As the great Indian poet Rabindranath Tagore said, "Men are cruel, but Man is kind." And as the great Russian anarchist Mikhail Bakunin said, "Man is not only the most individual being on earth; he is also the most social being."
Put the two together, and it is clear that if left to its own devices, humans would "truck, barter, and exchange" (Adam Smith) to their mutual advantage, easily fending off the bad seeds among them at any given time.
Give them the means to join forces, however — i.e., provide them with territorial monopolies on the use of force, aka, nation-states — and the bad seeds metastasize into a cancer that will eventually kill its host.