This work sets out the doctrine of positivism, arguing that human knowledge evolves through theological and metaphysical stages into a mature scientific stage in which facts and laws discovered by observation, experiment, classification, and comparison replace speculation; it outlines a hierarchy of the sciences culminating in a social science that studies society by the same empirical methods and insists that social order and progress should be guided by scientific understanding, practical reform, and secular moral principles while rejecting metaphysical and theological explanations as obsolete.