Jonathan Lethem has an inspired essay on plagiarism and artistic creation in Harper's called "The Ecstasy of Influence." He writes:

appropriation, mimicry, quotation, allusion, and sublimated collaboration consist of a kind of sine qua non of the creative act, cutting across all forms and genres in the realm of cultural production.

and

industries of cultural capital, who profit not from creating but from distributing, see the sale of culture as a zero-sum game. The piano-roll publishers fear the record companies, who fear the cassette-tape manufacturers, who fear the online vendors, who fear whoever else is next in line to profit most quickly from the intangible and infinitely reproducible fruits of an artist's labor. It has been the same in every industry and with every technological innovation. Jack Valenti, speaking for the MPAA: “I say to you that the VCR is to the American film producer and the American public as the Boston Strangler is to the woman home alone.”

and

Artists and their surrogates who fall into the trap of seeking recompense for every possible second use end up attacking their own best audience members for the crime of exalting and enshrining their work.

and

Kenneth Koch once said, “I'm a writer who likes to be influenced.” It was a charming confession, and a rare one. For so many artists, the act of creativity is intended as a Napoleonic imposition of one's uniqueness upon the universe—après moi le déluge of copycats! And for every James Joyce or Woody Guthrie or Martin Luther King Jr., or Walt Disney, who gathered a constellation of voices in his work, there may seem to be some corporation or literary estate eager to stopper the bottle: cultural debts flow in, but they don't flow out. We might call this tendency “source hypocrisy.” Or we could name it after the most pernicious source hypocrites of all time: Disnial.

and

Any text is woven entirely with citations, references, echoes, cultural languages, which cut across it through and through in a vast stereophony. The citations that go to make up a text are anonymous, untraceable, and yet already read; they are quotations without inverted commas. The kernel, the soul—let us go further and say the substance, the bulk, the actual and valuable material of all human utterances—is plagiarism.

The essay is itself a tour de force of literary sampling. Don't skip the ending.

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