Were an opinion a personal possession of no value except to the owner; if to be obstructed in the enjoyment of it were simply a private injury, it would make some difference whether the injury was inflicted only on a few persons or on many. But the peculiar evil of silencing the expression of an opinion is, that it is robbing the human race; posterity as well as the existing generation; those who dissent from the opinion, still more than those who hold it. If the opinion is right, they are deprived of the opportunity of exchanging error for truth: if wrong, they lose, what is almost as great a benefit, the clearer perception and livelier impression of truth, produced by its collision with error.
John Stuart Mill
On Liberty, Ch. II
At the PhD course last week, I attributed this idea to Christopher Hitchens, hastily adding that it no doubt was not his own. I had forgotten that Hitchens himself had already attributed it to no less than three individuals, one of them, of course, being John Stuart Mill. By this oversight, I robbed my audience of an important reference point in the discussion of freedom of speech. Ironically, I was using it as an analogy for my defence of proper citation in academic writing.
"It is not just the right of the person who speaks to be heard," says Hitchens (at 2:19); "it is the right of everyone in the audience to listen and to hear."
My application of this idea runs as follows. Plagiarism is often seen as an act of "theft", i.e., a violation of the property rights of authors. There are two immediate problems with this view. The first is that it seems to grant the possibility of getting permission to plagiarize. One could, for example, simply pay the original authors for the right to pretend their words are your own. The second is that the "postmodern conditions" of today's academy make moral* claims to "intellectual property" increasingly untenable. Many of the authors I work with, for example, are essentially anarchists or socialists, and this especially when it comes to the "marketplace of ideas". My stock answer to this is to see "the moral right to be identified as the author of a work" as more like "personal" property, which anarchists generally allow, than "private" property.
How can I give my insistence on proper citation more general force? By borrowing the language of Mill and Hitchens: The peculiar evil of failing to cite an author is that it is robbing the human race; posterity as well as the existing generation. What is violated is not just the right of the author to be identified as the source of the words or ideas in question; when you plagiarize, you violate the right of the reader to know where those words or ideas came from.