From ancient Celtic harvest festivals to Christian celebration of All Hallows' Eve to modern trick or treating, Halloween has been when we playfully confront our bogeymen and lay them to rest for another year. If there's one bogeyman science needs to lay to rest it's René Descartes (1596-1650), the thinker often called the father of modern philosophy for the reasoning behind his famous Latin saying, "Cogito ergo sum," ("I think, therefore I am"). As both an animal scientist and a Presbyterian minister, I call Descartes a bogeyman, a vampire of logic who sucked the conscious life out of animals, decreeing that they cannot reason and are only machines made out of meat. This was proven, he asserted, by their inability to learn human language as every child does.
Descartes must never have watched herding dogs demonstrate their problem-solving abilities. And he never had the chance to meet Chaser, the nine-year-old, language learning Border collie that my wife, Sally, and I are proud to count as a member of our family.
Despite resounding blows against the Cartesian system from giants such as Charles Darwin and B. F. Skinner, countless researchers have continued to march, zombie-like, in Descartes's footsteps, insisting that animals lack conscious minds and cannot think, feel (including feel pain, joy, or empathy), or reason. That is a tragic misunderstanding for animals and humans. It's time to drive a stake through the heart of Descartes's twin conceptions of animals as mindless meat machines and the human mind as totally separate from the body, and then nail the coffin shut for good. And the one leading the way is Chaser.
From verbs like "sit" and "come" to proper noun names for more than a thousand of her toys, common nouns, prepositions, adjectives, and adverbs, Chaser has learned a number of basic language concepts just as toddlers do when they first acquire language. Most recently that includes learning to respond correctly to sentences with three elements of grammar, such as "To ball take Frisbee," and a semantic reversal, such as "To Frisbee take ball."
Treating Descartes as a bogeyman on Halloween is especially appropriate because he terrified himself, and by extension of his philosophy all humanity, with an imaginary monster, the Demon of Doubt. And at the root of his thinking about consciousness and the mind-body problem lies a superstition -- a dangerous superstition for science and society - the belief that humans are separate from the rest of nature.
There is no denying Descartes's high stature as a mathematician and an analyst of the human quest for certainty. And he is rightly honored for his good intentions as a champion of free inquiry. He wanted to release philosophy and science from being held hostage to the authority of Aristotle or religious dogma. But in science as in the rest of human life, the road to hell is paved with good intentions. That's where the Demon of Doubt comes in. Because our physical senses often deceive us, Descartes wanted a firm intellectual basis for philosophical and scientific proof, and he asked readers of his Meditations on First Philosophy to "suppose that some malignant demon ... has employed all his artifice to deceive ... [and] that the sky, the air, the earth, colors, figures, sounds, and all external things are nothing better than the illusions of dreams."
In wrestling with the Demon of Doubt in his own mind, Descartes concluded that as long as we are thinking, we can be confident that we exist; that we can know something to be true when we have "a clear and distinct" perception of it in our minds; and that we can be confident about this because the clearest and most distinct idea in the human mind is the existence of God, who would never deceive us. Some of Descartes's closest philosophical correspondents pointed out that there is a circular logic to this, but he insisted that only people whose minds weren't working correctly could fail to see the truth of his assertions. And so the Cartesian circle has continued to spin, keeping far too many scientists' minds as narrowly confined as a hamster in an exercise wheel.
Descartes's bedrock "proof" that animals have no minds or souls (in his scheme mind and soul are the same thing, and he may well have been right about that), was that they could not learn language. At five months old Chaser learned the concept that her toys could have unique names and the referential cues that enabled her to map a name to a toy. Within her first three years she learned, and still remembers, over a thousand proper noun names for her stuffed animals, balls, and Frisbees; many common nouns; combinatorial understanding of the separate meanings of verbs and nouns in her vocabulary; and even how to reason by exclusion, meaning that she can identify a novel object from a group of familiar ones simply by hearing its name for the first time. Since then, she has moved on to mastering sentences with three elements of grammar, as well as progress in learning by imitation, and matching to sample. These are all conceptual steps that have traditionally been thought to be the exclusive preserve of humans.
Darwin argued that dogs can reason and feel empathy (feeling another's plight is a central attribute of "theory of mind" in philosophy and neuroscience). Skinner found that animals make creative "free operant" responses in open-ended learning via operant conditioning. More recently animal scientists such as John Staddon have demonstrated that virtually all animal learning involves conscious or unconscious mental inferences. Today's best young animal scientists, such as Duke University's Brian Hare and the University of Portsmouth's (England) Juliane Kaminski, are showing how dogs and a variety of other animals have an implicit theory of mind that mirrors the implicit understanding of toddlers. Yet Descartes's animals-are-meat-machines paradigm remains extraordinarily powerful.
A paradigm in science holds sway so long as the scientific consensus can ignore or dismiss anomalies that contradict it. But the fate of every paradigm in science is sooner or later to be abandoned, or revised, in the light of persistent anomalies. With her language learning, Chaser joins the chimpanzee Washoe, the dolphins Phoenix and Akeakamai, the African gray parrot Alex, the bonobo Kanzi, and her fellow Border collie Rico as anomalies that can no longer be ignored or dismissed. Together they tell us that it is past time to abandon Descartes's paradigm of animals as machines and replace it with a paradigm of animals as truly our fellow creatures - biologically, emotionally, and cognitively -- and of humans as wholly a part of nature.
So on this holiday of playful engagement with monsters, join Chaser and the rest of her -- and our -- fellow animals, and help nail the bogeyman's coffin shut.
John W. Pilley, B.D., Ph.D., is a Presbyterian minister and an emeritus professor of psychology at Wofford College, and the author, with Hilary Hinzmann, of CHASER: UNLOCKING THE GENIUS OF THE DOG WHO KNOWS A THOUSAND WORDS (Houghton Mifflin Harcourt).