There is probably not one bar of music existing that had not been composed before, and not one sentence in any language that was not previously published. Listen to "Hatikva," and you can find the basic melody in a work by Borodin. The music of the 1950s hit song "Stranger in Paradise," from the musical Kismet, is straight out of Verdi's opera Aida, and there are other popular songs based on passages in Gustav Holst's The Planets Suite. Even the classical composers influenced each other's work, and there were many feuds among the great masters. (There is also some question as to whether Charles Lamb, and not Shakespeare, really wrote all those incredible plays and sonnets.) J.R. Rowling confesses that her Harry Potter saga was created after a childhood of reading C.S. Lewis's Narnia and Tolkien's Rings series. In fact she did those writers a favor because the worldwide Harry Potter mania has reawakened interest in those earlier magical characters. However, Rowling vehemently denies having stolen the term "Muggles" from an earlier book written in the Thirties, and in fact won her case in court. Dan Brown is still fighting accusations that his Da Vinci Code was based on a nonfiction historical book written several years before his novel became a best-seller. So what is the difference between publishing work that is influenced by previous works of literature or music and actually committing plagiarism? ACCORDING TO Webster's dictionary, plagiarism is "the unauthorized use of or close imitation of language/thoughts of another author and representation of them as one's own original work." The copyright laws of Europe protect the author for his lifetime and for 70 years after his death or posthumous publication. According to the Writers and Artists Year Book produced by the London publishers A.C. Black, "quotes from published works can only be used with permission, unless it is a review or critique of that work and even then, not more than 400 words can be quoted. Or, alternatively, separate extracts of not more than 300 words can be used, totalling not more than 800 words in all." However, the copyright laws do not completely reflect the definition of plagiarism, for ideas and information cannot be copyrighted unless the author is the originator of specific research. Therefore if an author comes forward and says that a successful new novel is a plagiarism of the theme of his own book, which may be lying unsold in numbers on some dusty shelf - while it may be infuriatingly frustrating for him - it is in fact very difficult to prove. IN THE SAME way, titles are not copyrighted, but using the title of a book already in print can do irreparable damage, as happened to this writer. In the mid-Nineties, my own book, Life After Birth - Everywoman's Experiences of the First Year of Motherhood, was published by a small independent publisher in Britain. As I am a professional counselor working in this field the book was a serious look at the year after childbirth and how parents connect the fantasies of pregnancy, the birth experience itself and their adjustment in the following months. The targeted market was the expectant or new parent, peer counselors and health professionals working in this area. We did not expect it to hit the best-seller list, but it did well in the first two years, even being translated into Spanish. Then one of the large British publishers brought out a book also titled Life After Birth, written as a tongue-in-cheek-for-yuppies type of book, focusing more on how to find the right nanny and get out of the house. The author was a tabloid journalist, very well known in Britain, but with no actual qualifications in the maternity health professions. However, the title of the book was the same, the cover and layout were similar, and the author had used many of my own references. This large publisher promoted and sold the book far more effectively than my small independent publisher had, and the sales figures were impressive. THIS DID not so much affect my UK sales because the targeted market was very different. However, it totally destroyed the potential of getting the book translated into Hebrew because Israeli publishers make decisions on translating foreign-language books almost solely on the basis of sales figures. My own book was being considered by an Israeli publisher when this other book was rushed through the system and translated into Hebrew - even though it had no relevance whatsoever for the Israeli market and, in fact, disappeared soon after from the local bookshelves. However, as far as my book was concerned the damage was done, and my potential publisher lost interest. As a member of the British Society of Authors I sought advice from their experts and learned that even though I had suffered irreparable damage, I had no legal rights over the title and the layout. This injustice is carried through in a situation where an author sends a proposal or idea to a publication or broadcasting service, is rejected, and then greatly chagrined a year or so later to see that the idea has been used by a staff writer or other author, who was obviously commissioned to follow through the original idea. The creator of the idea does not earn a cent from this and, as a result, cannot market his idea elsewhere because it is no longer original. Sometimes it is prestige and not money at stake. When working at an academic institution in Haifa some years ago, I wrote an article for its journal, unpaid because I was on staff at that time. The editor decided to do one of his freelance journalist friends a favor, publishing it almost word-for-word under his name. He got the fee and the byline. In the current case of Naomi Ragen vs Michal Tal, there first has to be proof that Ragen was given Tal's book, The Lion and the Cross, and that as a direct result of reading it she used the basic theme in her own book, The Ghost of Hannah Mendes, changing names but nevertheless stealing actual passages exceeding 400 words. The latest claim by Sarah Shapiro that entire blocks of text from a book of hers were used in a later book by Ragen can be proved more easily if the identical wording exceeds 400 words. It is said that all publicity is good publicity. In the case of The Da Vinci Code, many previously written nonfiction books on this theme were reissued and promoted because the public's interest had been awakened by the rather implausible but page-turning work of Dan Brown. So whether or not Michal Tal and Sarah Shapiro can prove that their books were plagiarized, they are getting publicity and readers interested in the subject may indeed want to buy those books to see what they have to say. The writer, based in Haifa, is the author of Life After Birth (Element) and The Soldiers' Mother (Bibliobooks).