Sonnet 21 from Sir Philip Sidney’s Astrophil and Stella sonnet sequence is a highly typical poem that exemplifies many of the standard themes and techniques of the sequence as a whole. In this sonnet, Astrophil is responding to the wise advice of a friend who has blamed Astrophil for allowing himself to be entangled by selfish desire (or cupiditas, associated with Cupid). The friend suggests that Astrophil has thus defaced the original God-given potential of his “young mind” (2) and also that Astrophil is misusing his “wit” (that is, his reason) by indulging in “vain thoughts” and neglecting “virtue” (4). This, of course, is precisely the opposite of how sixteenth-century Christians were expected to use the divine gift of reason.
In the second half of the octet (or eight-line opening section of the poem), Astrophil reports that his friend has told him that he is wasting his time reading Plato (a “wise pagan” who used his own gift of reason splendidly) unless Astrophil uses such reading to help tame his uncontrolled passions, which are compared to a wild horse. The friend has told Astrophil that because he was born as a human being (not an animal), and because he was born into a high position in the social structure, he is expected to display “Nobler desires” (7). In this phrase, there is a clear pun on the double meaning of “Nobler” (that is, both aristocratic and virtuous).
If Astrophil fails to display such desires, “Great Expectation,” which is his “friendly foe” (7-8), will be ashamed of him. In other words, people who genuinely care about Astrophil, such as his friends and family, will be disappointed in his unreasonable conduct, in the same way that a coach or teacher (who are “friendly foes” in the sense that they challenge us and expect us to do our best) are disappointed in athletes or students who fail to reach the true potential they possess. After all, if Astrophil has failed, in his relative youth, to reach his potential (9-10), what can be expected to happen to him when he reaches old age or death (his “harvest time” )?
In lines 12-13, Astrophil finally responds explicitly to all this good advice. He concedes that his friend’s counsel has been wise and learned. However, in the second half of line 13 and also in line 14, Astrophil neglects his friend’s wise words and returns to his obsession with Stella. This sudden switch in the final lines of a sonnet is very typical of many of the sonnets in Astrophil and Stella. Astrophil is fixated on Stella and cannot keep his mind off of her for long, even though he often admits that his obsession is self-destructive. His final question here is ironic: there may indeed be nothing as fair in “this world” as Stella, but Astrophil, as a Renaissance Christian, would have known that he was expected to keep his focus on the next world, and on God.