"It began in the '80's with a mostly one-way 'conversation' with a caterpillar that was chowing down on my basil plants. The more I looked and thought about what it was up to, the more obvious it seemed that everything it did just 'reeked of purpose.'" (Arthur Reber)

I recently learned of a new book called The First Minds: Caterpillars, Karyotes, and Consciousness by Dr. Arthur Reber and was fascinated not only by its title but also by its scope. Based on his own research and that of many others, Dr. Reber argues "sentience emerged with life itself. The most primitive unicellular species of bacteria are conscious, though it is a sentience of a primitive kind. They have minds, though they are tiny and limited in scope. Hints that cells might be conscious can be found in the writings of a few cell biologists but a fully developed theory has never been put forward before." I wanted to learn more about this wide-ranging book and was pleased that Dr. Reber was able to answer a few questions. Our interview went as follows.

Source: Arthur Reber

Why did you write The First Minds: Caterpillars, Karyotes, and Consciousness and how does it follow up with your earlier research?

"Sentience, subjectivity, awareness, feelings, are inherent, essential elements of life, all life." (Arthur Reber)

It began in the '80's with a mostly one-way "conversation" with a caterpillar that was chowing down on my basil plants. The more I looked and thought about what it was up to, the more obvious it seemed that everything it did just "reeked of purpose" -- to use E. C. Tolman's great line about the behavior of a mouse he was "conversing" with. This was the era where Behaviorism was finally losing its grip on psychology and it was becoming more acceptable to endow species up and down the evolutionary ladder with sentience, awareness, cognitive functions.

Those thoughts also fit neatly with my primary research program which was examining the cognitive through the process of "implicit learning." I'd coined that term back in the '60's as a form of learning where skills and knowledge were acquired tacitly, without being able to communicate about what was learned. This caterpillar seemed to be the embodiment of this process. There were things going on inside its head, there was a palpable awareness of , of me. It stepped gently onto my outstretched finger, looked at me and then, as I moved my hand back, returned to a leaf and continued its assault on the only thing I'd grown that summer. I assumed its mental states were primitive, basic. There were no prayers to the gods of basil, no language, was clearly pretty limited to determining which leaf to attack next though it occasionally lifted its head as if to check for predators. I had no idea if it knew anything specific about its condition. But there was no doubt. It was conscious. It had feelings, needs, desires. There is, to paraphrase philosopher Thomas Nagel, something it is like to be a caterpillar.

Source: Pixabay Creative Commons

I had no idea where to go with this insight so I just stuck it in that clichéd spot, the "back burner." Then, in 1995, we spent the year at the University of Wales at Bangor and the British Psychological Society invited me to speak at their annual gathering. It seemed like the right time to take the notion of a conscious caterpillar and push the envelope a bit and what better place to do it than in front of a muster of British academics. So I pushed … for the only logical point was that this mental stuff didn't start with caterpillars or octopuses or bonobos or us. It's been there all the time. Sentience, subjectivity, awareness, feelings, are inherent, essential elements of life, all life.

I gave a presentation on "Caterpillars and Consciousness." It landed with a dull thud. Everyone upped and left with nary a howl of outrage. Later I discovered that the society had decided that the usual Q & A was going to be abandoned when "dicey" topics were presented. Mine fit the bill for "dicey." I decided to try the journal route and in 1997 a paper with the same title appeared in Philosophical Psychology. It promptly faded from sight. I think it's been cited maybe three times and one of them was by me. Clearly, either no one was interested in my model or they all simply thought I'd lost my mind and were being diplomatic about it.

Then Stevan Harnad started the journal Animal Sentience. Stevan was in the audience back in '95 and I thought he might be open to my resuscitating the "Caterpillars" argument for the journal. He was. "Caterpillars, consciousness, and the origins of mind" appeared in 2016. Because Animal Sentience is an open, peer-reviewed journal, I got the kind of vigorous debate I'd hoped for twenty years earlier. The give and take there made me realize that I needed to hone my arguments more carefully, explore the database more thoroughly, and dig deeper into the various alternative visions others had on this and related issues. When I felt comfortable, I contacted my old friends at Oxford University Press and it led to where we are with The First Minds: Caterpillars, 'Karyotes, and Consciousness.

What do you mean when you say you write about the "cellular basis of consciousness" (CBC) and what are your major messages.

