My favorite demonstration of how surprisingly little people perceive is quite simple. I set a tray with a bottle of water and several glasses on the table, call express attention to what is about to occur, and pour a little water from the bottle into the glass. Then the stuff is taken away and the astonishing question asked what have I done? All the spectators reply immediately: you have poured water into a glass. Then I ask further with what hand did I do it? How many glasses were there? Where was the glass into which I poured the water? How much did I pour? How much water was there in the glass? Did I really pour or just pretend to? How full was the bottle? Was it certainly water and not, perhaps, wine? Was it not red wine? What did I do with my hand after pouring the water? How did I look when I did it? Did you not really see that I shut my eyes? Did you not really see that I stuck my tongue out? Was I pouring the water while I did it? Or before, or after? Did I wear a ring on my hand? Was my cuff visible? What was the position of my fingers while I held the glass? These questions may be multiplied. And it is as astonishing as amusing to see how little correctness there is in the answers, and how people quarrel about the answers, and what extraordinary things they say. Yet what do we require of witnesses who have to describe much more complicated matters to which their attention had not been previously called, and who have to make their answers, not immediately, but much later; and who, moreover, may, in the presence of the fact, have been overcome by fear, astonishment, terror, etc.! I find that probing even comparatively trained witnesses is rather too funny, and the conclusions drawn from what is so learned are rather too conscienceless.[194] Such introductions as: “But you will know,”--“Just recall this one,”--“You wouldn’t be so stupid as not to have observed whether,”--“But my dear woman, you have eyes,”--and whatever else may be offered in this kindly fashion, may bring out an answer, but what real worth can such an answer have?
One bright day I came home from court and saw a man step out of a cornfield, remain a few instants in my field of vision, and then disappear. I felt at once that the man had done something suspicious, and immediately asked myself how he looked. I found I knew nothing of his clothes, his dress, his beard, his size, in a word, nothing at all about him. But how I would have punished a witness who should have known just as little. We shall have, in the course of this examination, frequently to mention the fact that we do not see an event in spite of its being in the field of perception. I want at this point merely to call attention to a single well-known case, recorded by Hofmann.[195] At a trial a circumstantial and accurate attempt was made to discover whether it was a significant alteration to bite a man’s ear off. The court, the physician, the witnesses, etc., dealt with the question of altering, until finally the wounded man himself showed what was meant, because his other ear had been bitten off many years before,--but then nobody had noticed that mutilated ear.