I've been reading this book to get insights into stoic philosophy. One of the earlier stoic philosophers was Marcus Aurelius, a competent roman emperor. It's amazing to see how exactly similar people are today to those times when I read Marcus' meditations. This book is actually a collection from many stoic philosophers.
For people who are suffering, stoicism is an incredible source of relief. It teaches indifference and a 'passive' reaction to external events. In many respects, it bears a remarkable similarity to the ethical teaching of Siddhartha Gautama (c. 563 - 483 B.C.) and Buddhism, which is grounded in the four noble truths:
1) all life has suffering;
2) suffering is rooted in passion and desire;
3) happiness is freedom from the passions;
4) moral restraint and self-discipline is the means by which one becomes free from suffering.