I think that others, including both humans and non-human animals, have mental states. I think certain things about their mental states, for example, that some, but not all, people perceive colors. But do I have any reason to believe any of this? My knowledge of others’ mental states seem to be private. That is, I cannot have any direct access to others’ mental states. I can only have direct access to my own mental states. So how can I justify my beliefs about others’ mental states, including my belief that others have mental states? If I cannot justify my beliefs about others’ mental states, then it’s not clear how I can know anything about others’ mental states. This is a problem, what I refer to as the problem of knowing other’s mental states.
If I cannot know anything about others’ mental states, then I cannot know if I’m giving pleasure or causing pain to others. If that’s the case, it’s not clear that I would be doing something immoral if I treat you like an object, something I can manipulate for my own pleasure. It’s not clear why I should spend any time worrying about the mental well-being of others, since I cannot know if anyone else suffers. In a later post, we will examine more closely the relationship between mental states and value.
Underlying this problem of knowing about other’s mental states is the idea that I can conceive of others behaving as I do in similar situations but these same others having different mental states than I have or no mental states at all. Consider the following case. I am outside in a park with my friend and we are both looking at some patch of grass. My friend and I, who both use color terms the same way, agree that the grass is green. Isn’t it conceivable that when my friend looks at the grass and says it looks green, the way the color of the grass looks to him is the way red things look to me? Isn’t it conceivable that the color of the grass doesn’t look any way at all to my friend? Couldn’t he be like a machine that can identify colors, but doesn’t have any conscious perception of them? As you think about these questions (assuming you can think), keep in mind that the scenario asserts that my behavior and my friend’s behavior are the same. So it’s not that my friend is colorblind and says that he is seeing no colors or a different color. Rather, he claims to be perceiving the colors the same way that I’m perceiving them. Since I seem to be able to conceive of these things, the skeptic argues I need to be able to show that they are not actually the case in order to know anything about the perception of my friend. But how can I show this, given that I cannot directly access his mental states?
According to the skeptic, it’s not only the perception of colors in others that I cannot know anything about. The skeptic argues that I can’t know anything about the mental states of others. Here is how the skeptic argues for this radical claim:
- It’s conceivable that others behave as I do in similar circumstances but have different kinds of mental states or have no mental states at all.
- The only way I can know anything about the mental states of others is by making an inference – i.e. drawing a conclusion – based on how others look – their physical makeup – and how they behave in certain circumstances.
- But there is no way for me to know whether such an inference is any good.
- Therefore I cannot know anything about the mental states of others, even if they have any.
Before we examine some responses to this skeptical argument, I want to emphasize that the skeptic is not claiming that others do not have mental states. Nor is the skeptic claiming that others mental states are in no way to similar to or different from my mental states. What the skeptic is claiming is that I cannot know anything about the mental states of others. So if others do have mental states or their mental states are similar to or different from mine, then, according to the skeptic, I cannot know this. Since I think the skeptic is mistaken, I need to respond to his argument.
Let’s start with premise 1. Is it conceivable that others behave as I do in similar circumstances but have different kinds of mental states or have no mental states at all? I’m not sure. My initial thought about this question is that it seems to depend on how the case is described. For example, if someone tells me about some person who slams a door on his finger and screams loudly, I do think I can conceive of this person behaving as if it’s painful, but really not feeling anything at all or experiencing some other sensation that is not painful. However, if I actually observe this person slam a door on his finger and scream loudly, it’s difficult for me to believe that the person is not feeling something that I would consider horribly painful if it happened to me. But perhaps I’m fooling myself when I think I can conceive anything about the mental states of others. As some philosophers have argued, the idea that others have mental states may not even make sense. Some philosophers claims that when I conceive of a pain as hurting that I necessarily conceive of it as hurting me. Similarly, when I conceive of what color grass looks like it seems that I necessarily conceive of what color it looks like to me. So, if these philosophers are correct, it’s not clear that I can conceive of how the color of grass looks to anyone else or how sensations feel to anyone else. It’s like conceiving something that is both a square and a circle, something that is contradictory. If I really cannot conceive of others experiencing anything, then I cannot know anything about their experiences. This means that the skeptic’s argument above is no good because premise 1 is false. But it also means that the argument is not even necessary to show that I cannot know anything about others’ mental states, at least those mental states that seem or feel a certain way. The idea of others having such mental states is just an inconceivable idea.
