Consciousness and Sentience

Last revised April 17, 2017

Conscious? Here’s a contender. Understanding the evolution of consciousness will not come from looking for intelligent behavior in other animals, but rather from understanding the fundamental mechanisms that support subjective awareness and selective attention, which we now know insects have.1

Consciousness is a summary, produced by the non-conscious brain, and tossed up for us to view. Consciousness requires extra brain work to produce. The hard parts of thinking all happen below the level of consciousness, and requires extra effort for it to tap what is going on below. The thinking that our brain does below consciousness, or before we are consciously aware of what it is doing, is the important part. All animals have the general capabilities of that most important part, and whether they are conscious or not doesn’t much matter.

In high school algebra, I knew that I knew the answer to a question the moment it was asked (“If a train leaves Chicago heading west…”). It was inevitable that I’d need to explain my answer to the class, and that was the hard part. Between my raised hand and my need to start talking, I’d be scrambling to scrape some acceptable words up from the muddy floor of my brain. It always seemed to work, and it has convinced me that we can know we know before we can say what we know, that consciousness is, literally, an after thought.

Are we Special?

In the history of human thinking about humans, it has been the fashion to assume that humans were superior to all other species, and then to simply look for ways that we were different, and thus better.

Once upon a time, there were many ways that humans were superior to lesser creatures. We had morality, culture, tool use, and language, and they did not. But in recent years, we have learned that these things are found in animals. Fish have a sense of morality and fairness. Birds speak dialects and have local ways of doing things. Many animals use tools, like the octopus who carries half of a coconut shell to hide in when needed. Dogs have shown an ability to master a very large vocabulary, and to understand subtle differences in sentence structure. Parrots have demonstrated an ability to pronounce and use words correctly, and to combine them into syntactically correct sentences. Poor us. What is left to prove that we are better than the beasts?

The advantage that humans have over other animals in establishing our superiority: animals can’t talk. If I tell my horse that he is stupid, he won’t deny it. If I put a bit in his mouth and tell him “this won’t hurt”, he won’t argue. Other animals don’t talk either, so it is easy to believe what we want about them.

Consciousness cannot be a property unique to humans. If I tell you that horses have consciousness, I mean only that they can do things like visualize getting into a warm barn on a cold winter day, and imagine the grain bucket that will be waiting for them. I do not mean that they can play chess. And humans are not so great at it, if you want to know the truth. I regularly encounter fender benders on the road, in which the following driver apparently was not consciously attending to the task at hand.

For myself, I’ve driven through intersections, only later to realize that I wasn’t consciously aware of processing the information about the traffic and traffic signals. Or driving through a familiar neighborhood, I suddenly wonder where I am. Yes, I’m headed towards senility. I might be able to get along just fine without consciousness, but I don’t think I’d always make it home, or get to finish this book.

How Many Angels can Dance On the Head of a Pin?

There is a school of thought that says about animal consciousness: if you can’t prove it, then it doesn’t exist. And there are others that think we never sent humans to the moon, or that the massacre at Sandy Hook was fake news.

Consciousness is something like angels on a pin. Until we can get our hands on one, and measure her, we can’t answer the question. Like angels, philosophers can’t even agree on what consciousness is, and what we are looking for. Wikipedia notes that consciousness “has been defined as: sentience, awareness, subjectivity, the ability to experience or to feel, wakefulness, having a sense of selfhood, and the executive control system of the mind.2” In my experience, anything with so many definitions is not very useful, and maybe doesn’t exist.

A Matter of Degree?

Take any aspect of our notions of how we are special, and I will tell you about some other animal that shares this quality.

You think that only humans admire beauty?

  • We live in the woods, and I’ve put up a dozen squirrel nest boxes. The top of the nest boxes is nearly horizontal, with just enough slope to shed the rain. Routinely, summer or winter, I’ll see a squirrel relaxing on the roof of his nest box, facing the sun as it sets. The sun has lost its power to warm, and he must be facing it to watch it.
  • Just before sunset I was driving along a little country road. I came to a hill in a pasture at the side of the road. There were 50 geese on the hillside, all standing entranced by something, all standing quietly looking at something. I turned to look as they were. The sun was going down, and it was spectacular. I drove just a little more, and now the other side of the hill was in view. There were another 50 geese on this side, but the top of the hill prevented them from seeing the sunset. On this side, the geese were oriented in all directions.

