Shakespeare begins his sonnets by introducing four of his most important themes — immortality, time, procreation, and selfishness — which are interrelated in this first sonnet both thematically and through the use of images associated with business or commerce.
The sonnet's first four lines relate all of these important themes. Individually, each of these four lines addresses a separate issue. Line 1 concerns procreation, especially in the phrase "we desire increase"; line 2 hints at immortality in the phrase "might never die"; line 3 presents the theme of time's unceasing progress; and line 4 combines all three concerns: A "tender heir" represents immortality for parents, who will grow old and die. According to the sonnet's poet, procreating ensures that our names will be carried on by our children. If we do not have children, however, our names will die when we do.
But, the scenario the poet creates in these four lines apparently has been rejected by the young man, whom the poet addresses as "thou," in lines 5–12. Interested only in his own selfish desires, the youth is the embodiment of narcissism, a destructively excessive love of oneself. The poet makes clear that the youth's self-love is unhealthy, not only for himself but for the entire world. Because the young man does not share himself with the world by having a child to carry on his beauty, he creates "a famine where abundance lies" and cruelly hurts himself. The "bud" in line 11 recalls the "rose" from line 2: The rose as an image of perfection underscores the immaturity of the young man, who is only a bud, still imperfect because he has not fully bloomed.
The final couplet — the last two lines — reinforces the injustice of the youth's not sharing his beauty with the world. The "famine" that he creates for himself is furthered in the phrase "To eat the world's due," as though the youth has the responsibility and the world has the right to expect the young man to father a child. Throughout the sonnets, Shakespeare draws his imagery from everyday life in the world around him. In Sonnet 1, he writes of love in terms of commercial usury, the practice of charging exorbitant interest on money lent. For example, in the first line, which reads, "From fairest creatures we desire increase," "increase" means not only nature's gain through procreation but also commercial profit, an idea linked to another trade term, "contracted," in line 5. In line 12, by using the now-antiquated term "niggarding," which means hoarding, the poet implies that the youth, instead of marrying a woman and having children, is selfishly wasting his love all for himself.
