Does the door of your room open from the right or the left? Which is your second longest finger? At a stoplight, is it the red or the green that is on top? How many teeth do you see when brushing your teeth? What letters are associated with what numbers on a telephone dial? If you are in a familiar room, without turning around, write down all the items on the wall just behind you, and then look. I think you will be surprised how little you can retrospect in consciousness on the supposed images you have stored from so much previous attentive experience. If the familiar door suddenly opened the other way, if another finger suddenly grew longer, if the red light were differently placed, or you had an extra tooth, or the telephone were made differently, or a new window latch had been put on the window behind you, you would know it immediately, showing that you all along ‘ knew’, but not consciously so. Familiar to psychologists, this is the distinction between recognition and recall. What you can consciously recall is a thimbleful to the huge oceans of your actual knowledge. Experiments of this sort demonstrate that conscious memory is not a storing up of sensory images, as is sometimes thought. Only if you have at some time consciously noticed your finger lengths or your door, have at some time counted your teeth, though you have observed these things countless times, can you remember. Unless you have particularly noted what is on the wall or recently cleaned or painted it, you will be surprised at what you have left out. And introspect upon the matter. Did you not in each of these instances ask what must be there? Starting with ideas and reasoning, rather than with any image? Conscious retrospection is not the retrieval of images, but the retrieval of what you have been conscious of before, and the reworking of these elements into rational or plausible patterns.

• memory
• time
• will
• experience
• knowledge
• thought
• light
• consciousness
• ideas
• recall
• recognition
• experiments
• other
• patterns
• matter
• numbers