This book examines the concept of social pathology as it figures in the thought of Plato, Rousseau, Hegel, Comte, Marx, and Durkheim, demonstrating what it means to describe societies as "ill" and what the fact that we are so often drawn to conceiving of social problems as illnesses says about social ontology, or the kind of thing human society is. It explores the connections between social pathology and such phenomena as alienation, anomie, ideology, and social dysfunction and argues for the continuing relevance of the idea of "social sickness" for social critique. The aptness of the concept of social pathology in comprehending social ills points to important respects in which human societies are to be grasped as functionally-constituted, "living" beings and therefore as analogous to biological organisms, even if there are equally important respects in which the analogy does not hold, deriving primarily from the self-conscious and potentially free character of social activity. Human societies are understood as "spiritual" entities, the functions of which extend beyond material reproduction to include freedom, recognition, and self-transparency.