Is it reasonable to believe that others have sentient minds?

Question

Obviously I'm not looking for a valid deductive proof using formal logic, but at least a relatively convincing argument.

How do I know that humans who I encounter other than myself have sentient minds, and aren't just unfeeling zombies?

It seems unreasonable to use the induction: "I am, in all observable ways, a human, and this human (me) is conscious, so all humans are conscious" or any from of that argument (such as, 'I know of this thing (me) that speaks about consciousness is conscious...) because I only know for certain of one such instance, and I'd never want to make a general induction from just one instance. (Imagine: "this person is a blue-eyed carpenter, so all people must be blue-eyed carpenters")

Is the fact that, from my own perspective, people act and speak as if they have conscious minds, enough for me to conclude that they are indeed conscious? Would it be unreasonable to conclude the opposite, that nobody posses a conscious mind besides for myself?

The only reason why I might be inclined to believe that other people have conscious minds is that I have a hard time believing in zombies, but if philosophical zombies are possible, than it seems more reasonable to conclude that other people are in fact zombies instead of attributing to them the added complexity of a conscious mind. Does anyone discuss the idea that belief in zombies might negate the belief in others' minds?

Related zombie questions: their existence, cognitive ability, and other implications. (There's no 'zombie' tag yet)

Answer 1

It is more complex and convoluted to explain why other human beings would present such an utterly convincing simulation of consciousness and sentience than to simply assume that they are conscious and sentient.

Answer 2

Asserting that "I have conscousness but no one else does" has a degree of implausibility similar to that of geocentrism: why, out of all of the (more or less) externally similar human beings does this one (me) have consciousness (i.e. a special place in the universe)?

Basically it's an assumption of uniformity of properties across the class of objects we call humans -- which is a more simple hypothesis that is consistent with all of our observations than the hypothesis that only one (or a small fraction) of humans are conscious. This can be seen as an empirical, scientific proof that (essentially) all humans are conscious.

In common usage, we can tell the difference between someone who is conscious and one who is not by whether they respond to stimuli, move around etc. Note that there are also what I would term as reduced forms of consciousness, e.g. people undergoing a stroke who are not fully aware of their surroundings or able to form memories etc. The main point is that we infer that their mental state is different from normal (or ours) because the resulting behaviour is so different. Different outcomes due to different causes. Conversely, as we interact with unimpared people, we see behaviours that are at least plausible given our mental states, and use the principle that similar outcomes came from similar underlying mental processes.

It's this assumption of uniformity, similar outcomes from similar causes, that is the logical weak point in this argument. However, it is not an unacceptable position in scientific thinking as long as there is no other evidence against it.

Answer 3

Analogy is one of Bertrand Russell's five postulates that validate scientific method. It states that "the behavior of other people is in many ways analogous to our own, and we suppose that it must have analogous causes." This is the postulate that the belief in the minds of others requires. (Source: Russell bertrand. _Human, Knowlege, Its scope and limits. New york: simmon and schuster, 1948)

Like all Russell's philosophical scrutiny, such a postulate only exposes doubt. On one occasion, Russell admitted that it would have been far easier for him to grow intimate with a cat or a dog or a horse than with one of the half-nomads he saw on the sand bank of the Volga.

In another writing, Russell suggests that "perhaps one could stretch the comprehensiveness that constitutes wisdom to include not only intellect but also feelings." He points out that "it is by no means uncommon to find men whose knowledge is wide but feelings are narrow." "Such men," he writes, "lack what I am calling wisdom." (Source: Russell, Bertrand. Portraits from memory. Knowledge and wisdom. New York: Simon and schuster, 1956)

Answer 4

It seems to me that you must assume other human beings are sentient, or explain why you consistently wish to subvert your own efforts. If you are the source of all willful action, and we are zombies, then you need a good reason for your own self-destructiveness when we compete with you or resist your will. If we do not have goals of our own, why would our actions so consistently defy yours?

Human action cannot be explained as a simple, mechanical process, or it would be much simpler -- it is goal directed and solves problems on purpose. Any reduction that would allow for us to be mere mechanisms, would reduce you to one as well.

