What is the theme in The Story of Philosophy by Will Durant?

From the beginning of philosophy with the early Greeks, thinkers regularly get in trouble with the government to which they are subject. One of the continuing areas of interest in the history of philosophy is politics. Socrates claims philosophy begins at the point when assumptions and ideas are challenged. Philosophers question the methods and manners by which they are ruled. Consequently political philosophers are at risk of getting in trouble because of challenging authority. A continuing theme in Durant's work is the frequency with which philosophers risk getting in trouble with their government.