of the crossword).
'ladies' is an anagram of 'dealis'.
'dealis' put into 'im' is 'IDEALISM'.
(Other definitions for idealism that I've seen before include "A view of Berkeley" , "Utopian pursuit" , "Economise" , "Thoughts of perfection for miladies" , "Pursuit of the perfect" .)