The pitfalls of being rich
An overarching theme of the novel is the pitfalls of being rich. In the novel, Ashlar is an incredibly wealthy man because of his toy company. But he is not a secure man and he doesn't have all the answers he would like despite having the resources to find out virtually any answer he wants. Fundamentally, he doesn't know who he is: is he Taltos? Or is he human? And what is the nature of his existence - and the existence of the Taltos as a whole?
Being rich, in other words, isn't a cure for the questions that plague every human who has ever existed. And being rich puts people in the spotlight while they ponder those kinds of questions, which causes turmoil.
The unbreakable bond of family
Another major, overarching theme of the novel is the unbreakable bond of family. In the novel, Anne Rice portrays multiple instances in which the bond of being family never breaks, despite situations that would normally break the bond of family. In fact, Michael had an affair and a child with Mona Mayfair, Dr. Rowan Mayfair's husband. Despite this betrayal (Michael suspected that Rowan was still alive and still went ahead with the affair anyway), Michael and Rowan remained a couple. And not only that, they remained a strong, unified front that accomplished a number of great things.
Separately, Michael and Rowan remain a couple and remain strong even though they had killed their daughter in the previous novel. Typically, this would have resulted in their relationship being destroyed; however, because they are family, their bond was unbroken.
Otherworldly influence
One of the other major themes in Taltos is the shocking otherworldly influence on the course of normal human events. In the novel, readers see that the Taltos, an alien race that was once headquartered on a remote island, are able to influence countless human events - events that seemingly didn't need to be influenced, like the death of a seemingly insignificant man.
For instance, on a small scale, the Taltos are able to influence the death of Aaron, who is Rowan's cousin. They had no credible or reasonable reason to do this, but they influenced and caused his death anyway. On a larger scale, they influence things like the Celtic raids and the spread of Christianity throughout Ireland.
