Monday, April 24, 2023

Schizophrenia and the problem of the external world

This morning I was thinking about that post I made a couple of days on schizophrenia and prophecy. There, I was talking specifically about how you might be able to tell whether some experience you had was a hallucination or not. It seems easier to rule visions, prophecies, etc. out than to rule them in. This morning, I was thinking about the problem more generally.

A person with schizophrenia might have all kinds of delusions and hallucinations. They're not limited to spiritual things. How might a person with schizophrenia tell whether they are seeing something that's really there or not? I'm not a psychiatrist or anything, but having read a lot about psychosis and schizophrenia, including testimonies from people who have it, I get the impression that for them, the hallucinations seem every bit as real as what the rest of us see on a daily basis. How do we know any of it is real? Maybe we all have schizophrenia, and none of this is real.

The problem of the external world comes from the fact that while it seems like we are more than reasonable in thinking that what our senses are telling us about what appears to be a world that exists outside of our minds is basically accurate, there's no way to prove it. It could all just be perception in our minds. I remember putting this problem to somebody one time, and him telling me, "Well, if I see a goat, and you tell me you see it, too, then I know there's a goat out there." But how does he know I'm out there? He's assuming the very thing that's under dispute. He only knows I'm out there telling him about the goat because he already trusts his sensory perception of me.

I've wrestled with that problem a lot and have come down on the side of weak foundationalism. There are just some items of knowledge that are built in. We don't infer them from anything else. They are a priori. We should assume things are basically like they appear to be unless we have really good reason to think otherwise. I've written about this in a few places.

Working Out an Epistemology
Knowledge By Sensory Perception
It's always more reasonable to affirm the obvious than to deny the obvious.

This epistemology doesn't depend on our sensory perceptions be infallible. Even the most mentally healthy among us see mirages and illusions from time to time, and we have dreams that at least seem real while we're having them. Our senses can and do deceive us. My epistemology only depends on our senses being generally reliable.

But it would seem my epistemology could be problematic for somebody with schizophrenia. If they saw an elephant floating in the air in front of them all of a sudden, that elephant may seem every bit as real as the tree just off to the left that's really there. If they apply my thumb rule, they will assume the elephant is real until they have good reason to think otherwise.

If somebody with schizophrenia sees something strange, and the person next to them doesn't see it, that might provide them with good reason to think it's not really there. But then how can they be sure the person next to them is really there? Does this undermine my whole epistemology, or do we just have to make an exception in the case of people with schizophrenia? Can people with schizophrenia have a justified belief in what their senses are telling them? Does epistemology work differently for them?

This seems even more problematic when it comes to the subject of visions. According to the Bible, some people really do see visions that are inspired by God. It is likely that had anybody been with Daniel or Ezekiel when they had their visions, nobody else would've seen what they saw. Should they have concluded it was a hallucination if the person with them couldn't verify it? Or should they continue to affirm what seems obvious to them until an even better reason comes along that disconfirms it, like I talked about in my last post? If they are justified in believing the visions even if nobody else saw them, then are people with schizophrenia justified in believing their hallucinations until something comes along to disconfirm it?

I'm enclined to think a person with schizophrenia who doesn't know they have schizophrenia is justified in believing their hallucinations. It is possible to be justified in believing something that is false. But it also seems to me there are lots of ways a person with schizophrenia can discover that what they are seeing isn't real.

Plantinga has this thought experiment in which you see what appears to be a dog in a field, so you conclude it's a dog. But then you find out there's a pill that can make you think you're seeing a dog every time you look at a sheep. Moreover, you know you just took that pill, and your host just told you there's a sheep in the field. That would destroy any warrant for trusting your senses about what appears to be a dog. Well, finding out you have schizophrenia could be just like that scenario. You've discovered that your belief-producing cognitive faulties aren't working right, so you have reason to doubt them. But without that information, it seems to me you would've been justified in believing it was a dog you were seeing. In the same way, I think a person suffering from psychosis can be justified in believing what they are seeing if they don't know they have psychosis.

There are lots of good reasons a person with psychosis might have to doubt what they are seeing. They might doubt it because (1) the person with them doesn't see it, (2) it's very strange or unusual, or (3) they know they have psychosis. Unless I have psychosis and just don't know it yet, I don't know what it's like. While some of them say their hallucinations seem just as real as everything else, it makes me wonder how they can ever be sure of anything. But presumably they are. A lot of them are functioning okay by using their sensory perceptions. They're just seeing a lot of extra stuff. Some of them learn to distinguish between the real and the hallucination. It would be interesting to meet a weak foundationalist who knew they had schizophrenia to see what they would say about all these things.

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