THE SOCIOLOGISTS' POINT OF VIEW 161
For instance, suppose we have been asking some historical questions about a given period, say the beginning of the French Revolution. Let us suppose that we have asked and answered the question, What caused the French Revolution ? Now the question arises, What causes revolutions ? Here is a new prob- lem, and the previous inquiry does little to solve it. In the first place we find ourselves bound to search for a clew to the character of revolutions. What is a revolution ? In one case it is a change from pastoral industry and nomadic habits to agri- culture and fixed settlements. In another case it is a change from patriarchal to kingly government. In another the dis- placement of one religion by another. Again it is the over- throw of a dynasty, or of a theology, or of an economic theory, or once more it is the enlargement of the sphere of social opera- tions, as by the discoveries of the fifteenth century, or it is the displacement of mechanical agencies by others, as in the indus- trial revolution of the present century. What is a revolution ? It is a change within society, profoundly agitating and reorder- ing the members of society. It is as manifold as the possible ways in which society may be changed. What causes revolu- tions ? Our few and meager studies in history furnish us here and there a single case in point, but no sufficient basis of induc- tion. In one case it is intolerable oppression. In another it is successful war. In another, famine. In another, fanaticism. In another, dogmatism. In another, decay of faith. 1^ others, greed, love of adventure, race jealousy, dynastic pride, political expediency, commercial ambition, or an outbreak of sheer social madness. The historian of a certain type fulfills his mission if in one case he fully makes out the actual cause or causes of a single revolution ; say the oligarchic revolution of the Thirty in Athens, the Gracchian revolution in Rome, the successive revolutions under the Caesarian empire, the deposition of the Merovingians, the ecclesiastical revolution under Hildcbrand, the religious revolutions of the sixteenth century, the revolution of the continental state system at the close of the eighteenth century, the social revolutions in
