When a physiologist speaks now of the life of a plant or of an animal, he sees rather an agglomeration, a colony of millions of separate individuals … - Peter Kropotkin

The State is only one of the forms assumed by society in the course of history. Why then make no distinction between what is permanent and what is accidental?

Each individual is a cosmos of organs, each organ is a cosmos of cells, each cell is a cosmos of infinitely small ones; and in this complex world, the well-being of the whole depends entirely on the sum of well-being enjoyed by each of the least microscopic particles of organized matter. A whole revolution is thus produced in the philosophy of life.

In the animal world we have seen that the vast majority of species live in societies, and that they find in association the best arms for the struggle for life: understood, of course, in its wide Darwinian sense — not as a struggle for the sheer means of existence, but as a struggle against all natural conditions unfavourable to the species. The animal species, in which individual struggle has been reduced to its narrowest limits, and the practice of mutual aid has attained the greatest development, are invariably the most numerous, the most prosperous, and the most open to further progress. The mutual protection which is obtained in this case, the possibility of attaining old age and of accumulating experience, the higher intellectual development, and the further growth of sociable habits, secure the maintenance of the species, its extension, and its further progressive evolution. The unsociable species, on the contrary, are doomed to decay.