The original source or moment of apprehension, or call it just prehension, is neither like pure perception nor pure ideation or conceptualisation, but a fusion of the two. A perception is only realised via a concept, a whatness, and a concept does not arise without an arising, a thatness. Whatness and thatness are in a sense orthogonal, they do not fuse. They are distinct 'directions', like two eigenvectors of a single transformation, or act before all action.