Émile Durkheim examines the simplest known religion, Australian totemism, to discover the permanent foundations of the religious life and human thought. Rejecting animism and naturism as systems based on dreams or linguistic illusions, Durkheim demonstrates that religion does not rest on error or hallucination. Instead, religious beliefs express real social needs and refer to a genuine empirical reality: human society itself. All known religious beliefs divide the universe into two radically opposed domains, the sacred and the profane.
Sacred things are those protected and isolated by interdictions, while profane things are the common objects of everyday life. Totemism provides the elemental form of this division, classifying animals, plants, and natural phenomena into clans that form a unified moral community, the Church. Durkheim explores totemic names, emblems, churinga, and rituals, showing how the clan projects its collective power onto external objects and animals.
Beyond religion, the book proposes a revolutionary theory of knowledge, arguing that the fundamental categories of the understanding, such as time, space, class, cause, and personality, are of social origin. Because society requires a minimum of logical conformity for its members to communicate and live together, it imposes these categories with a moral necessity comparable to obligation. Thus, reason and logic are socially constructed instruments forged through centuries of collective cooperation, uniting science, morals, and religion into a single framework derived from the creative power of society.