First version: Jan. 2016 / Updated: Aug. 2017
All the arguments are used to recognize sentience are based on some kind of “similarity” or “closeness” with oneself: same aspect, same behavior, genetic / evolutionary similarity or closeness, same utility, same necessity. All are “alike”. This is how we recognize, in fact, sentience in other beings. Why do we do it like this? The answer is in the “Street light effect”. We do so because we can do so. If we have lost the keys in the street, at night, first we look for them where there is light, because where there is light, we can see. This does not mean that underneath the streetlight is the most likely place where the keys are. Instead, under the streetlight it is the most likely place where we can find the keys.
What is sentience? And who are the beings who feel? This matter has an urgent importance since we are able to be considered with animals, and since we are close to creating sentience in machines. That is, we are close to creating somehow “sentient animals” from scratch -non evolutionary-.
The first approach is practical and short-term. I need to use, today, now, the best of interpretations that I have to identify who are the beings that feel and be able to consider them morally. To be fair to them.
The best answer I have is that animals with central nervous system, that is to say with some type of “brain” (they can be several brains, and they do not have to be very big), are the beings that feel. And that the intensity with which they are able to feel is proportional to the typical complexity of their ability to react to the reward and punishment system that sentience is.
That is, I believe that certain types of beings (for example, certain species) are typically able to feel much more pain or pleasure depending on the difference that can be assumed that motivation in achieving intrinsic goals (evolutionary) which directed the construction of that being, which are the conservation of life and the reproduction of the species (the reproduction of genes).
I start from the assumption that in evolution, the species managed to acquire initial sentience in a very tenuous way, and from that moment the species evolved acquiring more and more sentience.
If particular species, when suffering more, endeavored more to conserve life and reproduce (and were more succesfully for this reason), it is plausible that this species evolved acquiring more sentience. And with pleasure happens the same, the only difference being that pleasure is adequate to motivate to do something concrete and pain is appropriate to motivate avoid something concrete one.
If, on the other hand, for such a species, an evolutionary context arises in which greater pleasure and pain were a useless to solve the problems, the acquisition of sentience would stop evolutionarily and even regress. If pleasure and / or pain were irrelevant to solving problems, the sentience would be arbitrary. There could be or not, much or little.
Review of the basics of reflection on sentience
This first approximation of the subject is the one that I use personally. However, under the second approach I propose in this matter, the above approach is based on some fundamentals that are not entirely sound.
In my opinion, the scientific advance of the last centuries, which has produced an impressive technological advance, is built on a philosophical system with great deficiencies and opportunities for improvement.
Until we have taken a serious stance on the issue of sentience, the shortcomings of our scientific philosophy system have not proved to be a big problem because of the kind of things we have been interested to investigate so far, which have been material things and ideas.
But now we are in a different context. We are able to have moral consideration on non-human animals and machines. We must give the correct answer to the question about who feels, and for this it is necessary to rethink the foundations of thought.
I ask the reader to have a little patience to endure this small incursion into the nature of reality. I think it’s necessary: a lot of people ask, “Is insects’ sentience proven?” Assuming that science will sooner or later offer incontrovertible evidence of whether or not something is sentient, as well as predictions of the movement of the stars. But no. Not in the current state of science and scientific philosophy. Sometimes, to make new things, we need new tools. The scientific approach to the issue of the sentience requires some fundamental (philosophical) aspects of the obtaining of evidence, on which there is still much disagreement and terminological problems.
I will talk about three types of concepts: matter, ideas and experiences.
No one can deny that at least from a descriptive point of view, these are different types of things. Nothing has to do with the “kind of thing” of a gold gram, prime numbers, or headache.
They are wrong. The statement is false. However, there is some truth in it, and perhaps what happens is that we have a terminological problem.
The phrase “there is only matter” is false, but it has an extraordinary resemblance to what actually happens, except for a very relevant factor.
The only world of which we have knowledge is the sentience one (world of experience). I do feel. I experience countless things. And that experiences are all that I can access directly. ” I do feel” is the only truth we are completely sure of. Despising this argument calling solipsistic and saying he does not get us any way, it’s a fallacy of the type argumentum ad consequentiam. The fact is that an uncomfortable truth does not make it any less true. The truth is that all I have is my own point of view.