If geese and squirrels can find delight in watching the setting sun, who am I to argue that they aren’t just like me, that they can’t appreciate the things I appreciate, that they do not have consciousness and are therefore subhuman?

You think only humans reflect on the day they have had, or their plans for tomorrow?

  • I have a snail that dreams, like so many other animals that dream. Living in my salt water tank, he has grown large and heavy, so at night when he sleeps he does so in the front of the tank, where he can support his weight by attaching to the glass at the bottom, relaxing his shell on the sand and hanging on to the front of the tank with his foot. During the day on the front of the tank, he shows me what is going on under that shell: his radula grinds away in an arc, from one side to the other. Then he moves slightly forward, and arcs back, removing algae from the front of the tank and swallowing it. Like his antennae, his eyes, on stalks, keep a vigil for danger, food, and the other things he is interested in. When he sleeps, his eyes withdraw, his antennae withdraw, and his his head stops moving from side to side. But he dreams! I often find him with eyes and antennae withdrawn, chewing slowly on the glass. He is not moving forward. His mouth is not moving back and forth in an arc, so his mouth is not finding anything tasty to swallow. But nobody said he couldn’t dream about eating.

You think only humans grieve?

  • We have a 20 year old cockatiel we hand-raised named Freckles. He and his siblings and others lived in the house in an aviary — a large room with branches hanging from the ceiling. One tragic day, Freckles’ wife died. We took her body away. Freckles called for her for the next 8 hours, without a break.
  • Driving along the parkway one hot summer day, I saw a Mallard duck sitting on the curb. I stopped, and saw that his wife had been hit by a car, and was in the road at his feet. I picked up her body, and walked it away from the road to a bush. The drake followed me closely, and went under the bush to stay with her.

I have 100 stories like this, but I won’t take your time. Grieving has been well documented in many sources.3

If you think that horses don’t have consciousness, you need to neglect the conclusions of many scientists. As I said in the earlier section on “About this Book”, we don’t own consciousness. Non-human animals, including all mammals and birds, and many other creatures, including octopuses, also possess these neural substrates.

The differences between humans are differences of degree, not kind. The differences between horses are differences of degree, not kind. The differences between humans and any other animal is a matter of degree, but not of kind. As far as I’m concerned, there is no gulf between me and my horse. I am not better than him just because I can play chess or operate a pogo stick. I’m happy to believe that he is conscious, that horses are conscious — especially if such beliefs bring us closer together.

Charitable Views

My own position on consciousness is charitable. Of course my horse is conscious. He can review activities and re-enact them in his REM sleep. He can make his plans as he approaches the gate of his pasture. He can recall which way this trail goes, and tell me whether he is happy to take it. He can anticipate what might happen to us if he crosses that rickety wooden bridge, and opt for a safer route. I don’t know what other credentials he needs to prove that he is conscious, and that he reasons and feels much like I do.

In my own view, I don’t need such evidence on a species before I am willing to grant them consciousness and admit them to my special club of special species. I would rather assume that all species have consciousness, and let you prove they don’t. I can’t imagine that the Great Inventor of Life sat in her chair and hand-picked who’d have consciousness. I could believe that many drivers on the road are not conscious.

I could believe that any organism that doesn’t have REM or RAM (Rapid Antennal Movement) sleep might not have consciousness, but I wouldn’t care too much whether this was true. In this book, we are talking about horses.

Doctors have come up with a scale for assessing degree of consciousness in humans. “Consciousness is assessed by observing a patient’s arousal and responsiveness, and can be seen as a continuum of states ranging from full alertness and comprehension, through disorientation, delirium, loss of meaningful communication, and finally loss of movement in response to painful stimuli.4” So where would your horse stand on this scale? When he is awake and at play, I’d give him top marks for “full alertness and comprehension.” And for that matter, I’d be willing to give all animals a similar score when they are active.

I hope you are on board for believing that horses have consciousness, that they have moods, that they are sometimes aware of their moods, and sometimes know the causes. I can imagine that when a thug with a crop enters a pasture and all the horses scatter, that they are all experiencing similar emotions, and that they are very clear on what has caused them.