It's pretty basic. Once you recognize that life without awareness — life bereft of sentience — is an evolutionary non-starter, then it becomes obvious that consciousness is coterminous with life. And, since life began with unicellular prokaryotes, the conclusion forces itself upon you: unicellular organisms have a (rudimentary) consciousness. Understand, this notion isn't original with me. Lynn Margulis, the prominent cell biologist and champion of the processes of symbiogenesis, once wrote a paper titled "The conscious cell" and various other thinkers have reached the same conclusion. What was missing, however, was a broadly considered set of arguments that covered, not just the basic presumptions about the origins of mind, but presented critical assessments of the many other views of the emergence of mental life and, importantly, took into account the philosophical entailments that accompany a model like the CBC.

How do your ideas fit in with other efforts to understand consciousness?

Ever since philosopher David Chalmers dubbed the struggle to understand consciousness the "Hard Problem," a veritable cottage industry sprung up seeking, if not solutions, at least laying out pathways that might lead there. The enterprise includes scientists in the field of , biologists, neuroscientists, psychologists with a variety of specializations, philosophers, mostly those who focus on the of mind and, perhaps surprisingly, physicists and mathematicians. In fact, in 2005 the journal Science named Greg Miller's essay "What is the Biological Basis of Consciousness?" the second most important unsolved scientific problem ("What is the universe made of?" was #1). The bookshelves are filled with efforts to unravel the mystery of consciousness, some of them quite interesting, original and thoughtful.

I had three things I needed to do. First, show that these other approaches were either fatally flawed or so encumbered with philosophical, biotechnical, and logical problems that they simply were not viable. Second, lay out what is known about the functions of unicellular species that supports the core arguments of the CBC. And third, critically discuss the various philosophical perspectives that a theory like mine demands you to pay to.

The description for your book states, "the implications of the CBC model are discussed along with a number of related issues in evolutionary biology, philosophy of mind, the possibility of sentient plants, the ethical repercussions of universal animal sentience, and the long-range impact of adopting the CBC stance." Can you please tell readers some more about why you argue that life and sentience are coterminous and about these implications of your arguments and why they are important?

The first problem anyone looking for the origins of consciousness, of mind, confronts is the Emergentist's Dilemma. You are going to have to determine how minds, awareness, consciousness, sentience (it doesn't matter what you call it) suddenly appears in some species when one cosmic moment earlier it wasn't there. The standard approach to this issue has been to begin with human consciousness and ask the key questions: We know we have this mental life. Do other species? Which ones? How would we know?

This, not unreasonable, approach led folks to embark on two research programs. One sought to identify the criterial neurobiological features that are responsible for human consciousness and look back through the evolutionary tree for species that had those features or analogues of them. The other focused on analyzing the behavioral repertoire of other species looking for functions that showed (or strongly suggested) that they had a mental life that was determinate of consciousness.

These endeavors, which are still going on, produced wonderful insights into the rich, varied, and often startlingly sophisticated mental lives of many species --- but it produced nothing but confusion in terms of spotting that hypothesized miraculous moment when a species took that quantal step from an insentient automaton to one with a mind. In The First Minds a baker's dozen of these efforts are reviewed and critiqued for none of them manages to put forward a biological framework or evolutionary timeline that satisfies.

The alternative answer, the one I offer is that when life first bloomed from the prebiotic slurry over three billion years ago it emerged with a host of functions and one of them was sentience. All forms of consciousness right up to us with our big brains are simply products of evolutionary mechanisms. It all happened just once and …well … here we are. I appreciate that I can't duck the emergentist's dilemma but mine is a far more tractable one than the others. My guess is it will be found when we unpack the biomolecular processes and mechanisms that gave rise to life itself.

So, what about plants?

Ah, plants. There are quite a few cell biologists and botanists who argue that plants are conscious. I'm agnostic on this issue but recognize it cannot be avoided. Plants first appeared some two billion years after Prokaryotes. If those unicellular critters had minds, then plants, which evolved when a species of bacteria was incorporated by a photosynthesizing eukaryote, should as well. There is a long section in The First Minds on the possibility of sentient plants. I also touch on a number of ethical issues, in particular, those that might make some vegetarians and vegans feel a tad uncomfortable.

How do you answer skeptics who think you've gone too far -- there's no way that cells are conscious and that sentience emerged with life itself. Surely, they would argue, there has to be some 'line' below which sentience doesn't exist.

