Is there such thing as self-plagiarism?

There has been an explosion of indignation in the publishing community this past couple of days as Jonah Lehrer, a popular neuroscience writer, has been caught “self-plagiarising” his own work. Lehrer himself has apologised but not everyone is so upset. Is it ureasonable to rework old columns with partially duplicated content and brush up the cream of the crop in to a best-selling book, as Lehrer has? Is this not the natural evolution of ideas? For some like myself, the primary reason for writing is to allow our ideas to evolve. We place our ideas out to tender, listen to the feedback, scrap the bad ones and maintain and improve upon the good ones. If we feel we can not improve upon how an idea is phrased, should we be obliged to arbitrarily reword it if we wish to build upon it or repeat it to a new audience?

Lehrer has clearly been foolish to think he can get away with repeating whole paragraphs from one column to the next without at least informing his publisher, the New Yorker. At the same time, if you have taken time and effort crafting words in to an idea until you feel it can not be improved upon, do we really care if when this idea comes up again, the same words are pulled back out of the hat? The way many writers see things is that blogs are works in progress, with a book representing somewhat more of a final product. It seems to me that Lehrer was wrong to fail to tell the publishers of his column (the New Yorker) that he was partially reusing his own content with only a cursory attempt to re-jig it, but is this really a hanging offense? If this was an article in a scientific journal this would be a different matter, scientific journals are for new science. The popular press on the other hand is supposed to be where we can craft and share our thoughts openly, good ideas can be missed, they can also be repeated, different outlets have different audiences. There are columnists at the Daily Mail for example, that bang the same hate filled drum, day in day out in a million different ways (often, unlike Lehrer, without even the slightest care to reference I might add). Are we to say that (assuming self-plagiarism exists) this is not self-plagiarism, just because the words are in a slightly different order each day. The habit is certainly poor form, but to suggest (as some have at very great length) that it was a crime for him to keep the odd passage as he consolidated his work in to a book, seems beyond barmy. Applying the concept of plagiarism, a serious offence for writers, to the writer himself seems similar to confusing rape with masturbation. One is a heinous crime that should not be taken lightly (and by referencing it here, this is certainly not my intention) and the other is a minor embarrassment, but an embarrassment that is only human. In fact, that joke was self-plagiarised, I made it at 4.54PM today on twitter where it would have received little exposure because most people would have been preparing to walk out of the door from work. If I repeat it without first acknowledging that I have said that sentence in the past, is this now self-plagiarism? It probably shouldn’t be repeated because it was a bad joke in bad taste, but to suggest the line should be arbitrarily reworded, just to stop it becoming a case of self-plagiarism seems to me at least, to be a bizarre logic.