You might suppose you and Satan (or Entropy or whatever equivalent is convenient) are the only two sentient beings around, and we are agents of his, but then you would need a good reason why he would not simply compete with you directly. The level of detail he needs to maintain to keep all of the zombies in convincing personality traits is a complete waste of effort he could deploy more effectively.

Assuming Satan is more independent of you than directly competitive does not help. If we are simply fragments of a single separate will, we are still separate from you, and will is not a uniform thing, so you might as well consider each of us, or each critical mass of us who seem to agree, a separate will, as to assume there is a single complex will involved. And even if I am an epiphenomenon of a deeper sentience, I embody sentience.

Answer 5

If you are asking for a foolproof answer to hard solipsism then you are out of luck, there isn't one. You may indeed be the only sentient brain in the universe and the rest of us are just figments of your deluded imagination.

That said, if you except that everyone else exists physically then you have to agree that the idea that of the 6.5 billion humans on the planet, you are the only one to develop a conscious mind (given we all share the same basic cranial hardware) is statistically very unlikely.

Answer 6

If it were the case that the "others" were indeed philosophical zombies, you wouldn't have found it worthwhile to ask "others" the question you posed. Surely, we might appear to enter this discussion, but why would you listen to us zombies who lack the experience that you can refer to while we cannot? Our answers might be even reasonable but wouldn't be convincing or relevant to you.

Answer 7

There is no logical proof, but there are good rational approximations of proofs. As has been mentioned before, Occhams' razor is an argument here: it's much simpler to assume that since others act like I do, look like me, etc. then they must be conscious, like me; than to assume that one way or another, they would look as if they were conscious, but actually aren't, because to assume this you would have to describe the "one way or another", and this would not be simple. There's also the idea that no particular person is special among others (well you can be extremely skillful at gymnastics, but others will be too). But one could say: it would be unreasonable to assume that others aren't conscious, but it would be illogical to assume otherwise.

Answer 8

One liner: If it looks like a duck, swims like a duck, walks like a duck and quacks like a duck then it must be a duck, until it is proven otherwise.

Answer 9

Your question assumes a false standard of rationality and a false epistemology.

You are assuming justificationism: the idea that it is possible and desirable to prove ideas true or probably true. For example, you talk about using induction, which supposedly makes ideas true or probably true by some process involving observation. In reality, you can't prove any position or show it is probable. Any argument requires premises and rules of inference and it doesn't prove (or make probable) those premises or rules of inference. If you're going to say they're self evident then you are acting in a dogmatic manner that will prevent you from spotting some mistakes. If you don't say they are self evident then you would have to prove those premises and rules of inference by another argument that would bring up a similar problem with respect to its premises and rules of inference.

In reality knowledge grows by processes that create variations on existing knowledge and then select among those variations. When a person creates knowledge he does this by guessing variations that might improve his ideas and then selecting among those variations according to whatever criteria he prefers. People thereby can and do guess about the properties of things they have never seen and can never see, such as the core of the sun, or whether other people are conscious.

The standard of rationality is not whether you have justified a belief but whether you would reject it if it was successfully criticised and whether you are interested in looking for criticism. It is not enough simply to state that there might conceivably be some unknown criticism or some unknown alternative solution of some problem. That would be true for absolutely any position you adopt and so that standard is worthless for criticising anything.

Why would you think other people are conscious? They talk about ideas and stuff and the only available account of why they do this is that they think. They talk about sensations and emotions and stuff like that and the only account we have of why they would do this is that they have sensations and emotions.

Answer 10

Since the time of Plato and the introduction philosophical principles of investigation. It is interesting to wonder if Zoomie philosophy and how do we know we're human have been debated. Geocentrism is a good point of reference, for do I have a mind or not? Am I a zoomie or not? Is this just flat earth speculation. David Bohm put forward the idea that Mind and physics are never ending possibilities on a work of physics and philosophy with Basil Hiley. His work on the ontology of quantum mechanics, on its interpretation as relating to the nature of reality, such as God, was opposed by the current and established Copenhegen interepration concerned only with measurement and probabilities (epistomology). It says that quantum mechanics in its present state is all that is, that there's nothing deeper than (delta_p.delta_x <= h_bar/2). On no scientific grounds at all but one of preference of philosophy.

Coming back to the main point "Obviously I'm not looking for a valid deductive proof using formal logic, but at least a relatively convincing argument. How do I know that humans who I encounter other than myself have sentient minds, and aren't just unfeeling zombies?"

