Computer scientist, IBM's T. J. Watson Research Center; Author, Calculus and Pizza

If we believe that consciousness is the result of patterns of neurons in the brain, our thoughts, emotions, and memories could be replicated in moving assemblies of Tinkertoys. The Tinkertoy minds would have to be very big to represent the complexity of our minds, but it nevertheless could be done, in the same way people have made computers out of 10,000 Tinkertoys. In principle, our minds could be hypostatized in patterns of twigs, in the movements of leaves, or in the flocking of birds. The philosopher and mathematician Gottfried Leibniz liked to imagine a machine capable of conscious experiences and perceptions. He said that even if this machine were as big as a mill and we could explore inside, we would find "nothing but pieces which push one against the other and never anything to account for a perception."

If our thoughts and consciousness do not depend on the actual substances in our brains but rather on the structures, patterns, and relationships between parts, then Tinkertoy minds could think. If you could make a copy of your brain with the same structure but using different materials, the copy would think it was you. This seemingly materialistic approach to mind does not diminish the hope of an afterlife, of transcendence, of communion with entities from parallel universes, or even of God. Even Tinkertoy minds can dream, seek salvation and bliss—and pray.