The flexible element in any society, that which is susceptible of progress or decadence, must therefore be looked for rather in the physical and psychical conditions affecting the life of its component units, than in their inherited constitution. This last rather supplies a limit to variations than an element which does itself vary: though from this point of view its importance is capital. I at least find it quite impossible to believe that any attempt to provide widely different races with an identical environment, political, religious, educational, what you will, can ever make them alike. They have been different and unequal since history began; different and unequal they are destined to remain through future periods of comparable duration. But though the advance of each community is thus limited by its inherited aptitudes, I do not suppose that those limits have ever been reached by its unaided efforts. In the cases where a forward movement has died away, the pause must in part be due to arrested development in the variable, not to a fixed resistance in the unchanging factor of national character. Either external conditions are unfavourable; or the sentiments, customs and beliefs which make society possible have hardened into shapes which make its further self-development impossible; or through mere weariness of spirit the community resigns itself to a contented, or perhaps a discontented, stagnation; or it shatters itself in pursuit of impossible ideals, or for other and obscurer reasons, flags in its endeavours, and falls short of possible achievement.