Sonnet 18

Summary:The speaker opens the poem with a question addressed to the beloved: “Shall I compare thee to a summer’s day?” The next eleven lines are devoted to such a comparison. In line 2, the speaker stipulates what mainly differentiates the young man from the summer’s day: he is “more lovely and more temperate.” Summer’s days tend toward extremes: they are shaken by “rough winds”; in them, the sun (“the eye of heaven”) often shines “too hot,” or too dim. And summer is fleeting: its date is too short, and it leads to the withering of autumn, as “every fair from fair sometime declines.” The final quatrain of the sonnet tells how the beloved differs from the summer in that respect: his beauty will last forever (“Thy eternal summer shall not fade...”) and never die. In the couplet, the speaker explains how the beloved’s beauty will accomplish this feat, and not perish because it is preserved in the poem, which will last forever; it will live “as long as men can breathe or eyes can see.”
THEMES:
LOVE: Sonnet 18 opens up looking an awful lot like a traditional love poem, but by the end it’s pretty clear that the poet is much more into himself and the poetry he produces than the beloved he’s addressing. In fact, at times it seems like he might actually harbor some resentment toward the beloved. So if it is a love poem, it’s to the poet.
MAN AND THE NATURAL WORLD: On one level, Sonnet 18 is clearly concerned with the relationship between man and the eventual, inescapable death he’ll encounter in nature. On another level, the poet also seems fascinated by the relationship between seasonal weather and personal, internal "weather" and balance
TIME: The speaker of Sonnet 18 is absolutely fixated on fate and mortality, but believes he’s come up with an effective time machine: poetry. Instead of contemplating a beautiful summer’s day, this speaker can’t stop thinking about how everything in life is temporary and fleeting. No need to fear, though – the hero-poet steps in and