This famous speech or quote from Macbeth provides an illustration of or an allusion to a famous scene or incident within the play. This important quote from Macbeth may be familiar surrounding the theme of this Shakespearean tragedy. The famous and important Macbeth quote, or soliloquy, by William Shakespeare, can often follow the theme of ambition, the supernatural, insanity, revenge, irony and madness and featured in this great literary work. We use Shakespeare's words all of the time in everyday speech, which might include a quote from Macbeth, but we are often totally unaware that we are 'borrowing' a famous saying or quotation from a Shakespearean play! The Shakespeare characters strongly featured in many a Macbeth quotation or quote are Macbeth, Lady Macbeth and the three witches.