"'This is the way,' laughed the great god Pan,/(Laughed while he sate by the river,)/ The only way, since gods began/ To make sweet music, they could succeed.'"
Pan speaks for the only time in the poem after creating his musical instrument. While he has caused great destruction to nature in the process, he proclaims that his actions were necessary for making his flute. The only way to create such beautiful music was by destroying the reed first. This is the way of the gods since the beginning of time. On a deeper level, the scene may be interpreted as a man taking advantage of a woman and pursuing her beauty at her detriment. He has possessed the reed (the embodiment of the nymph Syrinx) and destroyed her for his own pleasure.
"The true gods sigh for the cost and pain, —/For the reed which grows nevermore again/ As a reed with the reeds in the river."
The final lines of the poem create a somber tone. While Pan has succeeded in creating beautiful music that revives the once-dying nature around him, the true gods are unhappy with his actions. They lament the fact that Pan destroyed their creations (nature) in order to create something new. Beauty has come with a high cost to nature, and they mourn the loss of the poor innocent reed which will never grow again. These lines seem to serve as a warning that beauty perhaps should not be pursued at any cost. Furthermore, human beings are capable of both destroying and creating—and they have the will and rational ability to choose.
"Piercing sweet by the river !/Blinding sweet, O great god Pan !"
When Pan begins to play his new flute, the speaker exclaims with joy that the music is sweet. However, there is an ironic choice of language in this quote. By describing the music as both "piercing" and "blinding," the reader is reminded of the brutality and force that Pan used to create the flute. Therefore, the music he has created may be beautiful, but the speaker is subtly reminding the reader that the means to this end were brutal.
