This book encourages people to ask questions. Socrate's belief is unexamined life is not worth living. What is unexamined life? Life that is not being questioned.
The author also believes that the truth can be found through questioning. Even no answer can be found in the end, by questioning, you can have a fresh mind in the question.
The most important message in this book is:
WE NEED TO ASK A RIGHT QUESTION, THEN WE WILL FIND THE ANSWER.