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Did Consciousness Evolve?: A Darwinist Responds

Jerry Coyne argues that consciousness is a mere byproduct of useful traits that are naturally selected. But wait…

Evolutionary biologist Jerry Coyne (right) published a post the other day attacking philosopher Bernardo Kastrup’s recent observation that consciousness cannot have evolved. Prior to attempting to debunk it, Coyne summarizes Kastrup’s argument:

1.) Evolution is a materialistic process.

2.) The salient characteristic of materialism is that all entities “are defined and exhaustively characterized in purely quantitative terms”.

3.) Consciousness cannot be characterized in quantitative terms: it is a qualitative and subjective property manifested by qualia: the sensations that inhere in “consciousness” like (classic example) “what it is like to see red” or “what it feels like to hear a Vivaldi sonata.”

4.) Ergo consciousness is not explainable by materialism.

5.) Materialism must therefore not be a universal explanatory schema for understanding nature; as Kastrup says, “Our very sentience contradicts materialism.”

6.) Because experience or qualia are not “materialistic” phenomena, they “cannot have a function under materialism”. Therefore, “It must make no difference to the survival fitness of an organism whether the data processing taking pace in its brain is accompanied by experience or not.” [JAC: note that natural selection is about reproduction, not survival itself].

7.) Therefore, qualia and consciousness could not have evolved by natural selection.

Jerry Coyne, “Muddled philosopher: Consciousness could not have evolved” at Why Evolution Is True

So what is Coyne’s response?

Traits can evolve but need not have evolved by natural selection. They could be byproducts (“spandrels”) of other traits that were selected, like the red color of our blood that’s simply the color of hemoglobin, or they could have been “neutral” traits that came to predominate by random genetic drift (much evolution of DNA sequences is of this sort). Or they could even be detrimental, rising in frequency in small populations despite counterselection (the high frequency of genetic diseases in small populations is likely due to this). Many scientists think, for instance, that consciousness may not have been selected for directly, but is simply an epiphenomenon—a byproduct that appears when neurological complexity reaches a certain level. Our ability to play chess or do advanced mathematics, for example, are epiphenomena of this type, for they certainly weren’t objects of selection. They were things that became possible when our brains got sufficiently large and complex…

And if consciousness is either a spandrel, a byproduct of neutral evolution, or the direct object of selection, it is still a property of our brains, for there are many experiments and studies showing that consciousness can be affected or removed or altered by manipulating our brains. If this be true, then consciousness must have evolved one way or another, even if not by selection.

Jerry Coyne, “Muddled philosopher: Consciousness could not have evolved” at Why Evolution Is True

Coyne’s response makes clear that Darwinian evolutionists like himself understand the problem that Kastrup (right) raises. His response is a standard one: Consciousness is a spandrel — an unselected trait that is genetically linked to a selected trait. Your brain helps you survive and consciousness is a spin-off of this adaptation. From the Darwinian perspective, subjective experience is a byproduct (an epiphenomenon) of brain function.

The problem with Coyne’s spandrel/epiphenomenal hypothesis is that even if the Darwinian mechanism (“survivors survive”) were a meaningful scientific inference, it can only explain the survival of consciousness, not the arrival of consciousness. To figure at all in evolution, consciousness must first exist and the Darwinian mechanism can’t explain its origin. At best, Darwinism can only explain changes in consciousness over time.

Furthermore, if human consciousness did indeed “evolve,” it had to be present in some way in inanimate matter as a substrate on which natural selection could act. Thus, the assertion that consciousness “evolved” is either empty (it doesn’t explain the arrival of consciousness, only its survival) or it presupposes panpsychism — the presence of consciousness in inanimate matter. Panpsychism is anathema to materialists like Coyne, who desperately try to eliminate Mind from nature.

Kastrup is, of course, basically right about consciousness and evolution. Consciousness is an enormous problem for Darwinian theory, because a meat robot with only a third person existence could “evolve” to perform every behavior that a human being with conscious first person existence could do. In philosophy, that is called the p-zombie problem. And it is only behavior that can serve as a substrate for natural selection. Natural selection isn’t based on what you “feel” — it is based only on what you do. There is no survival advantage for subjective existence over objective existence.

Kastrup is right: It’s nonsense to say that consciousness evolved. But all Darwinism is nonsense, so why should a Darwinian approach to consciousness be any different?

Here are some of neurosurgeon Michael Egnor’s earlier reflections on consciousness:

Can we engineer consciousness in a robot? One neuroscientist thinks we need only “simple guidelines.” His underlying assumptions are just wrong

Neuroscientist Michael Graziano should meet the p-zombie. A p-zombie (a philosopher’s thought experiment) behaves exactly like a human being but has no first-person (subjective) experience. The meat robot violates no physical principles. Yet we KNOW we are not p-zombies. Think what that means.

Did consciousness “evolve”? One neuroscientist doesn’t seem to understand the problems the idea raises. Darwinian evolution must select physical attributes. If consciousness evolved as a mere byproduct of physical brain processes, it is powerless in itself. Thus Graziano’s theories of consciousness are themselves mindless accidents.


Did consciousness evolve to find love? It’s an attractive idea but it comes with a hidden price tag If consciousness is a mere tool of human sexual selection, it is mere plumage, a pretty enticement, of no meaning or import otherwise. But then what becomes of Dr. Graziano’s own intellectual labors?

Also: Bernardo Kastrup: Consciousness cannot have evolved. How many joules of consciousness would make you a human instead of a chimpanzee? How many more joules of consciousness would make you a genius? Computer scientist and philosopher Bernardo Kastrup argues that evolution deals with things that can be measured quantitatively but consciousness cannot be quantified. 

Michael Egnor

Senior Fellow, Center for Natural & Artificial Intelligence
Michael R. Egnor, MD, is a Professor of Neurosurgery and Pediatrics at State University of New York, Stony Brook, has served as the Director of Pediatric Neurosurgery, and award-winning brain surgeon. He was named one of New York’s best doctors by the New York Magazine in 2005. He received his medical education at Columbia University College of Physicians and Surgeons and completed his residency at Jackson Memorial Hospital. His research on hydrocephalus has been published in journals including Journal of Neurosurgery, Pediatrics, and Cerebrospinal Fluid Research. He is on the Scientific Advisory Board of the Hydrocephalus Association in the United States and has lectured extensively throughout the United States and Europe.

Did Consciousness Evolve?: A Darwinist Responds