optioned by another company for a television series or a video game. An author may also not have rights when working under contract that they would otherwise have, such as when creating a work for hire (e.g., hired to write a city tour guide by a municipal government that totally owns the copyright to the finished work), or when writing material using intellectual property owned by others (such as when writing a novel or screenplay that is a new installment in an already established media franchise). Philosophical views of the nature of authorship In literary theory, critics find complications in the term author beyond what constitutes authorship in a legal setting. In the wake of postmodern literature, critics such as Roland Barthes and Michel Foucault have examined the role and relevance of authorship to the meaning or interpretation of a text. Barthes challenges the idea that a text can be attributed to any single author. He writes, in his essay "Death of the Author" (1968), that "it is language which speaks, not the author." The words and language of a text itself determine and expose meaning for Barthes, and not someone possessing legal responsibility for the process of its production. Every line of written text is a mere reflection of references from any of a multitude of traditions, or, as Barthes puts it, "the text is a tissue of quotations drawn from the innumerable centers of culture"; it is never original. With this, the perspective of the author is removed from the text, and the limits formerly imposed by the idea of one authorial voice, one ultimate and universal meaning, are destroyed. The explanation and meaning of a work does not have to be sought in the one who produced it, "as if it were always in the end, through the more or less transparent allegory of the fiction, the voice of a single person, the author 'confiding' in us." The psyche, culture, fanaticism of an author can be disregarded when interpreting a text, because the words are rich enough themselves with all of the traditions of language. To expose meanings in a written work without appealing to the celebrity of an author, their tastes, passions, vices, is, to Barthes, to allow language to speak, rather than author. Michel Foucault argues in his essay "What is an author?" (1969) that all authors are writers, but not all writers are authors.