The scientist points the apple on the table and says that it is a real object, and then points with his finger to his own head and says “How does my brain manages to represent this real apple in my mind?”
This approach is totally wrong.
That thing I point out, it’s no real apple: It’s the representation my mind has of the apple. Now I point to my head. That’s not my head. That is the mental representation that my mind has of my head. Now I leave home. I see the field, the trees, the moon and the stars. I open my arms, look around and say “all this, it’s my mind”. That’s right. What we call the universe is my mind.
If there is any doubt, people who suffer an amputation usually complain of pain in the limb that no longer exists. What we call “my right foot” is a mental representation in the brain. The shoe too. The universe too.
This is the uncomfortable truth that most scientists do not want to acknowledge, since it shakes their whole system of thought and therefore seems to “lead to nothing”, as it complicates dramatically any progress.
It is time to stop complaining and assume reality.
What then happens to the other two worlds, the material and the ideas? Do they exist or not? We can say yes or no, with these nuances:
If we say that there are three worlds is because we experience the existence of three different types of things: matter, ideas and sensations. But all three are experiences. Because they are so different, we say that they are three worlds. Agree.
If we say that there is only one world, that world is that of the sentience (world of experiences). Everything we call matter is the experience of something we call matter. Everything we call information or ideas is the experience of something we call information or ideas. Every particle of matter of which we have knowledge is really the experience of having knowledge of that particle. In order not to repeat ourselves and not to extend the expressions, instead of saying, “I experience the existence of that hydrogen atom” we can simplify by saying “that atom of hydrogen exists”.
Next I will analyze the answer to the question on how to recognize the sentience, taking into account the previous reflexion.
Who feels? And how to recognize it?
In my opinion, we recognize sentience through a series of mechanisms that I will enumerate below.
- I do feel
- Similar appearance
- Similar behavior
- Same (evolutionary) origin
- Genetic proximity
- Evolutionary utility
Maximum evidence: [1.] I do feel
“I feel, therefore I exist”
How to recognize which beings experience pleasure and pain? Let’s start with the basics. My own ability to experience feelings is a fact. Everything else can be considered a more or less reliable hypothesis.
“I feel”. Each of us has absolute certainty about our own ability to experience pleasure and pain. “I feel” is evident. Or could it not be? What if the sentience was an illusion? After all, what is “I”? What if the “I” were an illusion?
The “I” seems a dynamic, continuous concept: we call “I” to that which goes from my conception to my death. However, the “I” is “now”: My “I” of fifteen or forty years ago is as foreign to me as a close relative. He could see me and not recognize me, like someone who sees an old photograph of himself.
What if all my memories of past pleasures and pains were false? That’s the D5 hypothesis on the map of existential alternatives to the sentient experience. What if, besides, right now, I did not feel anything at all?
While it may seem that I do not do it all the time (to feel), rather, what happens is that I am not continually aware (or rather, I am not fully aware) of experiencing any sensation. Most of the time, fortunately, I do not think about it (or think of anything other than my own feelings).
If at the time of reading this text, the reader is feeling some kind of pleasure or pain, there is the “I feel” proof. Otherwise, you can make some sensation aware of how tenuous it may be. For example, focus on the act of eating or breathing (as a pleasurable activity) or on some part of the body that annoys even minimally.
In short, regardless of what we understand to be “I”, and even regardless of whether we consider “I” to be some kind of “illusion”, there is a “someone” who feels (a subjectivity: I), and that is a fact.
We have already found the first individual to feel: “I”. Let’s continue
Interpolation between individuals: [2.] Similar appearance and [3.] Similar behavior
“If he looks like me and behaves like me, he will feel like me”
We have said that “I feel” and that I am completely sure of it. I have many features or aspects that could describe me. Imagine that we make a list of my characteristics. Among them will be my ability to feel pleasure and pain.
Now suppose I meet another being who is similar to me. Through my senses I can capture many characteristics of this other being. Will it feel pleasure and pain? As I find more and more coincident characteristics between that being and I, I might consider that other characteristics of which I have no knowledge will probably also coincide. This reasoning has all the more weight as more similarities find between that being and me.
As an analogy: we can also list all the characteristics of the planet Earth, and in the case of finding another planet for which all the characteristics that we identify turn out to be similar to those of Earth, we could conclude that other new features still hidden will be more probably similar to those of Earth that if the rest of the previous characteristics had not coincided.
