Topics Perception

Question A spoon half-immersed in a glass of water appears bent at the surface of the water. We know that this is due to refraction of light, which bends the rays of light at the surface, so that the retinal image of the spoon is illusorily bent. So we can speak of the real spoon, which is not bent, and the image spoon, which is bent. They have to be two, because one thing cannot be bent and not bent at once. Since the spoon that I see is bent, it must be the image spoon, not the real spoon. So where is the real spoon?

Accepted:
March 4, 2006

Comments

To my mind, the mistake occurs here the moment you start speaking of "the image spoon". There is no "image spoon". There is just a spoon, and it is in a glass, and you see it. (So the real spoon is in the glass, right where you thought it was.) The spoon looks to be bent, certainly, so perhaps it follows that there is an image of a bent spoon in your head. (Some philosophers would deny that, but I don't think we have to deny it, or should deny it, in order to resolve this puzzle.) But the image of a spoon is not a spoon, and it is not bent, any more than, if I draw a picture of a bent spoon, the graphite somehow becomes a spoon or becomes bent. It's just a picture of a bent spoon, made out of graphite on paper. Nor, most philosophers would hold, is the image of the spoon what you see. What you see is the spoon, in the glass. Perhaps you see the spoon in the glass in virtue of the fact that you have an image of a spoon in your head, but that is a different matter.

Please don't think I'm saying this is a silly mistake. It's not a silly mistake. Philosophers have made this mistake for a very, very long time, and I'm sure there are still philosophers who are inclined to make it. I think it's an important fact about the nature of human perception that we are so tempted to speak the way you do. But—one might well add this to the oft-requested list of subjects on which we philosophers have made some, however halting, progress—we have learned over the last few decades how not to make this mistake.