» November 1st, 2014

I just finished a challenging but deeply edifying book called Consciousness: Confessions of a Romantic Reductionist, by Cal Tech biologist Kristof Koch.  The book is the finest example of making hard science accessible without dumbing it down that I’ve encountered in some of the modest reading I’m doing on the physical basis of consciousness. My underlying goal is to get a sense of what the most knowledgeable experts on the brain have to say about the connection between neurological sophistication and consciousness.

Koch, for one, certainly posits a correlation. He writes, “Consider simpler animals—simplicity measured by the number of neurons and their interconnections—such as mice, herrings, or flies. Their behavior is less differentiated and more stereotyped than that of dogs. It is thus not unreasonable to assume that conscious states of these animals are less rich, filled with far fewer associations and meanings, than canine consciousness.”

I know this line of thought makes some animal rights advocates, many of whom prefer to view all animal life as deserving the same moral consideration, nervous. But I like the proposition in part because neurological complexity is the same physical basis that biologists use to distinguish a category of life that we do not grant equal moral consideration:  plants. This distinction is one that animal rights advocates very much need to preserve at all costs. Consider this excellent overview of the plant/animal distinction on the basis of evolutionary cellular development by Oliver Sacks:

The calcium ion channels that plants rely on do not support rapid or repetitive signaling between cells; once a plant action potential is generated, it cannot be repeated at a fast enough rate to allow, for example, the speed with which a worm ‘dashes … into its burrow.’ Speed requires ions and ion channels that can open and close in a matter of milliseconds, allowing hundreds of action potentials to be generated in a second. The magic ions, here, are sodium and potassium ions, which enabled the development of rapidly reacting muscle cells, nerve cells, and neuromodulation at synapses. These made possible organisms [i.e., animals] that could learn, profit by experience, judge, act, and finally think.

The proposition of a continuum of consciousness based on neurological complexity does not necessarily mean that humans will use that continuum as a justification to abuse animals with nervous systems that are nominally less complex. Curious about Koch’s stance on this issue, I poked around the Web. In an interview with Scientific American, he was asked if his research influenced his own behavior. I put a fist in the air when he explained, “I have stopped eating the flesh of mammals and birds, as they too share the wonders of experience with us.”

In this respect, I think the pursuit of a physical understanding of consciousness—even if we never uncover it—can be a benefit for animals. That is, as humans begin to understand that the nature of existence originates and is sustained exclusively by measurable physical forces, the less we will seek answers to our existence and its meaning in traditional spiritual frameworks that impose unfounded hierarchies that arbitrarily favor human exceptionalism over “brute creatures.”

That catch, of course, is that to pursue the quest for consciousness, scientists seem to think that the only way to do so is to experiment on the animals their findings suggest have qualities that demand our respect and moral consideration. Therein lies a conundrum I hope to address soon.

13 Responses to Consciousness

  1. Rucio says:

    Moral consideration that relies on the resemblance of a being to oneself would not seem to be very deep.

    It may turn a few people away from eating other vertebrate animals, but it’s a shaky foundation to build on. After all, humans easily rationalize brutality towards other humans. The hierarchic ladder of being is an easily manipulated fallacy.

  2. Norm Phelps says:

    The idea of a continuum of consciousness is not so much wrong as it is substantively meaningless and morally irrelevant. It is substantively meaningless because consciousness is an entirely subjective phenomenon; therefore, no objective scale by which the consciousnesses of different individuals (much less members of different species) could be compared can ever be established. Scales of comparison are meaningful only for the objects of consciousness, never for consciousness itself. To regard consciousness as though it were an object of consciousness is to make a category mistake by treating the purely subjective as if it were objective and proceeding as though we can experience another individual’s consciousness the way we experience colors or sounds when, in fact, we cannot—a point discussed most informatively by Thomas Nagel in his celebrated essay “What Is It Like to Be a Bat?”

    Individuals can be said (with some limited degree of meaningfulness and reliability) to possess a lesser degree of consciousness at one time (following a blow to the head, for example) than they possess at other times based on their descriptions of their own subjective experience, but an outside observer can never evaluate the consciousness of another being (including another human being) because s/he can never experience another being’s consciousness, and indirect inference tells us nothing about the subjective experience of the being whose consciousness is being evaluated. This is what makes decisions about how to treat persons in comas so fraught. The fact that the ghost is largely (but usually not entirely) disconnected from the machine does not necessarily mean that the subjective experience of consciousness has vanished or even diminished. We cannot infer the subjective quality of consciousness from objective indicators, like neural complexity, without adopting the reductionist view that consciousness is a byproduct of neural architecture, a proposition for which there is no evidence and which is neither testable nor falsifiable because, as I have already noted, there is no way to compare purely subjective phenomena. “To a person whose only tool is a hammer, every problem looks like a nail.” The scientific method can investigate only the material world—i.e. objective phenomena—therefore, those who believe that science is our only legitimate source of knowledge are forced to the belief that consciousness is a “byproduct” (whatever that means) of physical phenomena.