It seems to me that this reasoning, which resembles mathematical interpolation and the inductive method, makes sense. If certain characteristics that we see are coincident, it is probable that others that we do not see are also coincident.
If I had grown up between nonhuman animals and had never seen another human being and suddenly saw one, I would be impressed by the number of similarities he has with me, and as I encountered similarities without stopping, I would suppose that other hidden features will also have a high probability.
Alas, it’s true that all this alone does not offer great confidence. The planet we discover could obviously give us many surprises. And like the young character Mowgli in fiction “The Jungle Book” when he met the first human, the beautiful Shanti, the similarities do not provide security in certain important features: she’s a girl.
However, we will be able to increase our confidence in the other person’s feeling of having precisely that aspect and behavior that in my case is associated (there is a correlation) with my own ability to feel, and more, if it is before receiving the same stimuli.
For example, he not only looks scared and does the same gestures and movements that I do when I am scared: it is that he also does them after receiving the same stimuli that frighten me.
When this combination is given, we are even more likely to assign more probability to the subjective experience of the other.
However, other possibilities remain open:
- That the other beings do not feel, even though they are of similar appearance and behaving similarly to the same stimuli. We must admit it as possible, but very unlikely: the result of deliberate deception or great coincidence.
- That other beings also feel, even if they are not alike, even if they do not have similar behaviors, even though what stimulates them is totally different from what stimulates me.
This second possibility is much more likely than the previous one. We must recognize the risk that is happening here something like the anthropic principle, what I call “The street light effect”. if I go down the street at night and I lose my car keys, I first look under the lamppost. Why? Because there is more light there.
To assign more likely to the sentient experience to beings more like us is correct, but it seems to me somewhat unfair to beings who are very different. If an ant would do the same reflections, it might conclude that an aphid is surely as sentient as an ant. And humans and bears could be considered not sentient, being too large, or even not consider even “beings” but rather “phenomena”.
It seems to me honest to recognize that there may be “beings” greater than we humans whom we consider “phenomena” and if a gradualist sentiocentrism inclines us to think that the ant is sentient, but less than us, this analogy should make us recognize the possibility of the existence of beings much more sentient than us, whose nature we do not understand well. This is the case of the A11 and C2.2 positions of the map of existential alternatives to the sentient experience.
How to further refine the odds? Like when we interpolate values in a mathematical series, knowing the meaning of the series will be very helpful in assigning probabilities to the interpolated values. That is to say, I am interested in knowing more about that other individual who seems to me. The relevant question now is this: “Why does he look like me?”
Interpolation between species: [4.] Same (evolutionary) origin and [5.] Genetic proximity
“If it has been created like me, it will feel as I do”
If two things are similar, it is reasonable to consider the possibility that they have the same origin, that they were created from the same “mold”.
Fortunately, we have good theories about who we are and where we come from living beings, and from among them, animals, and among them, humans, and among them, I. And we also have good theories about the origin of the planets.
The theory of evolution is a good explanation of our origin (that of living beings, that of animals, that of humans, mine).
The theory of evolution manages the concept of species, which, although a somewhat diffuse concept, with no well-defined limits, serves to identify many beings whose appearance and behavior is similar to mine, as “like me” to belong to the same species (mine).
In addition, the theory of evolution includes the concept of genetic proximity. Genomics gives us clues about whether such are evolutionarily closer to the cow mouse.
So if to the argument of “similar appearance and similar behavior”, I add the argument of belonging to the same species (because of the same evolutionary origin) or belonging to a different species, but relatively evolutionarily/genetically closer, I’ll be more confident about the capacity to feel of that other being.
This is therefore a mechanism to recognize the sentience, complementary to the previous one and based on similarities (“neighborhoods”) between species. In summary: since I feel, and I have a good theory about my own origin, I think that other beings with evolutionary origin (and similar evolutionary origin), and even more if they are closer (more similar) to me, genetically speaking.