Atheism and nothingness after death, seems to me, close to nothingness is nirvana in the eastern philosophies; Tao Te Ching another philosophical principle speaks of the Dao. Paradox. So how does this relate to how do I know I'm not a zoombie and that all other people have sentients minds? I am a zoombie, and I don't like it when other people persecute me by stigma!

Answer 11

Your senses will tell you that there are many people in the world who as far as your senses tell you, are not much different from yourself.

There's the possibility that what your senses tell you is all fake. You are just a computer simulation. In that case, others may not have sentient minds, but nor have you.

The other possibility is that what your senses tell you is right. There are many, you probably have direct evidence of thousands, who are not much different from yourself, as far as your senses are concerned. Your senses cannot detect sentient minds and thinking, but the others behave as if they had sentient minds like you (well, mostly). There is no good reason that they would be different from you in this important aspect.

Beyond that, ask yourself what happens if you act under the assumption that they have no sentient minds. Surely it isn't bad to "kill" a being without a sentient mind. Problem for you, there are all these non-sentient policemen who will catch you and throw you in a cell. Or if you insist they are non-sentient, they will put you in a straightjacket and you enter a different kind of cell that will be even harder for you to leave.

Answer 12

Recall that without assumptions there can be no conclusions. Hence, knowing that a belief in something requires assumptions, one can go all the way and assume this as an axiom.

However, what you were probably looking for was the minimal possible set of assumptions from which one could deduce this conclusion. In this case, you are faced with the problem of defining unambiguously exactly what consciousness is. In the absence of such a definition, your two possible conclusions above become equivalent.

Answer 13

Never, ever look at a matter with a theory already made or even half-made.

How do you then know what you are looking for? More precisely, how would you decide which properties of data to focus on? After all, you cannot focus at everything, by definition.

The answer is use a test. It will answer your question. Have a test thats fast enough and have a clear answer (don't have a mix answer).

Your energy should be used, at first and foremost on making that test.

Here is the test for your question: "Are they individually unique?" "Do they have enough individuality to tackle the same problem in different-than-other ways?".

Precisely, if they can make new tests to analyze their hypothesis and solutions, that is, to look at data, tests that they create, not copy, not simulate then they must be thinking on their own.

If on enough tests and enough complicated tests they all present same solution then they might be just acting on instinct, who knows?

A negative cannot be proved (unless you have full knowledge of system, which nobody can claim to have for over 8 billion humans). A positive can be. If your test find even one positive result (yes, they do have novel solutions) beyond test-errors then you have a conclusion. If hundreds of your tests show a negative result then you can reasonably conclude that your research showed a negative with open mind towards further data if and when it comes.

Answer 14

Argument:

1) First, lets assume you are not a brain in a jar, but part of life evolving on earth.

2) qualia (your sentience) evolved by evolution, since it provided some evolutionary advantage.

3) therefore, you are not the only human with qualia / sentience.

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That said, many people deny the existence of qualia, including notable philosophers and scientists.

Here is an incredible "Closer to Truth" interview with Marvin Minsky where he explains away qualia: https://www.youtube.com/watch?v=SNWVvZi3HX8

Dennett wrote "My view, put bluntly, is that there is no phenomenological manifold in any such relation to our reports", which prompted Chalmers to propose jokingly "Perhaps Dennett is a zombie" in his book The Conscious Mind.

But I think that when highly intelligent people, who spent their life thinking about these things deny qualia, we should take them by their word and acknowledge it is possible they do not have it.

Most of my friends, many of whom are software engineers, either deny the concept of qualia, or acknowledge it but insist that they do not see any reason why a hypothetical computer running the right piece of software shouldn't have what they term as qualia.

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So, there is a good argument for people having qualia, while it is conceivable that not all people have the same type of inner experience you do.

Answer 15

In my opinion, there is no way to prove conscience. There is no way to prove sentience. Are you sentient, or do you just think that? Do other people think that too? There is no test of sentience, as it is proven that artificial intelligence test designed by Turing are beatable. In truth, there can never be an answer. Are you alone a thinker? Are you a thinker in a sea of thinkers? Do you even think, or is a trick to feign you by your own instincts?