    Even more to the point, a purported continuum of consciousness is morally irrelevant because everyone’s consciousness is of ultimate importance to them. Our consciousness is our life, it is our very self, it is everything we have—no matter where it might stand on somebody’s “continuum.” My consciousness—no matter how “complex” or “simple” it might seem to someone else to be—is of supreme value to me, just as yours is to you, and just as the cow’s, chicken’s, earthworm’s, and flea’s are to them. And it is for this reason that all consciousness must be accorded equal moral weight and all conscious beings must be accorded equal moral consideration. Ethically, consciousness is an all or nothing proposition. Either one has it, like animals, or one does not, like plants and minerals. This, in fact, is the significance of Oliver Koch’s comment; it is an acknowledgment that animals have consciousness, and this acknowledgment is not at all dependent upon any kind of continuum or scale, or belief in consciousness as a byproduct of physiology.

    In its practical effect, if not always in its intent, the notion of a continuum of consciousness is a rearguard action to preserve in some measure the discredited concept of human exceptionalism, and it will invariably end up being used to defend the exploitation and oppression of nonhuman animals.

    • James says:

      This is a great response. Thank you for it.

      • Norm Phelps says:

        Thank you. I’m a fan of your work, especially “Just Food.” And as a former employee of HSUS and a supporter of welfare reforms pursued in the context of a campaign against all animal exploitation, I thought your post on “Hoofin’ It” was perfect. I’ve pre-ordered “The Modern Savage” and can’t wait to read it. Incidentally, in my comment I said, “Oliver Koch” when I meant “Kristof Koch.” My apologies.

    • Taylor says:

      Norm: If not objective indicators, what is it that makes you believe that all animals, and only animals, are conscious? A quick googling reveals that sponges are animals without even nervous systems, much less brains. Should I give equal moral weight to you and a sponge trapped in a burning building on the assumption that the sponge has a consciousness that is of supreme value to it? (Quick, someone, lend me a coin!) If we are to be forbidden from appealing to objective indicators like neural architecture, isn’t denying that plants and minerals are conscious just another example of hierarchical anthropocentrism?

      You may be right that the notion of a continuum of degrees of consciousness will be used by some to try to preserve human domination, but that doesn’t disprove the existence of such a continuum — even if it does complicate the struggle for animal liberation.

  3. Norm Phelps says:

    I was using animals (a bit imprecisely) in its common language meaning as a term of convenience. The existence of some beings who are biologically classified as members of the animal kingdom, but that are not sentient does not affect my argument. Since sponges have no nervous system, it seems clear that they are not conscious. There is a qualitative difference between having no neural architecture and having some form of neural architecture. But there is only a quantitative difference among neural architectures of varying complexity–and there is no reason to assume that more complex architecture leads to a richer inner life.

    Recognizing the existence of consciousness is an entirely different matter from describing it or quantifying it on some scale. And the fact that we may sometimes be mistaken in attributing or denying consciousness to individuals (as in the case of people in a coma) or to members of a particular species does not invalidate the basic principle. There are three primary reasons for denying consciousness to plants and minerals while acknowledging it in (nearly all) animals: 1) behavior: plants and minerals give no behavioral evidence of sentience (galvanic response is an electro-chemical process, not a behavior), animals give considerable such evidence; 2) physiology: plants and minerals have no physical mechanism that we can recognize as capable of connecting the ghost to the machine; (nearly all) animals do; and 3) evolution: consciousness conveys an immense evolutionary advantage to beings who are able to act intentionally in their own self-interest (which includes most animals, although not sponges); it conveys no advantage to being who are not (plants and minerals).

    As a fundamental matter of epistemology, it is impossible to meaningfully compare the consciousness of different beings. And as a matter of ethics, such comparisons are irrelevant because the consciousness of every conscious being is of supreme importance to that being. Therefore, the life of every conscious being must be accorded equal value. This creates severe discomfort–in me as much as in anyone else–and under burden of necessity we cannot always treat other beings equally. (I will not let termites destroy my house, for instance.) But uncomfortable or not, I believe that honesty and morality require that we make our decisions about our relationship to and treatment of others with this fundamental moral equality firmly in mind.

    • Mountain says:

      I’m interested in the termite example. Not because it’s wrong, per se, to kill termites, but because so much of the harm we do (to plants and animals) results from the desire to make things “permanent.” Living structures could be constructed much less expensively, and much less environmentally harmful, if they were built with the understanding that nature (via termites or other) will take them back.

  4. Rhys Southan says:

    “[T]he consciousness of every conscious being is of supreme importance to that being. Therefore, the life of every conscious being must be accorded equal value.”

    Would you say that the life of every conscious being and *only* the life must be accorded equal value? Or must various aspects of quality of life be accorded equal value as well?

