A first-person poetic persona compares people to restless clouds. Clouds speed brightly across the sky but disappear at night, presumably like a human life. The persona then compares people to lyres, stringed instruments, that are always playing different tunes based on different experiences. The persona then complains that whether we are asleep or awake, a bad dream or a “wandering thought” interferes with our happiness. Whatever we think, however we feel, “It is the same,” meaning that all will pass away and people will change. Thus, the one thing that endures is “Mutability.”
In typical Romantic fashion, Shelley immediately places humans in the same physical realm as nature, opening with “We are as clouds.” Immediately following, however, Shelley focuses on human agency and compares humans to things invented, this time using the simile “like forgotten lyres.” (A lyre is a musical instrument, a Greek wind harp.) The purpose of the two comparisons is to emphasize the eternal human condition of change, in other words, to be mutable. This is both a natural condition, such as the clouds that are one minute here and the next minute there, “restlessly speeding, gleaming, quivering, and streaking across the dark night” only to be soon thereafter “lost for ever,” on the one hand, and a human-caused phenomenon, such as a lyre, “whose strings give a various response to various blasts” and on which no new “modulation sounds like the last.” The point is that all things, natural or created, are always changing. Nothing is constant.
We can recognize early on that the poetic form of “Mutability” is a lyric, a poem that is “brief and discontinuous, emphasizing sound and pictorial imagery rather than narrative or dramatic movement” (Frye 268). In “lyrical poetry” generally, the poet is speaking to himself, musing, or asking rhetorical questions to an unknown third party, not necessarily addressing the reader. Finally, the lyric usually takes the form of the rhyming couplet, with an abab cdcd efef ... pattern, just as Shelley does here (moon/quiver/soon/ever ...). Shelley uses the similes to draw us into the natural and artificial worlds (“We are as clouds”; “Or like forgotten lyres). This poetic technique is quite common among Romantic poets. Romantics both before Shelley (such as Wordsworth and Coleridge) and after him (Keats) used the same lyrical style and imagery with natural similes to describe people’s place in the universe.
In the third stanza, Shelley introduces a third dimension to his argument—human thought and emotion. Whether our thoughts occur during sleep (“we rest”) or while we are awake (“we rise”), our thoughts, too, are forever changing. Change is not good or bad for its own sake; Shelley notes that a dream has the “power to poison our sleep” just as “a wandering thought pollutes the day,” yet our thoughts and emotions also can lead us to “laugh” or “cast our cares away.” In some of these mental states, we have no control over the forever changing mutability of our mind, but in others, we make our own change.
In the final stanza, Shelley makes thoughts and emotions “free,” suggesting a political dimension to the poem. It helps to keep in mind the historical context of the poem. The French Revolution was probably the most significant event to hit Europe in over one hundred years. Not only did it change the political contours of Europe, but it also led European societies outside of France to re-evaluate their own political systems, and it inspired interest in overcoming tyranny. Shelley chooses to rhyme “morrow” with “sorrow,” suggesting that despite the sorrows of today, there will be a brighter future tomorrow, for all things do eventually change: “Man’s yesterday may ne’er be like his morrow.” In this sense, in politics just as within a person’s own mind, looking for eternal stasis and sustainability is a lost cause.
Another way to analyze “Mutability” is to look at what Shelley is suggesting about the human condition of narcissism and vanity. The first stanza suggests the theme of ‘out of sight, out of mind,’ since the clouds are “lost forever” once they pass out of our sight. Similarly, notice how the lyre is “forgotten.” If nobody is playing it, the sound is gone and the instrument is forgotten. This has sometimes been interpreted as Shelley saying that people are only as real and “responsive” as the musician who plays us, in other words susceptible to some higher being who toys with our “strings” (compare Shakespeare’s Hamlet: “Do you think I am easier to be play’d upon than a pipe? Call me what instrument you will, thou you fret me, you cannot play upon me,” III.ii.369-72). Yet, we humans play on our own strings and on one another’s strings, so no higher power need be invoked here. The point is that like clouds and instruments, people are easily forgotten when they stop making change or doing anything significant in the world—especially once they die and pass away into night.
The tone, mood, and point of view in Mutability are up for debate. While some find the speaker to be pessimistic about change, focusing on the way it interrupts what is good (like the excesses of the French Revolution), others find the speaker optimistic, coming to terms with the forever changing state of the universe and finding the human ability at least to make sense of a world that changes.