The IMAGINATION then, I consider either as primary, or secondary. The primary IMAGINATION I hold to be the living Power and prime Agent of all human Perception, and as a repetition in the finite mind of the eternal act of creation in the infinite I AM. The secondary Imagination I consider as an echo of the former, co-existing with the conscious will, yet still as identical with the primary in the kind of its agency, and differing only in degree, and in the mode of operation. It dissolves, diffuses, dissipates, in order to recreate; or where this process is rendered impossible, yet still at all events it struggles to idealise and unify. It is essentially vital, even as all objects (as objects) are essentially fixed and dead.
Samuel Taylor Coleridge, Biographia Literaria
Kant describes two stems of knowledge in the Introduction to the Critique of Pure Reason, a distinction between sensibility and understanding which becomes ever more elaborate as we examine the relationship between the two stems. We will find that the explication of this relationship necessitates an examination of the primary role of the imagination in the grounding of synthetic a priori judgments. In other words, through a consideration of the relationship betwixt the faculties of sensibility and understanding, and of the transcendental distance which separates them, we will begin to comprehend the necessity of a third primary faculty of knowledge, but one, paradoxically for Kant, which will not ultimately be considered either as a root, or a stem of knowledge.
To read the rest of the essay, please visit Imagination in Kant’s First Critique.