Which play by William Shakespeare contains the line, "We are such stuff as dreams are made on, and our little life is rounded with a sleep."?

This is a line from Act Four from the play, The Tempest, by William Shakespeare. It spoken by the magician Prospero to Ferdinand. Here we are told that Prospero's statement represents a place where dreams and reality mix. This quote tells us that we ultimately derive meaning in our lives from our dreams and imaginations.

As in Shakespeare's other play, A Midsummer Nights Dream or even As You Like It, dreams and reality in The Tempest come together to define how the characters in the play should live their lives. It seems that the true meaning of how a person's life should be lived isn't found in one's waking hours but rather in his or her sleep.

Most people, we are told, find that life is fragile. It's like a dream—here one minute, gone the next. It is good when people are careful and take care of life. Most people never know how or when life will end. When as humans we go to sleep, there is no guaranty that we will ever wake up. Shouldn't life always be lived in the best manner possible?