A Foreshadowing of the Productive Role of Imagination in Kant’s Argument from Geometry

The idea of a synthesis was already made apparent in Kant's argument from geometry in the Aesthetic. The perception of geometry is made possible by the pre-conceptual, intuitive synthesis carried out by imagination under the condition of sensibility itself. Kant's famous note at B160-1 seems to smuggle a synthetic unity of understanding into the very unity of space and time. But the difference is that the pre-conceptual, intuitive synthesis carried out by imagination under the condition of sensibility itself is, as it implies, non-conceptual, and is carried out by the imagination with no pure concepts involved whatsoever.