William Shakespeare's sonnets explore a wide range of themes, including love, beauty, time, mortality, and the nature of art. In Sonnet 116, Shakespeare grapples with the nature of love and what it means to be truly in love. The poem begins by declaring that love is "not every thing that alters when it alteration finds," meaning that true love does not change or fade when faced with obstacles or challenges. The speaker goes on to describe love as "an ever-fixed mark" that is "never shaken" and "bears it out even to the edge of doom," suggesting that true love is enduring and unwavering.
Throughout the poem, the speaker seeks to define and understand the true nature of love, positing that it is not something that can be easily defined or understood. The poem suggests that love is an enduring and constant force that persists through time and is not easily swayed by external factors.
Overall, Shakespeare's Sonnet 116 explores the theme of the nature of love by attempting to define and understand this complex and multifaceted emotion. Through the use of vivid imagery and powerful language, the poem portrays love as a deeply personal and enduring force that is capable of withstanding the test of time.