I approached this book asking "What is creativity? Am I creative? How has this affected my relationships with co-workers?"
What is creativity? "the process of challenging accepted ideas and ways of doing things" or "seeing ideas or objects in a different context". Looking back at when I've been working, I've tended to be excessively creative, with scant insight or consideration for the consequences.
According to this book, if you have past experience of the class of problem you are tackling, logical/convergent thinking taps our personal experiences. When dealing with new problems, creative/divergent thinking must be employed.
Later on, this book provides a process so that even the most unimaginative reader has a decent chance to be creative and it will improve the creativity of the most radical reader.