Here's a fascinating question that can never be asked scientifically: What is the nature of consciousness? No experiment can even show that consciousness exists (see my June 2006 column to be reminded why). Fortunately, there are ways to get closer and closer to this impossible topic. For instance, it is possible to ask what meaning is, even if we cannot ask about the experience of meaning.
V. S. Ramachandran, a neuroscientist at the University of California at San Diego and the Salk Institute, has come up with a research program to approach the question of meaning with remarkable concreteness. Like many of the best scientists, Rama (as he is known to his colleagues) is engaged in an extension of his childhood curiosities. When he was 11, he wondered about the digestive system of the Venus flytrap, the carnivorous plant. Are the digestive enzymes in its leaves triggered by proteins, by ...