Recently, some anthropological researchers have prioritized the interaction between biology and culture in trying to explain human variation and avoid reductionist views such as the racial worldview. Such scholars refer to this interaction as human biocultural diversity. It is a holistic view that highlights, as Elisa J. Sobo says, “all population-based human variation generated in or reflecting the dynamic, synergistic communion of biology and culture, neither one of which can function without the other.” In this viewpoint, biology and culture co-create each other. But at what point does the cultural become biological? And at what point does the biological become cultural? And how do we bypass dualism in considering the interactive merge? I propose that the Spinozistic view of the human being can help resolve this conundrum, i.e., a rejection of the dualistic notion of body and mind by offering Baruch Spinoza’s monistic view so that body is identical to mind. That is, following Spinoza, biology will be placed under the attribute of Extension and culture under the attribute of Thought, and then argue that biology is one and the same thing as culture as mind and body are the same thing in Spinoza’s Nature (Substance/God). Viewing biocultural anthropology through Spinoza’s philosophy could lead us to our most advantageous well-being in terms of social organization.