Ancestry and honor
The most obvious theme of the book comes from the fact that these are stories about various people in the blood line of Carothers McCaslin. The stories are about honor, ancestry, and society in the South (which is often just a bunch of big farming families who stay in community; notice that the Beauchamp family is also commonly referred to, throughout the generations, meaning that those families stay in community through generations).
Although almost every story has a variation on the basic themes of ancestry and honor, the best instance of those discussions is Isaac McCaslin's three-part story from his initiation into nature by his Native American mentor (in "The Old People" he has a religious experience after being anointed with the blood of his first successful hunt), through to his rejection of the McCaslin blood line, because they are concerned with power and property. He doesn't want the honor of his ancestors if they are power-hungry men who assume their lives are worth more than black people or Native Americans.
Slavery and the brokenness of Southern law
The unfortunate language of this book is a clear reminder that these were dark times in the American South. There is a story about a runaway slave, and the owner's attempt to make his life a little better by offering him a female slave as his wife. There is a story about a white man with a black grandfather, and his desperate hopes that no one ever discover this, lest he be forced into slavery (according the broken Southern law).
Finally there is the story "The Pantaloon in Black," in which a black man in grief over the unfair, untimely death of his wife, murders a white man and is lynched in the evening by the Ku Klux Klan. These blatant, painful reminders serve to show the reader that the American South has a dark, broken past.
The brokenness of society
In this collection, the stories that stand out as the climax in the collection are the stories about Isaac McCaslin. Anointed with blood by his mentor, this young hero's impactful religious experience of meeting the primordial deer spirit "Grandfather" has shaped his experience of life. Now, in "The Bear," he realizes that the truth of his religious experience was incompatible with his own culture's views on man's relationship to nature. In other words, he has encounter true order, where man and nature coexist and co-depend, but his family men don't see that truth, and they concern themselves with social power and ownership of property, as if nature were a thing to be possessed.
