Everything is Connected

From a book on System Theory by Donella H. Meadows. 
(2008). Thinking in Systems: A Primer. White River Junction, VT: Chelsea Green Publishing. 

"Everything, as they say, is connected to everything else, and not neatly. There is no clearly determinable boundary between the sea and the land, between sociology and anthropology, between an automobile's exhaust and your nose. There are only boundaries of words, thought, perception and social agreement – artificial, mental model boundaries.
The greatest complexities arise exactly at boundaries. There are Czechs on the German side of the border and Germans on the Czech side of the border. Forest species extend beyond the edge of the forest into the field; field species penetrate partway into the forest. Disorderly, mixed-up borders are sources of diversity and creativity". ( p.95)