I present a new theory of how organized neural networds can create the rich phenomena of the conscious mind, which builds on an earlier theory first proposed by Donald Hebb. Starting from some basic philosophical considerations, I review the natural history of the neuron and neural systems in the lower animals, consider the selective pressure of human evolution, and show how timed networks or "cascades" can explain all of the phenomena we ascribe to "mind," as well as fit many other behavioral and experimental observations. I conclude with some proposals for future research to test the theory and suggest what kind of computer models might be able to replicate these systems.