  Kant argues as follows. Our experiences have objects, that is, they are about something. The objects of our experiences are discrete, unified particulars. To have such particulars available to it, the mind must construct them based on sensible input. To construct them, the mind must do three kinds of synthesis. It must generate temporal and spatial structure (Synthesis of Apprehension in Intuition). It must associate spatio-temporally structured items with other spatio-temporally structured items (Synthesis of Reproduction in the Imagination). And it must recognize items using concepts, the Categories in particular (Synthesis of Recognition in a Concept). This threefold doctrine of synthesis is one of the cornerstones of Kant’s model of the mind. We will consider it in more detail in the next Section.