"When you look at the literature you find a marvelous array of proposals about where to draw that line. One or another researcher has concluded that consciousness first appeared in worms, insects, cephalopods, birds, mammals, and primates." (Arthur Reber)

Well, I certainly appreciate the perspective of the skeptics. When I wrote "Implicit Learning and Tacit Knowledge" it was after my chat with that caterpillar and I was fairly certain that something like the CBC theory was correct but I ducked. I didn't want to put a bullseye on my back so I included a section concluding that a sentient prokaryote was a bridge too far. And I wasn't alone. A prominent cell biologist told me that while giving a talk he entertained the possibility that amoebae had a form of consciousness. The proposal was greeted with such a display of derision that when he wrote a book on cellular functions he too concluded that prokaryotes were not conscious. Since then he's changed his mind and agrees with the basic tenets of the CBC. There's no doubt that assaults from critics both within and outside of the academy can be intimidating. But I'm old now, retired, and don't worry much about this. But I am a scientist and one thing we all learn early on is that we best be prepared to be shown to be wrong. I might be. However, mainly, I hope to stimulate discussion.

But let me dig down a bit more to answer your question about a "line" below which there is no sentience. When you look at the literature you find a marvelous array of proposals about where to draw that line. One or another researcher has concluded that consciousness first appeared in worms, insects, cephalopods, birds, mammals, and primates. There are others who argue that only humans, with our linguistic abilities, can be conclusively said to have consciousness. There are still others who argue that consciousness is simply the result of carrying out just the right computations and that we will someday in the not so distant future be confronted with a conscious AI.

And let me be clear. These are not proposals entertained by crackpots. These are seriously, carefully crafted models put forward by respected scholars. But I found a fascinating pattern in my wandering through this research realm. Entomologists usually identified insects as the origins, avian researchers and ornithologists argued that it first emerged in birds, primatologists identified chimpanzees or monkeys, linguists tended to think it’s a privileged property of Homo sapiens. The (obvious?) conclusion: sentience, mental life is there in all. Wherever you look you will find it.

Who is the audience for your book?

The clichéd cohort: intelligent laypersons with curious minds. I tried my very best to write for everyone while staying true to the standards of bio-evolutionary science and, critically, my friends and colleagues in the philosophy of mind. Back in 1981, I was fortunate to be one of the psychologists invited to join a coterie of philosophers in a six-week long NEH-sponsored summer institute on the Psychology and Philosophy of Mind. It was a revelatory experience. I thought I knew something about the philosophy of mind. I quickly discovered I didn't. I thought I had useful, creative insights to offer. Nope. But I struggled and learned and, in retrospect, now over 35 years later I know, for certain, two things. I could not have written this book without that summer and, importantly, I would never have even attempted it if I'd had formal training in philosophy.

What are some of your current and future projects?

Two things. One is a with František Baluška, a cell biologist at the University of Bonn. We're working on arguments that will hopefully nail down the proposition that life and sentience are biologically linked, that it is simply not possible to have living organisms without, simultaneously, a primitive mental life. We're also (well, mainly František and his colleagues) working to identify the biomolecular processes that are responsible for sentience. We view our work as an adjunct to ongoing research programs in several universities seeking to identify the mechanisms that make life possible.

The other is a volume that Rhianon Allen and I will edit. The working title is The Cognitive Unconscious: The First Half-Century. It will bring together and review the study of implicit learning and and the various applied areas where it's had an impact. Honestly, when I began researching implicit learning back in the '60's I hadn't a glimmer of how wide-spread it would become. Rhianon and I will write two or three chapters, the other twenty or so will be contributions from leading scholars.

And, if I can find the time, I'd love to write another novel, one that spins off my first effort at literary fiction, Xero to Sixty which can be found, of course, on Amazon. It's a lot of fun being retired!

Is there anything else you'd like to tell readers?

I have a thousand things to say, perhaps I'll get to them in the future.

Thank you so much for a most interesting and candid interview. It's refreshing to hear about the ups and the downs of your long-term research. I look forward to seeing more discussion about what some might call your "radical" -- some might say outlandish -- ideas. I find your arguments to be important for all discussions about the evolution of consciousness, and I'm pleased they're getting significantly more attention than they did when you first (courageously) put them out for public scrutiny. I thoroughly agree with renowned University of Southern California Antonio Damasio's endorsement for your book: "It is not necessary to agree with all the ideas advanced in Reber's new book to recognize it as a major contribution to the study of consciousness and to recommend it with enthusiasm to anyone interested in understanding how humans came to be conscious." Good luck with all you're doing.