Utility or need: [6.] Evolutionary utility
“Evolution is testing things and stays with those that serve for something”
So far we have presupposed the sentience in beings similar to me, either seem more obvious (aspect, behavior) or less obvious (evolutionary origin and genetic proximity). By reasoning similar to interpolation or induction, I establish a general rule from particular cases. In the first case (“Similar appearance and similar behavior”) from particular cases of properties of type “appearance” and “behavior” that resemble mine, I establish a general rule, presupposing another property, the sentience, in said individual. In the second case (“Evolutionary origin and Genetic proximity”) I included the theory of evolution and apply a similar reasoning to the previous one, also based on closeness and resemblance, but instead of applying it interpolating properties between individuals as I have done in the first case, in this second case I apply it by interpolating properties between species, taking into account the different possibilities in relation to the origin of both individuals (me and the other), so that, for example, if the species of the other is similar (close) to mine, I suppose it will feel in a similar way to mine, and it will feel more similar as i as it’s species is more similar / closer to mine.
As we apply these techniques to identify the sentience in other individuals, we can find a series of coincident aspects, a sort of correlations: the individuals I call sentient have eyes, have a brain, show intelligent behavior, seem self-conscious, they can recognize themselves in a mirror, etc.
Now we will see that we do not even need to be similar or “close” in appearance or in kind. It is enough to be “like” or “close” as to the usefulness of sentience.
Let’s go one step further and use the theory of evolution again, deepening the reason for the sentience: is it useful? good for something? It is very possible that it is. Assuming this hypothesis (very popular) we could consider that in the case of all the types of beings for whom the sentience could be relevant, it has been selected evolutionarily, and therefore they are sentient.
This is the case with the octopus, which is a very intelligent being, we consider it very sentient and yet it is very different from us, in terms of appearance, behavior and evolutionary distance.
Critical appraisal of arguments
All the mentioned arguments are based on some kind of “similarity” or “closeness”: same central nervous system, same aspect, same behavior, similarity or genetic / evolutionary closeness, same utility, same necessity. All are “alike”.
This is how we recognize, in fact, the sentience in other beings: through resemblance. Why do we do it like this? The answer is in the “Street light effect”. We do so because we can do so. We seek the keys where there is light, because where there is light, we can see. This does not mean that underneath the streetlight is the most likely place where the keys are. Instead, under the streetlight it is the most likely place where we can find the keys.
With the arguments I have set forth, we reasonably demonstrate the existence of the sentience of certain beings, but we do not demonstrate the non-sentience of the rest of beings. It is possible that in the future we will find new evidences of existence of sentience that have nothing to do with the present ones, and that perhaps they are not based on the “similarity”. This is why it seems to me so important to anticipate all possibilities of sentience on the map, even though most of them currently seem to us unjustified and even ridiculous.
Critical to the requirement of the central nervous system
In relation to the requirement of “having brains” for there to be sentience, mentioned in the first part (“Practical approach”), something curious happens. The brain is a nervous, neuronal, large mass. It seems that the bigger the neuronal mass, and the more centralized, the more sentience. That is, the typical number of neurons in each species is relevant, or at least the ratio between brain size and body size, to estimate the potential capacity of typical sentience of individuals of that species. But the brain does not hurt. It has no pain receptors. Where is the pain then? Where is the sentience? What I want to emphasize here are two things, on the one hand, once again, that the sentience has an existence independent of the material world; and on the other hand, that when we speak of “central nervous system” as a requirement of sentience, proponents of this proposal actually refer to a complete nervous system, which also has a centralized nervous system.
Usually the advocates of the central nervous system argument assume that “in the absence of at least one central nervous system, consciousness does not arise“. That is, if a being has no brain, it does not feel. But I think the argument should be the other way round: if there is an operating centralized nervous system, we can fairly safely state that there is a sentience / consciousness there. But if there is no centralized nervous system, we can’t ensure that there is no such sentience.
An argument that seems definitive to argue that the central nervous system is necessary for consciousness is that if we introduce something into that central nervous system that “disables” it (eg, anesthesia before an operation), we lose consciousness and we do not feel nothing. I believe that this is so (except for exceptions: for example we could imagine an anesthesia that would immobilize the body and cancel the memories, but it would not prevent the pain; after the intervention, the patients would say that they have not suffered anything, when what happens is they don’t remember it). However, saying that “without a central nervous system there is no consciousness” I think a hasty generalization. It is true about we: if we disable our central nervous system, we lose consciousness. But other beings could acquire consciousness in other ways. Making a metaphor between “feel” and “fly”: if a bird wet its feathers, it loses its ability to fly or this is greatly diminished. But planes and rockets also fly, even with rain. Airplanes do not have feathers and the rockets do not even have wings. And they fly. That we acquire sentience through our central nervous system does not prevent other beings from acquiring their sentience in other ways.
