Posthumus offers the first revisionist history of the Lakotas' religion and culture in a generation. He applies key insights from what has been called the "ontological turn," particularly the dual notions of interiority/soul/spirit and physicality/body and an extended notion of personhood, as proposed by A. Irving Hallowell and Philippe Descola, that includes humans as well as nonhumans. All My Relatives demonstrates how a new animist framework can connect and articulate otherwise disparate and obscure elements of Lakota ethnography. Stripped of its problematic nineteenth-century social evolutionary elements and viewed as an ontological or spiritual alternative, this reevaluated concept of animism for a twenty-first-century sensibility provides a compelling lens through which traditional Lakota mythology, dreams and visions, and ceremony may be productively analyzed and more fully understood.

Posthumus explores how Lakota animist beliefs permeate the understanding of the real world in relation to such phenomena as the personhood of rocks, ghosts or spirits of deceased humans and animals, meteorological phenomena, familiar spirits or spirit helpers, and medicine bundles. All My Relatives offers new insights into traditional Lakota culture for a deeper and more enduring understanding of indigenous cosmology, ontology, and religion.