Barthes in "Authors and Writers" and Foucault in "What is an Author" both give a mixed definition of what an author is and should be. They first set up an author as a person who loses both himself and the world in his creation of a text, and then they define him as someone who takes responsibility for this very text.
Barthes, true to the title of his essay, defines his conception of an author by contrasting it with his conception of a writer. A writer is someone with a goal who uses language to convey his ideas, ignoring the properties of that language. "He does not admit that his message is reflexive"and that we can read into it, diacritically, anything else but what he means" (Barthes 189-190). An author, on the other hand, is almost the polar opposite. Not only does he use language for its own sake, but his language specifically "inaugurates an ambiguity," answering no questions, concluding no goals. Beyond this, where the text of the writer exists to fulfill the wishes of the writer himself, it seems that the text of the author exists separate from the author himself, and, in fact, consumes him. Barthes claims that "the author is the only man, by definition, to lose his own structure and that of the world in the structure of language"hence, it can never explain the world" (187.)
Foucault, as well, mentions this loss of the author and the world to the text. Contemporary writing, he says, "is primarily concerned with creating an opening where the writing subject endlessly disappears" (Foucault 116.) Also, he speaks of the "kinship between writing and death" (116), which in modern day has become "a voluntary obliteration of the self" the total effacement of the individual characteristics of the writer" (117).
Amusingly enough, however, is that both Barthes and Foucault after setting up their authors as vessels for the expression of text, who, as they focus on language itself and greater philosophical questions, remove themselves and the world they know from writing include in their definition of an author the need to take responsibility within society for the written text. Barthes speaks of writers as people who must work through other institutions to propose their thought (Barthes 190), while authors are at society's mercy, to be exalted or ridiculed (189) and in this vein, Barthes asks that the author be "responsible" (188).
Foucault mentions that texts only needed the author's name once they became open to criticism, which would result in the "punishment" (Foucault 124) of the author, requiring that a specific person take responsibility for the text he has written. Slipping into Barthes' definitions of the words, he makes the distinction that "an anonymous poster attached to a wall may have a writer, but he cannot be an author" (124). Foucault continues by noting that a scientific works which are similar to Barthes' definition of a writer's texts, in that both propose ideas independent of the language in which they are written are "accepted on their own merits and positioned within an anonymous and coherent conceptual system of established truths and methods of verification" (126). By contrast, a literary work or, in Barthes' terms, an author's text must state "its author and the date, place, and circumstances of its writing" (126) to have meaning and value.
So, though Barthes and Foucault expect an author to be lost in his text, they also expect him to step outside of his writing and take responsibility for it, both by attaching a name and by suffering society's criticisms.