Critical to the argument of evolutionary utility
It is generally assumed that pleasure and pain have an evolutionary origin or an evolutionary explanation, since they produce motivation to achieve objectives related to the perpetuation of genes, and this motivation is useful. When you think like this, it is also often thought that without an evolutionary context you can’t generate the feeling. I will make three criticisms of this idea.
- Indeed, if the consciousness were evolutionarily useful, sentient beings would be selected. But let us also take into account that if the sentience were indifferent from the adaptive point of view, it could also exist. Hypotheses that sound crazy, as to say that atoms feel a continuous pleasure or a continuous pain; or they feel one or other depending on certain physical properties, for example, they feel pleasure when approaching, and pain when moving away from each other, are perfectly compatible with the evolutionary argument.
- On the other hand we must recognize that even supposing that the sentience produced a greater motivation, and the greater motivation produced a greater aptitude, there are many cases in which this is not so. For humans there has been an evolutionary context in which compared to other mechanisms, greater pleasure and pain have lost effectiveness and efficiency in solving problems. Pain is useful in many cases, but in others it is not. That is why, in addition to other reasons, we have developed anesthesia.. Fortunately we have the ability to direct all our efforts to stay with pleasure and happiness that we have obtained of evolution, and completely eliminate pain and suffering, for us and for other animal species.
- Third, and this is the most important thing, the claim that “pleasure and pain have an evolutionary origin” seems to me precipitous because it introduces into the theory of evolution a strange element, which nature is totally different from the elements of the theory of evolution, without explaining where it comes from. I do not deny this hypothesis, it seems to me possible. But I think it requires more thought. It seems to explain more than it explains.
I will explain this last point more. Evolution occurs when there are certain basic elements (of information) that are combined and copied with errors in a context of scarcity. The claim that sentience is a consequence of evolution because it is useful for individuals seems a petitio principii fallacy, as follows:
- Premise: When purchasing sentience, animals are favored in fitness.
- Conclusion: Sentience is (just) the result of evolution.
The conclusion is contained in the premise, since both mean the same thing. I know that for many readers this will be shocking, because there are plenty of examples in which this type of reasoning is valid. For example, it seems correct:
- Premise: When acquiring eyes, animals are favored in aptitude.
- Conclusion: Eyes are the result of evolution.
- Premise: When acquiring wings, the animals are favored in aptitude.
- Conclusion: Wings are the result of evolution.
However, aircraft also have wings, and these wings are not the result of evolution, but an intentional intelligent design. Computers have cameras, which function as “eyes”, also resulting from an intentional design. I do not pretend to defend here the idea that animals have gained consciousness from an intentional design (which, moreover, is perfectly possible), but on the contrary, that objects created with an intentional design (robots) can also become aware.
From a strictly materialistic point of view, evolution does not exist, nor do individuals, wings, or eyes exist. From a strictly materialistic point of view there are only atoms, particles, energy, electromagnetism… that sort of things. Of course when we mention words like “atoms” or “particles” we are talking about ideas (the idea of “atom”, the idea of “particle”) because when we communicate in written or spoken form, what we communicate are ideas, but in doing so we do not refer to the ideas themselves, but to the material objects they represent.
The theory of evolution deals with ideas such as “gene”, “individual”, “species”, “feathers”, “eyes” or “fly” to explain the behavior of matter. Speaking of “eyes”, “feathers” or “flying” is a way of describing in a summarized way the behavior of matter. But sentience is a type of thing totally different to “eyes” or “to fly”.
Criticism to the argument of the emergency
When the above arguments we add the aspect of the emergence of consciousness, we find the same petitio principii fallacy combined with a falacia ad consequentiam of positive type, in which assert that something is simply true because its consequences are positive, in this case, for the perpetuation of the genes. The fallacy is as follows:
- Premise: sentience emerges from the animal matter.
- While acquiring sentience, animals are favored evolutionarily.
- Therefore, the premise is true.
Even accepting that animals could be favored by the sentience, this does not necessarily imply that the sentience is something emergent. Sentience could be otherwise. For example, instead of a emergentist sentience, there may be a immersionist sentience.
