In Sonnet 18, Shakespeare uses the extended metaphor of a summer's day to which he compares his beloved. He finds her lovely and, using a double entendre, more temperate (which has two meanings—being of a milder temperature and being more even-tempered) than a day in summer. Then, using a form of personification called pathetic fallacy, he attributes human qualities to aspects of nature. For example, he says that rough winds shake the flowers of May (as if they were human) and that summer has a lease, or a duration like that of a lease on an apartment, that is too short. He also says that heaven, or the sun, shines too hot or sometimes disappears. When the sun disappears, his (the sun's) complexion is dimmed as if he were a person. These are all examples of pathetic fallacy. Later, the poet personifies Death, who stalks people in his shade. However, his beloved's "eternal summer," a metaphor for her beauty, will not disappear, as she will live forever in the poem.