That theory, of course, came during the beginning of Greek philosophers so it's a little bit dated, but if you read the book, it explains a lot of theories like that in the point of view of different philosophers throughout history.

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Drama kids are cool.
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Churchill Lancers rock the Casbah...
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Sometimes you have to get to know someone really well to realize you're really strangers.
-Mary Tyler Moore

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The greatest thing you'll ever learn is just to love and be loved in return. ~ Moulin Rouge