What about premise 2? Why should I believe that the only way I can know anything about the mental states of others is by making some sort of inference based on how others look and behave in certain circumstances? Answer: The knowledge of mental states is private. This means that I can only directly access my own mental states. I cannot directly access the mental states of others. Since I cannot have direct access to anyone else’s mental states, I need to appeal to some sort of evidence to justify my belief about others’ mental states. It seems that the evidence at my disposal is how people look – their physical makeup – and how behave in certain circumstances, including what they say. When I use such evidence I’m drawing a conclusion from what I can directly access to something that I cannot directly access.
Some philosophers have argued that the knowledge of mental states is not private and that one can have direct access to others’ mental states. If this is correct, then the skeptic’s argument is no good because premise 2 is false. It also means that I can know about the mental states of others. According to these philosophers, the reason I can directly access other’s mental states is that they are actually dispositions (or ‘tendencies’) to behave in certain ways under certain circumstances. This view in philosophy of mind is called behaviorism. Let’s illustrate this view with three examples of mental states, being in pain, believing that it’s going to rain, and being happy to see your friend. According to the behaviorist, to be in pain is to be disposed to do certain things (such as rub the injured body part or say that you’re in pain) when certain things happen to you (such as slamming a door on your finger). To believe that it’s going to rain is to do certain things (such as carry an umbrella or say it’s going to rain) when certain things happen to you (such as seeing dark clouds). To be happy about seeing your friend is to do certain things (such as smile or say you’re happy) when certain things happen to you (such as seeing your friend).
One reason for believing that behaviorism is true is that it explains the strong connection that seems to exist between mental states and dispositions to behave in certain ways characteristic of those mental state. This strong connection has to do with evidence. The presence of the characteristic behavioral dispositions of some mental state is evidence that an individual has the mental state. For example, if I see someone slam a door on his finger and then exhibit the characteristic behavioral dispositions of pain, such as screaming, I think I have good reason to believe that the person is in pain. Moreover, the failure to exhibit the characteristic behavioral dispositions of some mental state is evidence that the individual lacks that mental state. For example, if I see someone slam a door on his finger but didn’t exhibit any characteristic pain behavior, I think I have good reason to believe that the person is not in pain. The behaviorist thinks his theory of mental states – that they are dispositions to behave certain ways in certain circumstances – best explains this strong evidentiary connection. If to be in pain is just to be disposed to do certain things that are characteristic of pain behavior, then it makes sense why a person who is in pain does what he does and why a person who doesn’t exhibit pain behavior is not in pain.
There are few, if any, philosophers today who accept behaviorism. This is because there have been some strong arguments against the view. Perhaps the strongest objection is that when I introspect my own mental states it seems obvious that there is something it’s like for me to undergo them. It seems obvious to me that when I feel a pain, for example, there is something going on inside of me which constitutes my pain. The behaviorist denies that there is anything going on inside me; so it seems that the behaviorist must be mistaken. Another famous argument against behaviorism is that it seems that there are strong conceptual counter-examples to the view. According to behaviorism, it’s contradictory for a person to have the dispositions to behave in certain ways characteristic of a certain mental state without having that mental state. But it seems that I can conceive of someone who is a super-pretender – that is, someone who exhibits the characteristic behavioral dispositions of some mental state without having that mental state. According to behaviorism, it’s contradictory for a person to have a mental state without having the dispositions to behave in certain ways that are characteristic of that mental state. But it seems that I can conceive someone who is a super-spartan – that is, someone who has a mental state, but does not have any of the characteristic behavioral dispositions of that mental state. If I can conceive of either of these things, then behaviorism is a false theory of what mental states are.
Let’s finally move on to premise 3, the idea that there is no way for me to draw a conclusion about someone else’s mental states on the basis of how they look and behave. Let us recall that the skeptic believes is because he claims I cannot directly access anyone else’s mental states. But perhaps, as some philosophers have argued, I don’t need to directly access someone else’s mental states to be able to make a successful inference someone else’s mental states.
