"The struggle between the various species does not arise from a feeling of mutual antipathy but rather from hunger and love. In both cases Nature looks on calmly and is even pleased with what happens. The struggle for the daily livelihood leaves behind in the ruck everything that is weak or diseased or wavering; while the fight of the male to possess the female gives to the strongest the right, or at least, the possibility to propagate its kind. And this struggle is a means of furthering the health and powers of resistance in the species. Thus it is one of the causes underlying the process of development towards a higher quality of being."