There are some books so good that they’re worth reading even if you disagree with them. This is one of them.
Most of the book is dedicated to a tour de force through computing, mathematics, and physics. The book is intended to be read by laymen, though sometimes the “simplifications” seem to make things more complicated at first. I read every word, but I think I only understood around twenty percent of the book, and most of that was things I already knew.
Of course, I actually agree with Penrose’s main argument, but I know (and Penrose readily admits) it’s quite controversial. The argument? It is that theorems such as the Halting Problem and Gödel’s incompleteness theorem prevent a strong AI from ever being created, or, in short, that brains are not computers.
Penrose’s specific argument relies on a kind of mathematical Platonism, again, a controversial view. I’m not sure if I agree with the existence of numbers as some kinds of eternal, uncreated things. Did God create the integers, or are integers an aspect of God? Certainly mortal conceptions of logical systems are flawed, as shown by Godel’s incompleteness theorem. But from God’s perspective, knowing through Omniscience all true logical propositions, is He seeing the Creator or Creation?
The form of objective reduction of Quantum Mechanics that Penrose proposes does not actually rely on observer effects, which is relieving. Penrose has a point that a world requiring conscious beings to collapse waveforms is absurd in that most of the universe does not actually exist. This does bring the question of how free will interacts with the world, but Penrose does not claim to explain everything in Heaven and Earth, but only that the emperors of Strong AI are naked.