[Footnote A: (Heraclitus of Ephesus).] The struggle for existence is, in the life of Nature, the basis of all healthy development. All existing things show themselves to be the result of contesting forces. So in the life of man the struggle is not merely the destructive, but the life-giving principle. "To supplant or to be supplanted is the essence of life," says Goethe, and the strong life gains the upper hand. The law of the stronger holds good everywhere. Those forms survive which are able to procure themselves the most favourable conditions of life, and to assert themselves in the universal economy of Nature. The weaker succumb. This struggle is regulated and restrained by the unconscious sway of biological laws and by the interplay of opposite forces. In the plant world and the animal world this process is worked out in unconscious tragedy. In the human race it is consciously carried out, and regulated by social ordinances. The man of strong will and strong intellect tries by every means to assert himself, the ambitious strive to rise, and in this effort the individual is far from being guided merely by the consciousness of right. The life-work and the life-struggle of many men are determined, doubtless, by unselfish and ideal motives, but to a far greater extent the less noble passions--craving for possessions, enjoyment and honour, envy and the thirst for revenge--determine men's actions. Still more often, perhaps, it is the need to live which brings down even natures of a higher mould into the universal struggle for existence and enjoyment. There can be no doubt on this point. The nation is made up of individuals, the State of communities. The motive which influences each member is prominent in the whole body. It is a persistent struggle for possessions, power, and sovereignty, which primarily governs the relations of one nation to another, and right is respected so far only as it is compatible with advantage. So long as there are men who have human feelings and aspirations, so long as there are nations who strive for an enlarged sphere of activity, so long will conflicting interests come into being and occasions for making war arise.