Many say that “Matter creates the sentience” or that “Sentience emerges from matter”. The phrase has been condensed. What the phrase really means is “I have absolute confidence that matter exists, and a reasonable confidence that matter is what creates consciousness.” But this is not the case, it is just the opposite: I have absolute confidence that subjectivity exists, and subjectivity gives me reasonable confidence in the existence of a material world. Sentience is a fact, matter is a hypothesis that emerges from sentience.
These criticisms make me think that consciousness / sentience can be much more available / easier to produce than it seems. Every object could be somewhat conscious / sentient, even atoms.
If we continue to insist that pleasure and pain have an evolutionary origin or an evolutionary explanation “and that’s all”, then we must also assume that probably pleasure and pain (and / or the will and / or identity) are some of these basic elements, in some way “pre-existing” that they are participating in the evolutionary process, and that any information-based system can become aware. That is, for example, we can create on a computer, in a “artificial” way (simulated molecules) all elements of the natural evolution as we know it, based on molecules: recombinations and copies with errors in a context of scarcity (= evolution) . If we assume that in the material world consciousness arises because of the evolution of these elements, and that’s all, it would be inconsistent to consider that in this simulation sentience does not occur.
In short, the popular idea of the emergence of consciousness only in animals is precipitated, plus if it is considered that sentience does not occur on machines or in simulations, is incoherent.
So I think the concept of antispeciesism is not enough. An “antisubstratism” is necessary. The key to “humanism” of the future (I mean compassion, moral, empathy) is the anti-substratism. No matter if the substrate that generates sentience is material or not. No matter the species, no matter animal or mineral, wet or dry, animal, robot or simulation… or mixed situations… if there is sentience, interests, preferences… then there is an individual and moral relevance arises: that individual deserves moral consideration.
|What is Anti-substratism?
“Antisubstratism” is equivalent to “Antispeciesism”, referred in this case to the idea of substrate instead of to the idea of species. It is unjustified to discriminate morally according to the substratum that supports the conscience (understood in this case as the capacity to feel, to have interests), just as it is unjustified to discriminate morally according to species (speciesism), race (racism), sex (sexism), etc.
How does it work the mechanism that ignores the sentience of non-human animals?
So far I have explained in several steps how the mechanism that recognizes the sentience in other beings works. It is clear that this mechanism allows us to recognize the presence in many non-human animals. However many humans (most, in fact) systematically ignore the consciousness of infinity of animals. How is this possible? In this article I explore some possible reasons.
A summarize and final reflection
- How do we recognize the sentience? By similarity or surround.
- Why? Because it is the way we can do it easily, according to the “Street light effect”. But this does not mean that it is the best way to do it.
- How should we recognize sentience? The priority should be to recognize the sentiences of the beings who suffer the most.
- Why? Because those who suffer the most are those who most need our moral consideration.
Additionally, and taking into account that:
- the source of moral consideration is evolution, and
- evolution is a particular case of a manifestation which could be described as the tendency of things towards stability, inertia or recurrence, which
- responds to our way of observing and conceptualizing reality,
then, our moral consideration could be unfairly limited to objects that we are able to identify.
The “principle of stability, inertia and recurrence” was first published in 2002 in the journal REDcientífica in this direction (now inaccessible):
now available in this new direction:
and in the book “Arena Sensible”
The principle has been cited in:
About the article
I started writing this article started in a way as a replica to the following article with the same theme in “Animal Ethics”:
Animal Ethics identifies three types of criteria for recognizing sentience, which are (1) behavioral, (2) evolutionary, and (3) physiological. I agree with those criteria. Here in my article I intend to complete some aspects that I consider relevant as to how these criteria have emerged and why we chose them. I consider that all criteria are based on one or another form in the proximity or similarity. The question “what are the criteria?” is what answers the article of Animal Ethics. The next questions I think we should ask ourselves are “why?”; “What should they be?” And “why?”, And that is what I am trying to start to answer in this article , which I feel is still incomplete.
The key to recognizing the ability to feel (the sentience) will, of course, depend on what we consider to “feel.” It seems logical to first define “sentience” or “consciousness” and then talk about how to recognize that sentience. This article was originally titled “What is Sentience and How to Recognize It?” But I preferred to separate it in two. The definitions of sentience and subjectivity (consciousness) I have finally left in this other article: