A specific example of this appears in the last line of the second section of The Waste Land, "A Game of Chess", "Good night, ladies, good night, sweet ladies, good night, good night." It is taken directly from Hamlet 4.5.111-112. This is Ophelia's line, spoken at the height of her madness, not long before her death.  It is not her final exit, but the scene makes clear that due to the murder of her father by her lover she is no longer in complete possession of her sanity.  What does Eliot mean to do by using these exact words?  I doubt that he thought them merely to be suitably poetic for his purposes. Then, if not only using the line for the sake of using a well known line in a well known story, what does he mean to do?  Does he wish to call to the reader's mind the plot of Hamlet, that specific scene, Ophelia's betrayal by her lover, or possibly everything that Ophelia has come to embody after centuries of analysis?  By this, I am referring to the number of interpretations various critics have applied to her throughout the centuries, including that of post-modern feminist symbol (how many recent books or songs written by women have used "Ophelia" in their title?).  Taken as the ending of a section of the poem largely dedicated to the futility and sterility of love, both of the high and of the low (a theme reoccurring throughout), it can be seen as an emphatic conclusion.  Another look may reveal it as supporting the theme of women driven across the normal lines of existence as a result of love.  A third interpretation may focus on the oppression of women by those who are supposed to love them.  Here we see one of the dangers of interpreting poetry written over seventy years ago.  We may be inclined to bring in the most recent ideas on subjects Eliot alludes to, but in doing so we risk distorting his intent.  How likely is it that the elitist Eliot, whose misogyny is all too often strikingly clear, was using the feminist's version of Ophelia to make a statement about the condition of women?  By using a line from Hamlet, it seems to me that Eliot has added another dimension to his poem and called to mind a host of other ideas through just a few lines.