The speaker of "Thyrsis" is out in the Oxford countryside, the same setting as "The Scholar-Gipsy." He and his friend Thyrsis once visited this area often, and he laments how it seems to have changed so much. Where they once saw only pastoral beauty here - a vale, a path, and more - now the landscape is dotted with the city of Oxford.
He looks for an old elm-tree that they used to admire, and which they connected to the Scholar-Gipsy. They had always believed that the scholar-gipsy would survive as long as they tree was around (see summary and analysis of "The Scholar-Gipsy" for backstory).
As he laments not visiting this area often anymore, the speaker also criticizes Thyrsis for having left, "of his own will." Though he loved the area, he was drawn elsewhere, and now is dead. (The death relates to the allusion Arnold is making to Virgil - see the Analysis for more detail.) While the speaker knows his current despair might wax and wane with the seasons, Thyrsis will nevermore return.
Though Thyrsis was defeated in battle by Corydon, the speaker blames Thyrsis for his own death. Stanzas 9 and 10 recall the Sicilian tradition of playing a sad song on a pipe when a shepherd died, so that in Hades, Proserpine (Persephone) would return the dead to life. However, Arnold knows that since Proserpine has never been to England, it is futile to try and call on her.
During the next several stanzas, the speakers walks through the countryside, lamenting all he has lost since Thyrsis has gone. He recalls a girl who once helped them with their boat, and is sad to realize she has disappeared as well. During the lament, he becomes overwhelmed with the world's problems in the larger sense.
In stanzas 16 and 17, the speaker's mood brightens as he sees a group of jovial hunters ride into town. Finally, he sees the elm-tree he was searching for, which confirms that the scholar-gipsy must still be alive, on his quest for truth.
In this brighter mood, the speaker tries to mend his hateful opinions on Thyrsis. He decides that when Thyrsis left, it was not to abandon the search for truth. Instead, he was continuing to seek truth, but had to become a wanderer because the world would not allow him to search otherwise.
"Thyrsis" can be quite difficult to understand without guidance, since it is rooted both in an extended allusion to Virgil's poetry and in Arnold's own life. In Virgil's Seventh Eclogue, Thyrsis lost a singing match to Corydon, and died. Whereas Virgil implies that the gods are to blame for the man's death, Arnold alters the myth to blame Thyrsis himself.
This shift is central, and connects to the poem's autobiographical quality. Matthew Arnold wrote "Thyrsis" to commemorate the life of his friend Arthur Hugh Clough, who died in 1861, after having left Oxford many years before. The walking tour described in "Thyrsis" is based on Arnold's 1861 return visit to the Oxford countryside, to think through his friend's life and their relationship.
What he sees there reflects some of his most common themes, especially when the poem is read in the light of "The Scholar-Gipsy." First, Arnold laments how much the area has changed. Two of his complaints mirror those made in other poems. The most immediate is simply the power of time, which Arnold frequently mentions as a force greater than humans can control. But more poignantly, Arnold sees in the countryside the way the modern world robs nature of its pastoral wonder. The world has not only changed - this might only induce nostalgia. Instead, it has changed for the worse - this induces a great sadness and anger.
Despite the poem's length, it is bookended by an explicit quest: to find the elm. By relating the elm to the scholar-gipsy, Arnold makes the countryside a clear symbol for truth and transcendence. The scholar-gipsy in praised in his eponymous poem for having eschewed the world in favor of a search for truth. That he is deemed a madman means little to him; only the search matters. Arnold's tone grows more frantic and desperate as this poem progresses and he cannot find the elm, reflecting his fear that he will not locate the majestic wonder that nature can bring. Perhaps it is too late for transcendence, and the quest for truth is futile if the elm is gone and the scholar-gipsy is therefore dead.
This desperation is also expressed through the speaker's feelings about Thyrsis, who is clearly meant to represent Clough. Most of the poem criticizes Clough, rather than honors his memory. Instead of lamenting his death, Arnold suggests that Clough gave up, that he chose to give in to the world rather than persevere in the quest he and Arnold were leading towards a greater existence. Now that Clough has died, there is no possibility that Clough will ever resume the quest with his friend.
To better understand this relationship, it is useful to understand the real world context surrounding it. In Victorian England, the brotherhood between a man and his friend was extremely important; since women were not educated, they could not typically offer men a certain form of intellectual companionship. This deep fraternal love between Arnold and Clough was why Arnold was so devastated when Clough died, and also why he was so resentful when he abandoned their "quest."
So Arnold feels betrayed. Since few others were even attempting to understand the scholar-gipsy's quest for truth in a world that was becoming increasingly artificial, the relationship was particularly valuable to the poet. The fact that Clough has recently died only heightens the feelings of betrayal, at least until he comes to terms with it at the end.
This shift is largely effected by the re-discovery of the elm tree. A symbol of both their friendship and their ongoing quest for truth, the fact that it remains suggests that some things are constant. It is steadfast; it perseveres. Faced with that fact, Arnold is able to believe that perhaps his friend did not betray him, but rather only changed the form of his quest. He continued to search, only in a different way. Or put another way, it is wrong for Arnold to criticize Clough when he should be criticizing the world. The latter will change as the landscape has, but the relationship between the men will remain steadfast, as the elm does. And in a larger symbolic sense, it means that the quest for truth - that of both the scholar-gipsy and Arnold himself - is worth continuing.
This poem is long, at 240 lines, and written almost like an epic. Its length adds greatly to its content, since it focuses on a life and a journey, rather than one set instance in time. The rhyme scheme in each stanza is set and consistent, as is the constant use of iambic pentameter. However, the sixth line of every stanza is written in iambic trimeter instead. This interruption of something unusual represents the suddenness of Clough's death, and how it immediately and unexpectedly impacted Arnold's life. And yet the regularity of this unique form only reminds us that no matter how unexpected things might become, we might always find constancy in those most important relationships.