Perception (n.) is less of a recording system and more of a protection system against external stimuli.
Perception (n.) that goes unnoticed feeds the dream; what was consciously seen in the picture never returns at night.
Perception (n.) must forget in order to stay open: the system that receives fresh stimuli can keep no trace of them, so memory is handed to another system behind it.
Perception (n.) is to the ego what instinct is to the id.
Perception (n.) falsifies for the sake of intelligibility: we cannot see unfamiliar signs or hear unknown words without at once bending them into something we already know.
Perception (n.) follows understanding: what has not been understood has been inaccurately perceived.
Perception (n.) is not passive: the ego keeps sending out little feelers of attention to taste the world, then pulls them back.
Perception (n.) needs a shield, an outer layer that softens incoming stimuli, like the celluloid sheet over the writing-pad's waxed paper.
Perception (n.) is the unconscious reaching out feelers through consciousness toward the world, and pulling them back, in rapid pulses.