Can a conscious mind be built out of software?

David Gelernter drives yet another stake through the idea of "artificial intelligence":

believe it is hugely unlikely, though not impossible, that a conscious mind will ever be built out of software. Even if it could be, the result (I will argue) would be fairly useless in itself. But an unconscious simulated intelligence certainly could be built out of software--and might be useful. Unfortunately, AI, cognitive science, and philosophy of mind are nowhere near knowing how to build one. They are missing the most important fact about thought: the "cognitive continuum" that connects the seemingly unconnected puzzle pieces of thinking (for example analytical thought, common sense, analogical thought, free association, creativity, hallucination). The cognitive continuum explains how all these reflect different values of one quantity or parameter that I will call "mental focus" or "concentration"-which changes over the course of a day and a lifetime.

Hat tip to David Warren. We make a similar point in The Spiritual Brain.