Today on The Gist, something none of us know anything about—porn. Pesca is away, but Felix Salmon from Fusion, Piper Text (and, of course, Slate Money) will be your guide. First up, we explore the difference between art and pornography with Amy Adler from New York University. Does it have anything to do with the price tag? For the Spiel, what the July 8th glitches tell us about complex systems and illusory correlation.

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