It has been commonly accepted for some time now that certain scenes in Shakespeare's Macbeth are interpolations from the writing of another author; act III, scene 5, and parts of act IV, scene 1, have been determined to be the writing of one of his contemporaries, Thomas Middleton. This can be regarded as both illuminating and problematic, depending upon how the play is being studied. It allows us to infer a great deal about the conventions and practices of writing for the stage at the time. For example, playwriting may have been more collaborative than previously thought, or perhaps Elizabethan notions of plagiarism were different from ours. While historically significant, this does complicate our interpretation of the characters in the play. It is more difficult to assess authorial intention with regard to a character's motives if the text has been redacted by multiple authors.