One strategy is to appeal to a commonly used type of argument known as an argument from analogy. An argument from analogy involves showing that some conclusion is true on the basis that two or more things are similar [watch this short video on arguments from analogy]. So, for example, I might conclude that the new movie directed by Christopher Nolan will be good, because I’ve seen other movies directed by Christopher Nolan and they were all good. Notice that in this argument by analogy the conclusion is talking about something I haven’t seen yet, namely the new movie directed by Christopher Nolan. Even though I haven’t seen it yet, I believe that it has an important relevant similarity to the Christopher Nolan movies that I’ve already seen, namely that it was directed by Christopher Nolan. Based on this similarity, I’m concluding that it will have another certain feature in common, namely being good.
Here’s how we can apply an argument from analogy to solve the problem of knowing other’s mental states. I know what’s going on in me when I put my hand on a hot stove by accident. I feel pain. I know how I behave when I feel this pain. I blurt out something like, “What an idiot!” and then rush to put some ice on my hand. I see someone else put their hand on a hot stove by accident. I see that they behave in a similar way as I do – they blurt out something and put ice on their hand. I then conclude on the basis of this similarity that this person must be feeling a painful sensation that feels like my pain, even though I cannot directly access this mental state. Therefore premise 3 is false, and I can know about the mental states of others. Does the argument from analogy move work?
There are many philosophers who think an argument by analogy won’t solve the problem of knowing other’s mental states. The problem is that doesn’t give much support to the conclusion because I don’t have a large enough sample size. When considering the strength of an argument by analogy one needs to consider how many things are being used as comparisons. If I’ve seen only one good movie directed by Christopher Nolan, then I have some reason to believe that the next one that he directs will be good. However, if I’ve seen many movies directed by Christopher Nolan and they were all good, then I have a much stronger reason to believe that the next one movie directed by him will be good. In the case of concluding anything about other’s mental states, I have only one case of mental states that I can directly access – mine – to use as a comparison. If I could know about others’ mental states the way in which I know my mental states (which I cannot), then I would have a larger sample size. So I do have some reason to believe that others have mental states like me. But it’s not much support.
The anti-skeptic has another type of argument in his arsenal. It’s called inference to the best explanation. This type of argument appeals to some observation and concludes a statement which best explains the observation. Often times, the statement that is being proved refers to something that cannot be observed. Example: I see Tom’s fingerprints on the murder weapon. I conclude that Tom must have been the murderer. Like the argument from analogy, inference to the best explanation is a commonly used argument in both science and everyday reasoning. Here’s how one can use it to show that others have mental states. I observe someone putting his hand on a stove and then pulling it off while screaming “Ouch!” and then rushing to put ice on it. I offer a possible cause for this behavior, namely that this person is experiencing a pain, which I cannot directly access. If this possible explanation is the best explanation for his behavior, then I have a reason to believe that he has a pain. Here’s another example. My friend is looking at some grass and says to me that it looks green. Since I have no reason to doubt him, I offer an explanation for why he says this. This explanation appeals to some mental state, namely the perception of green grass. If this is the best explanation for his behavior, then I have a reason to believe that he is having a perception.
An inference to the best explanation does not appeal to my mental states; so unlike an argument from analogy, its strength does not depend on a sample size. This is one of its advantages. However, the argument from analogy has an advantage that an inference to the best explanation seems to lack. When I give an argument from analogy I have some – albeit not a lot of – reason to believe that others have mental states like my mental states. I have some reason to believe that my friend’s perception of the color of the grass is like my perception of the color of the grass. It’s not clear that an inference to the best explanation will give me this information. In using an inference to the best explanation with my friend, I have reason to believe that he is having a perception. But do I have any reason to believe that his perception of the color green is like my perception of the color green? Why is this a better explanation than the explanation that his perception of the color is like my perception of the color red or some other color?
Perhaps we can use both the argument an argument from analogy and an inference to the best explanation to solve this last problem. What do you think?
