Where true Love burns Desire is Love’s pure flame;
It is the reflex of our earthly frame,
That takes the meaning from the nobler part,
And but translates the language of the heart.
This is a very short yet very moving poem. Coleridge is essentially comparing and contrasting Love and Desire. For Coleridge, Love comes from the soul. It is a spiritual connection with another human being that transcends this earthly plane. And since Love, like all things spiritual, is impossible to express through normal means, it must be expressed through symbols, and Desire is the symbol by which a person can express Love. Desire is the physical expression of spiritual Love.
There is really not much else I have to share about this poem. I hope you enjoyed it as much as I did. Cheers!