Several important ideas are explored in this novel, largely through the conflicts between two societies: the Lenni Lenape tribe and the white settlers.
One major idea is the search for personal identity. True Son, the protagonist, is torn between both of these cultures. As a young white boy who was captured and then raised by Cuyloga and his people, later to be returned to his biological parents, True Son struggles with his love for Cuyloga and the Lenni Lenape, his growing affection for his little brother Gordie, and his loneliness as he is trapped in a white society whose customs repel him. True Son's search for identity has no happy ending; at the conclusion of the novel, he effectively belongs in neither culture.
Another idea that develops is that of racial prejudice and stereotyping. The Lenni Lenape and the white settlers hold each other and their customs in contempt. The settlers view the Native Americans as "savages," and the Lenni Lenape believe the settlers to be as foolish and immature as irresponsible children, not understanding what in the world truly should be valued and treated with respect. Neither group can find any humanity in the other.
Also, the novel explores the idea of freedom vs. captivity in an ironic way. As a small boy, John Butler was taken captive by the Lenni Lenape, but grows up as True Son, enjoying the freedom of the natural world. When True Son is returned to freedom (as the settlers view his release), he feels instead that he has lost his freedom and has been made a captive of the white settlement. Freedom, then, is presented as a subjective state of mind and spirit.
Because all of these ideas are very relevant today, much can be gained from reading True Son's story.