Synthesized answer
The provided passage does not specify what questions remain unanswered in Carl Gustav Jung's "Modern Man in Search of a Soul." It only describes the book as a "study about man and his spiritual search" [1]. Therefore, I cannot answer what questions remain unanswered based on the given text.
Synthesized from the book passages below. Chat with the book on Feynman for follow-up.
From the book
Title: Modern man in search of a soul by Carl Gustav Jung Description: study about man and his spiritueal search