The difference between a brain and a computer can be expressed in a single word, that is, complexity. The large mammalian brain is the most complicated thing, for its size, known to us. The human brain weights 3 ponds, but in that 3 ponds are 10 billion neurons and a hundred billion smaller cells.// Even the most complicated computer man has yet built can’t compare in intricacy with the brain. Computer switches and components number in the thousands rather than in the billions. What’s more, the computer switch is just an on-off device, whereas the brain cell is itself possessed of a tremendously complex inner structure.// It is frequently said that computers solve problems only because they are “programmed” to do so. They can only do what men have them do. One must remember that human beings also can only do what they are “programmed” to do. Our genes “program” us and our potentialities are limited by that “program”.// Our “program” is so much more enormously complex, though, that we might like to define “thinking” in terms of our creativity in literature, art, science and technology. In that sense, computers certainly can’t think.//