https://www.coursehero.com/lit/Sonnets-of-Shakespeare/sonnet-18-summary/
Sonnet 18
The speaker begins this Petrarchan sonnet by asking rhetorically if he should compare the subject to a summer's day. He asserts that there would be no point in doing so because the subject is superior in many ways: his beauty is more mild, temperate, and long-lasting. His beauty will never diminish because he will live on into the future in this sonnet.
1.
Narrator, Sonnet 18
So long as men can breathe or eyes can see, / So long lives this, and this gives life to thee.
Narrator, Sonnet 18
The final couplet of Sonnet 18 expresses a sentiment found a number of times throughout the sonnets: that it is through the power of art, specifically this sonnet, that the beauty of the subject, the fair youth, will live on despite the destructive march of time. A consistent theme underlying this sentiment is that, as much as the poet admires his subject, he transcends him in his power to immortalize.
