William Shakespeare wrote Macbeth to please the people who were watching the play at the time. He incorporated several aspects of the supersitions and beliefs of the people into his play. These include, but are not limited to ghosts and witches. Many people in the 16th and 17th Century greatly believed in the existance of the super natural. Therefore, he wrote Macbeth to keep the interest of people watching his plays by basing his play on the supernatural which many were concerned and interested in.