Scientific history teaches that without war many revolutions could never have taken place. One of the greatest problems of future government is to reconcile democratic equality with hereditary inequality among the people. Governments differ much more in form than in substance, and make progress when the resultant activities of the citizens direct and control them. With this in mind, a few principles of revolutions may be instructive in connection with the present European situation. 1. The causes of revolutions are summed up in the word "discontent," which must be general and accompanied with hope in order to produce results. 2. Modern revolutions appear to be more abrupt than ancient. Contrary to expectation, conservative people may have the most violent revolutions, because of not being able to adapt themselves to changes of environment. 3. Revolution owes its power to the unchaining of the people, and does not take place without the aid of an important fraction of the army, which usually becomes disaffected by power of suggestion. 4. The triumphant party will organize according to whether the revolution is effected by soldiers, radicals, or conservatives. 5. The violence is liable to be great if a belief as well as material interests are being defended. 6. For ideas which cause violent contradictions are matters of faith, rather than of knowledge. 7. If the triumphant party go to extremes, bordering upon absurdities, they are liable to be turned down by the people. 8. Most revolutions aim to put a new person in power, who usually tries to establish an equilibrium between the struggling factions, and not be too much dominated by any one class. 9. The rapidity of modern revolutions is explained by quick methods of publicity, and the slight resistance and ease with which some governments have been overturned is surprising, indicating blind confidence and inability to foresee. 10. Governments sometimes have fallen so easily that they are said to have committed suicide. 11. Revolutionary organizations are impulsive, though often timid, and are influenced by a few leaders, who may cause them to act contrary to the wishes of the majority. Thus royal assemblies have destroyed empires and humanitarian legislatures have permitted massacres. 12. When all social restraints are abandoned, and instinctive impulses are allowed full sway, there is danger of return to barbarianism. For the ancestral ego (inherent in everyone) is let loose. 13. A country will prosper in proportion that the really superior persons rule, and this superiority is both moral and mental. 14. If certain social tendencies appear to lower the power of mind, they, nevertheless, may lessen injustice to the weaker classes; and if it be a choice between mentality and morality, morality should be preferred. 15. A financial aristocracy does not promote much jealousy in those who hope to form a part of it in the future.