Nagel's argument is that the mechanics of natural selection can't answer one of the most crucial questions of our existence: how living, reasoning creatures emerged from insensate matter. Although he himself is an atheist, Nagel says he shares the theists' conviction that the appearance of such creatures strongly suggests that the universe has, from the beginning, evolved teleologically, meaning it's moving purposively, toward ever-higher levels of consciousness.

"Each of our lives," he writes, "is a part of the lengthy process of the universe gradually waking up and becoming aware of itself." In the present intellectual climate, Nagel hastens to add, "such a possibility is unlikely to be taken seriously."

He got that right. Mind and Cosmos has been the subject of a number of high-profile takedowns, earning it top honors in the Guardian's list of Most Despised Science Books of 2012. So vitriolic has been the response that, as Jennifer Schuessler pointed out in the New York Times, even a relatively sympathetic review ran under the headline, "Thomas Nagel is Not Crazy."

My purpose here is not to review the Nagel controversy (the Times article includes a generous sampling of links for those interested in such a review), but rather to add some historical context by pointing out the striking parallels between his arguments and those made more than a century ago by one of my heroes, the great Samuel Butler.

Butler is best known as the author of the fantasy novel Erewhon, published in 1872. Erewhon, in turn, is best known for its extended meditation on the possibility that machines might one day attain consciousness and take over human beings.

The central character in Erewhon, unnamed in the original novel but identified in the sequel as Higgs, is a hiker who becomes lost in the mountains and stumbles upon an isolated civilization called Erewhon ("nowhere" spelled backward, sort of). Higgs learns that, five hundred years before his arrival, the citizens of Erewhon were alerted to the danger of technological revolt and banned the use of anything but the most primitive machines. The rationale behind this decision is spelled out in a manifesto called The Book of the Machines, which serves as a vehicle for Butler's musings on the implications of Darwinism.

The basic argument in The Book of the Machines is that technology is just as subject to the laws of evolution as plants and animals. There had to have been a moment in biological history when matter made the leap from inert to alive. Who's to say that at some point machines won't make the same leap? The speed of technological progress suggests they're already half way there.

The playful, almost absurdist tone of the Book of the Machines made it easy to conclude that Butler was making fun of Darwin - The Origin of Species had been published 13 years earlier, and remained hugely controversial. Butler denied it. He told Darwin in a letter that he'd intended only to demonstrate, for purposes of his own amusement and that of others, how easily a scientific concept could be distorted by exaggerated analogy.