这是西方人对这两种行为的态度：
Plagiarism is defined in dictionaries as the "wrongful appropriation," "close imitation," or "purloining and publication" of another author's "language, thoughts, ideas, or expressions," and the representation of them as one's own original work,[1][2] but the notion remains problematic with nebulous boundaries.[3]
A ghostwriter is a professional writer who is paid to write books, articles, stories, reports, or other texts that are officially credited to another person. Celebrities, executives, and political leaders often hire ghostwriters to draft or edit autobiographies, magazine articles, or other written material. In music, ghostwriters are used in film score composition, as well as for writing songs and lyrics for popular music genres.
http://en.wikipedia.org/wiki/Ghostwriter
http://en.wikipedia.org/wiki/Plagiarism