Shakespeare's Sonnets: VII

Diverting somewhat from the theme of having children to carry on, Shakespeare here likens youth and old age to the rising and setting of the sun. The rising sun climbs through the sky (youth) until it reaches the zenith and then begins to fade until it dips below the horizon (old age). At the end, though, the poet reiterates that the sun or the youth will be forgotten if there aren’t progeny. 

Sonnet VII

Lo! in the orient when the gracious light

Lifts up his burning head, each under eye

Doth homage to his new-appearing sight,

Serving with looks his sacred majesty;

And having climbed the steep-up heavenly hill,

Resembling strong youth in his middle age,

Yet mortal looks adore his beauty still,

Attending on his golden pilgrimage:

But when from highmost pitch, with weary car,

Like feeble age, he reeleth from the day,

The eyes, ‘fore duteous, now converted are

From his low tract, and look another way:

                So thou, thyself outgoing in thy noon

                Unlooked on diest unless thou get a son.