Consider one or two examples of ideas that have played dominant rôles in the lives of nations. They are mostly political, or religious, or, most powerful of all, politico-religious. The idea of world-conquest has dominated and has destroyed several great nations, of which the latest example is the German Empire. The idea of conversion by the sword, accepted with enthusiasm by the Arab nation, gave it for a time tremendous energy, but contained no potency of permanent power or of progress. The idea of immortality, or desire of continued existence after death, seems to have dominated the minds of the ancient Egyptian people; the idea of escape from the evils of this world, those who have fully accepted Buddhism, like the Burmans[98]. The idea of caste as an eternal and impassable barrier has largely determined the history of India. All these are ideas which have proved ineffective to sustain national vigour or to promote social evolution. It would not be strictly true to say that the fall, or the unprogressive condition, of the peoples that have entertained these ideas is the result of those ideas; because the general acceptance of them proves that they were in harmony with the type of mind of the people. Yet the formulation of the ideas by the leading minds who impressed them on the peoples must have accentuated those tendencies with which they harmonised; and in each case, if the idea had never been formulated, or if others had been effectively impressed on the mind of the people, the course of its history would have been changed. Of ideas less adverse to national life take the idea of ancestor worship, and the idea of personal loyalty to the ruler, ideas which commonly go together and have played an immense part in the life of some peoples, notably in Japan; they have served as effective national bonds in periods of transition through which despotically ruled populations have progressed to true nationhood. The idea of the divine right of kings played for a time a similar rôle in Europe.