I can imagine that what an octopus visualizes when it is dreaming is different than what I visualize, and that its consciousness has its own special interests. I can imagine that what makes a honeybee happy is a bit different than what makes me happy, but I can’t imagine how a honeybee would go through life without happiness.

It is not charitable to grant consciousness to other life. It is sensible.

What we need to do to learn about mood and emotion in other animals is to develop measurable neural, behavioral, and physiological indicators of emotion, and develop means of creating particular emotions, such as fear or anger.


In everyday language, we don’t distinguish between pain and suffering. We don’t distinguish between the experience of pain and the feeling of pain. But for hairsplitters, there are important differences. Hairsplitters tell us that pain can be experienced by animals that lack consciousness, but only those with consciousness can suffer and feel. Without consciousness, they can have pain, but not feel it. So their idea of feeling pain hinges on whether an animal is conscious. The debate has raged and will not be resolved.5 But I think this is preposterous. These philosophers (they are not biologists!) think that they can drop a layer of words down on the planet, then use those words to carve things up.

Sentience is the capacity to feel, perceive, or experience subjectively. Any species that can suffer, can feel pain, is sentient. We don’t need to get into a knot over the meaning of some word. For now, I’ll use pain as if it always implied suffering, and not go looking for how much consciousness the animal is experiencing. I believe that any species that is capable of motion is likely capable of making an effort to avoid injury, and thus is likely capable of experiencing pain and suffering. I am not interested in adding “sentience” to my vocabulary — or counting angels.

Pain is a fundamental of learning, of adapting, and of survival of both an individual and a species. Pain is not good. It hurts. But pain is useful: it is a quick teacher. Pleasure is the other fundamental of learning, of adapting, and of survival of both an individual and a species. Pleasure is good. It feels good. And pleasure is useful: it is a quick teacher.

Fish and horses are not exactly like us. But those who think that our reaction to pain is part of what separates man and beast are wrong. It is one of the things that binds us together. As a warning of trouble — hot, cold, sharp, crushing — it has guided all animals since they first had a choice of which way to travel. In a shared sentience, fish and horses are exactly like us.

Just exactly what does pain or pleasure feel like to a fish or horse? We can’t know. You can’t even know what pain or pleasure feels like to me.

But what we can know is that, in all species, pain must be unpleasant and that pleasure must be pleasant. As a surrogate for the injury, pain must be a state that the critter chooses to avoid. Because animal response to injurious sources is graduated, becoming more intense as the intensity of the source increases, we can also know that a lot of pain must be more unpleasant than a little pain.

And we can know that, in all species, pleasure is grand. As a reward for having done something right and beneficial, it is a state that the critter chooses, and enables learning. We can also imagine that a lot of pleasure is preferable to a little pleasure.

Do we need to know anything else?


1 Image source:

2 Wikipedia. “Consciousness”

3 Alderton, David. Animal Grief-How Animals Mourn. Veloce Publishing Ltd, 2011.; Bekoff, Marc. “Animal Emotions: Exploring Passionate Natures: Current interdisciplinary research provides compelling evidence that many animals experience such emotions as joy, fear, love, despair, and grief—we are not alone.” BioScience 50, no. 10 (2000): 861-870.; Bekoff, Marc. “Grief in animals: It’s arrogant to think we’re theonly animals who mourn.” Psychology Today. Oct 29, 2009.; King, Barbara J. How animals grieve. University of Chicago Press, 2013.; Brooks Pribac, Teja. “Animal Grief.” Animal Studies Journal 2, no. 2 (2013): 67-90.

4 Wikipedia. “Consciousness”

5 Wemelsfelder F. 1997 The scientific validity of subjective concepts in models of animal welfare. Appl. Anim. Behav. Sci.53, 75–88. ; Macphail E. M. 1998 The evolution of consciousness. Oxford, UK: Oxford University Press.; Baars B. J. 2001 There are no known differences in brain mechanisms of consciousness between humans and other mammals. Anim. Welfare 10, S31–S40.; Rolls E. T. 2005 Emotion explained. Oxford, UK: Oxford University Press.


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