The secondary imagination is at the root of all poetic activity. It is this power which harmonizes and reconciles opposites, and hence Coleridge calls it a magical, synthetic power.
This unifying power of the imagination, is best seen in the fact that it syntheses or fuses the various faculties of the soul, perception, intellect, will, emotion, and also fuses the internal with the external, the subjective with the objective, the human mind with external nature, the spiritual with the physical or material.
It is through the play of this unifying power that nature is colored by the soul of the poet, and the soul of the poet is steeped in nature.