'This is a great poem and has some amazing symbolism woven in. It basically attempts to describe the ecstatic feeling associated with shifting consciousness and then drawing artistic inspiration from that experience.

In the first stanza, the spirit (consciousness) of the poet rises above the earthly confines and floats upward into the cosmos. This represents the psyche transcending its worldly bonds and being freed to explore the vast mystery of the deep subconscious.'

https://stuffjeffreads.wordpress.com/2014/09/21/elevation-by-charles-baudelaire/