Capitalism is the limit of free exchange as the world shrinks.

When the world was large, exchanges were rare and not based entirely on specie. Effects from religious or cultural obligation to a desire to curry favor helped to find a room or a meal in a strange town.

As the world shrank exchanges multiplied, commerce and specie spread.

Two hundred years ago fifty species shared the capitalist world, then a handful sufficed, until  one; and then, there was one money and no specie behind. A piece of a dream. 

War has returned and money will fracture and become a basket if not a thing, as Marx predicted.