    “This creates severe discomfort–in me as much as in anyone else–and under burden of necessity we cannot always treat other beings equally. (I will not let termites destroy my house, for instance.)”

    What do you mean by necessity in this context? How is the preservation of your house necessary? If termites are conscious and we must accord all conscious lives equal value, wouldn’t killing them to protect your house be like killing hundreds of thousands of humans in defense of your home?

  5. Norm Phelps says:

    By “life,” I meant the inner life, the totality of the awareness of a being.

    I have discussed question of insects at some length in an article on my blog NormPhelps.Org, entitled “The Rights of Flies and Fleas.”

    • Taylor says:

      I think everyone here should read your well-argued piece “The Rights of Flies and Fleas”.

      To you it is obvious that insects are sentient, but to me this is not obvious. I suspect that for most people intuition is the starting point of their intellectual response, and different people have different intuitions on the matter. To me it’s always been obvious that a dog is a someone, but most bugs just look like little organic machines. Perhaps intuition is closely linked to anthropomorphizing here: it’s much harder for me to imagine myself as an insect.

      Readers should also follow the link in your essay to the Brian Tomasik article. After having put the probability for insect sentience at 40%, he revises this to say in a footnote: “I think sentience should be seen to come in gradations, in which case the question is less whether insects matter or not in a binary fashion but how much they matter. I think it’s very likely I would care to some degree about insects upon further reflection, but whether I would care a little or a lot remains uncertain. At the moment I would guess that I value preventing one dog from suffering at around the same as preventing ~100 insect[s] from suffering in an analogous way. This assessment is likely to change over time.”

      • unethical_and_speciesist_vegan says:

        I do not understand why there is a need to be dismissive of neuroscience. Neuroscience and ethology, for example, has suggested that some invertebrates are cognitively sophisticated (cephalopods and arachnids). To my knowledge, there is simply no evidence of pain perception in animals that lack sensory afferentsthat communicate with a “cephalized” central nervous system. Neuroscience has also shown that reflex behaviors and hebbian associative learning can be mediated by simple biochemical switches. Because these forms of “reflexive” learning have have been observed in the most primitive organisms, including bacteria, they should not be the basis of conjecture about sentience or consciousness. In a similar vein, the presence of nociceptory neurotransmitters is not evidence of pain conduction. Opiods, histamines, and other neuropeptides linked to nociception are found in single cell organisms and primitive multicellular animals (e.g. animals that lack nerves entirely). These compounds are biochemical signals and their presence is not evidence of cognition.

        I should also stress that consciousness “a la Koch” is not sentience. My goal as a veganish person is not to preserve minimal consciousness but to avoid causing unnecessary pain. And when it comes to pain, neuroscience can provide some bonafide insight. For example, there are animals and insects that unambiguously lack sensory nerve afferents that communicate with a CNS. If these animals are capable of *perceiving* pain, they are sentient via completely unknown mechanisms. An “unknown mechanisms” argument could be used to argue for the sentience of plants or fungi.

        Even the presence of ganglion connected to sensory nerve afferents does not necessary mean a thing is sentient. For example, a resected piece of human colon has a far more sophisticated “nervous system” than many primitive invertebrates. Are body parts sentient? Are early embryos sentient?

        And finally I should note that bed mites have a very small but intact central nervous system that is connected to sensory afferents. They are unambiguously more capable of sensory nerve conduction than many invertebrates that are commonly used as food sources (e.g. sessile molluscs and larvae/grubs). Nevertheless, I have never met a “vegan” who attempts to ease the “suffering” of bed mites via the use of synthetic bedding materials and daily cleaning of said bedding.

        I would like to finsh by pointing out that it is possible to create “food” insect lines that are genetically limited to the larval stage (e.g. never form a central nervous system). Likewise there are huge numbers of fly mutants that lack an intact nervous system. Thus, developmentally arrested or devolved transgenic insects could be used convert agricultural byproducts into nutrition. It’s hard to understand why a non-deontic vegan would be opposed to this — at least in theory.

  6. Karen Harris says:

    Check out a short video and article in today’s NY Times, “Unexpected Complexity Inside a Spider’s Tiny Brain.”
    Especially interesting in terms of the conundrum addressed in the last line of the blog relating to experimentation. Note that there is no reference to any kind of pain killer or acceptable protocol as a wire is inserted into the brain of the jumping spider.
    For the author, the spider resides far outside of the circle of compassion.
    Interesting comments and blog.
    Even if one agrees that any kind of hierarchical structure is necessarily anthropocentric and ultimately subjective, we still have to make choices. Just by dint of living and consuming we necessarily do harm.
    It is clear that as humans we favor other beings most like us and the first impulse is to give more weight to those lives – in other words, we save the dog in a burning house before the termite.
    Perhaps it is best to own that these choices are not ethical or moral at all, but nevertheless necessary and impossible to avoid.

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