In Sonnet 11, Nature carves a young man as her seal
Sonnet 11 imagines a person as a printing stamp. Nature, Shakespeare says, cut this young man as her personal seal, meaning him to press out copies rather than let the original vanish. Along the way the poem runs a grim thought experiment: if everyone refused children, humanity would be gone within sixty years.
The opening is a neat piece of arithmetic. However quickly the young man declines, a child of his would grow at the same rate, so what he loses to age he regains in his offspring. The young blood he passes on while still youthful is something he could call his own once he himself has left youth behind. Decline and renewal are set side by side as two halves of one transaction.
Lines five to eight widen the stakes. Wisdom, beauty and increase live on in this choice, the speaker argues, while the alternative brings only folly, age and cold decay. Then comes the startling scale-up: if every person thought as the friend does, time itself would stop, and "threescore year" would be enough to empty the world. A private decision is suddenly treated as a question for the species.
The third quatrain is the harshest passage in the poem. Let those whom Nature did not shape for breeding, the harsh, the featureless and the rough, die childless, the speaker says; she gave the most to those she favoured, and gave this young man more still. A generous gift, he insists, ought to be cherished generously. The couplet then delivers its image of the seal: the friend should print more impressions and not let that copy die.
Shakespeare knew large families at first hand. Of eight children he came third, and no older brother survived; he was born in Stratford-upon-Avon to John Shakespeare, a glover and alderman from Snitterfield, and Mary Arden, whose landowning family carried weight among Recusant Catholics. He was baptised on 26 April 1564; his birthday is traditionally kept on 23 April, the same date on which he died in 1616.
Source: Sonnet 11: As fast as thou shalt wane, so fast thou grow'st
