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In Shakespeare's Hamlet, the Bard makes the characters come alive because we can empathize with what makes them human, but also allows us to observe the very things that we see (as readers) as problematic, which cause a great deal of difficulty (even death) in the play.
Ophelia is one such character, and a modern audience—even more than an Elizabethan one—can empathize with her situation. Ophelia is a dutiful daughter. Without a mother, she is ordered about not only by her father, but also her brother and (more seriously) her king.
In Act One, both Ophelia's father and brother tell her to stay away from Hamlet. Neither considers her feelings, and she has little choice as an Elizabethan woman other than to do what the men in her family tell her. Laertes, as he leaves the castle, tells Ophelia that Hamlet is not serious about her, and that she should assume he is just having his fun:
For Hamlet, and the trifling of his favours,
Hold it a fashion, and a toy in blood… (I.iii.6-7)
He also tells his sister that Hamlet is not free to love anyone he wants, but must choose a wife in keeping with his title of prince:
His greatness weigh'd, his will is not his own;
For he himself is subject to his birth. (20-21)
When Polonius questions his daughter about what Laertes had to say, she explains that her brother offered up concerns about her relationship with Hamlet. Echoing her brother's words, though more harshly, Polonius also notes that she is foolish to believe what Hamlet says, or to pay special attention to the gifts he gives her:
Think that you are a baby,
That you have taken these offers for true love,
Which are not true offers. Consider yourself more dearly... (111-113)
Polonius tells Ophelia that she is inexperienced. She should value herself more and keep her distance from the prince, or Polonius infers she will embarrass him by getting pregnant.
Laertes may seem somewhat concerned for her, but he leaves anyway. Polonius is strongly opposed to Hamlet and especially concerned about his position in the court; he does not worry that Ophelia may suffer—only that her actions would reflect badly upon him!
When Hamlet begins (by design) to act crazy, Polonius offers the King his daughter's assistance in spying on Hamlet to see what is ailing Hamlet. Claudius (and even Gertrude) agrees to this subterfuge. Secretly, Claudius is not sure what to make of Hamlet: is he a threat? Gertrude is worried about Hamlet, aware that her swift remarriage to Claudius (so soon after her husband's death) may be the cause of Hamlet's distress.
In many ways, Ophelia is a victim to her society. She depends upon the men in her life to survive. Neither her family nor the King worries about her. And whereas Hamlet should, he does not. He is aware that Ophelia is spying on him. She does so without malice: she does not want to see him hurt, and is truly worried for him. But she never once takes her worries to Hamlet. This is a problem. If they have been sweethearts, she should be able to tell him everything! She might also have asked for his help. However, in failing to do so, she becomes a pawn of both sides: she is used for information on one hand; she is insulted and berated by Hamlet, who is so blinded, he has no sympathy for her. Ultimately, she loses her father, Hamlet's love, her mind, and her life.