The quote in this instance is from a tragic Shakespearean play whose beauty and pathos is universal. The characters are fully realized human beings, with their own names, personalities, and ways of looking at the world. Here in "Othello" by William Shakespeare, we have a story concentrating on revenge, love, and despair in the final dramatic scene.
At the end of this tragedy, there is murder in the marriage bed, followed immediately by revelation and grief. In Act V, Scene II, the following happens. Othello enters his bedchamber where his wife Desdemona is asleep. A light is burning. Othello takes off his sword. He then becomes absorbed in a soliloquy; the abruptness of this one makes it truly mysterious. Nonetheless, its meaning has been said to contain the following:
I am here (says Othello in his mind). I am overwhelmed with horror and dread. What is the reason for my mental uneasiness (anxiety)? Is it want of resolution to do required justice? Is it the dread of personally killing (murdering) another person? No, it is not the action that is shocking. For Othello, " It is the cause, it is the cause, my soul, let me not name it to you, you chaste stars! It is the cause." Othello murders his wife alone, face to face, by strangulation, struggling with his love for her to the end.