I started reading this book looking for a comparison of the messages of the four title authors. That is not what this book is. It does give an interesting overview of the lives of each author, which I found interesting. The author instead spends the most time describing each authors relationship with Christianity, which could be interesting if that is what I was searching for, but it was not. Christianity was a major theme for some of these authors, but not all, and it felt like it overshadowed other aspects of their works. I went into this book hoping to gain a better understanding of the main concepts of some philosophers that I was not very familiar with, and I feel that I did not achieve that.