Shakespeare’s speaker likens his romantic mistakes to a twisted kind of health regimen. Just as we sometimes eat sharp or spicy foods to whet a dull appetite, or take purgatives to ward off sickness before it comes, he introduced bitter experiences into a love that was already rich and satisfying. Though full of his partner’s “ne’er-cloying sweetness,” he deliberately turned to “bitter sauces”—perhaps infidelities or emotional distance—fearing that without them, desire might go stale. He made himself sick when he was actually well, a misguided policy that created real faults where none existed. The result is rueful and quietly devastating: the medicine poisoned the healthy state it meant to protect. That final couplet drives the irony home, admitting that the very drugs he used to cure a love-sickness he didn’t have ended up destroying him, precisely because he was already so deeply in love.
Sonnet 118: Like as, to make our appetite more keen — Summary
Like as, to make our appetite more keen, With eager compounds we our palate urge; As, to prevent our maladies unseen, We sicken to shun sickness when we purge; Even so, being full of your ne'er-cloying sweetness, To bitter sauces did I frame my feeding; And, sick of welfare, found a kind of meetness To be diseas'd, ere that there was true needing. Thus policy in love, to anticipate The ills that were not, grew to faults assur'd, And brought to medicine a healthful state Which, rank of goodness, would by ill be cur'd; But thence I learn and find the lesson true, Drugs poison him that so fell sick of you.