Plagiarism

When Lethem talks about how important "plagiarism" is to the furthering of the arts, he defines the term quite loosely as anything that is using somebody else's material in your own work. This passage about Bob Dylan's lyrics exemplifies that:
"Dylan's art offers a paradox: while it famously urges us not to look back it also encodes a knowledge of past sources that might otherwise have little home in contemporary culture, like Civil War poetry  of the Confederate bard Henry Timrod, resuscitated in lyrics on Dylan's newest record, Modern Times. Dylan's originality and his appropriations are as one" (Lethem, 212).
While Lethem equates plagiarism to appropriations in the arts, Rutgers defines it as simply not giving credit where credit is due. Using somebody else's idea, or even writing, is considered plagiarism but reusing things in the public domain and building on them is not. Lethem talks about plagiarising things that probably shouldn't be considered property in the first place because are ideas and that reflect emotion and not concrete products.