ABSTRACT
But I am running ahead of myself. There is much ground to be cleared before the idea of perception outlined above can be substantiated. To begin this clearance we need to inquire more closely into the assumptions we tend to make about our experiences of seeing and hearing. You can attempt to find out what these are by performing a simple thought experiment. Suppose you are standing beside the tracks as a train is passing. You see the locomotive and the coaches hurtling by, you hear the roar of the engine followed by the clickety-clack of bogies as they roll over joints in the rail. These sights and sounds are ordinarily so entangled in your experience that it is not easy to tell them apart, to imagine what the train would look like without the noise it makes, or what it would sound like without the appearance it presents. But you could try, nevertheless. Picture yourself blindfolded, or on a pitch dark night, such that the visual component of experience is eliminated. The sound of the approaching train, as it swells, seems to assault and ultimately to overwhelm every fibre of your being. You cannot resist being swept along with it until eventually, as the train recedes into the distance, you are left stranded by the trackside, breathless and dizzy, in exactly the same spot where, in truth, you had been standing all along! But now, as a second experiment, picture yourself with your ears stopped, so as to cut out the auditory component of experience. This time the train appears to pass before your eyes as though it were a spectre whose very existence lies in dimensions other than those of the world to which you belong. You see it, you register its presence and its passing, but you are not moved by it. The vision is just another sighting to add to your collection.
