What did Karl Marx mean by "the movement of this antithesis"? In a lecture about ancient and modern cities, a quote came up on the slides from Karl Marx's Capital where he writes


  "The foundation of every division of labor that is well developed, and brought about by the exchange of commodities, is the separation between town and country. It may be said that the whole economic history of society is summed up in the movement of this antithesis."


What does a movement of an antithesis mean ? And I don't understand what antithesis he is referring to in this excerpt; what is being contrasted; the well-established separation of divisions of labour and the exchange of their resulting specialised products ? Or the well-established foundations of divided labour and how that was brought about by exchanging commodities (or that commodities could be exchanged at all) ? Or am I missing something else completely ? Is this a translation thing, an English thing or an economics thing ?
Town represents manufacturing and it's where a lot exchanges taking place. Country represents farming. The movement of antithesis symbolizes the urbanization of civilizations as economy progresses.

As an economy progresses, people will move from rural area into the cities. Labour associated with agriculture will decrease, at the same time, workforce in manufacturing and services industries will increase.