nsequently, we cansay that in our culture, the name of an author is a variable thataccompanies only certain texts to the exclusion of others: a privateletter may have a signatory, but it does not have an author; acontract can have an underwriter, but not an author; and, similarlyan anonymous poster attached to a wall may have a writer, buthe cannot be an author. In this sense, the function of an author isto characterize the existence, circulation, and operation of certaindiscourses within a society
Very useful statement of where foucault applies in this case: to literary discussion, not advertising, not letters, and so on.
Science would fall into the "not this" category, I suspect.