Units vs systems thinking

Western civilization has a tendancy to divide things into units: people, parts, elements.  This has led to some of the greatest advances in history.  Capitalism for instance, with all its flaws, is still better than any of the alternatives.  Medicine has made huge strides forward too.  However, consider this old joke:
A urologist suggests that his patient drink less beer, perhaps replace it with spirits.
"But Doc, won't spirits damage my liver?"
"Yes, probably.  But you came to me about your kidneys, not your liver."

The point is that having separated concepts into units or elements, the challenge is to bring it all back together.  Sure cars are a great means of transportation, but they have to exist in the environment which they currently destroy.  We will never solve the problems of humanity unless we learn to see units as part of systems.

Therefore, systems comprehension needs to be part of the list of 21st century literacies that we need to teach our students..