Whether it's unreasonable to doubt someone or something, depends on many factors given a particular context, but generally one needs to have good reasons to doubt. However, there can be causes for a doubt - for example, I may have poor eyesight.

Whether it's unreasonable to doubt someone or something, depends on many factors given a particular context, but generally one needs to have good reasons to doubt. However, there can be causes for a doubt - for example, I may have poor eyesight. — Sam26

So unless I have good reasons, I shouldn't doubt that you're an expert chess player, or that Banno is an expert tennis player? That doesn't seem right. Surely I need good reasons to believe that you are?

It seems to me that you're only saying that if we believe we have evidence that X is the case then we need good reasons to doubt it, whereas others are doubting whether or not we even have evidence that X is the case. I don't think the default position is that we do have evidence, and that additional reasons are required to doubt that we do.

If someone tells me that they're an expert, it can be reasonable to doubt them even if I don't have evidence that they're lying (or otherwise mistaken).

This is what I believe Magnus is talking about here. Whether or not to trust them is just a matter of choice.

So unless I have good reasons, I shouldn't doubt that you're an expert chess player, or that Banno is an expert tennis player? That doesn't seem right. Surely I need good reasons to believe that you are? — Michael

If I remember correctly, my example is that the teacher is an expert, and the information or evidence you have gives you reasons to believe he is an expert. So given such information, it would be unreasonable to doubt what he's telling you about the game of chess.

If someone tells me that they're an expert, it can be reasonable to doubt him even if I don't have evidence that he's lying (or otherwise mistaken). — Michael

You've changed the example, of course if someone simply tells me that he's an expert, that in itself doesn't mean that he is. Especially since there are so few experts in a field, so that in itself my make you question the person.

If I remember correctly, my example is that the teacher is an expert, and the information or evidence you have gives you reasons to believe he is an expert. — Sam26

So what evidence is this? What reasons do I have to trust this evidence over doubt it? As I said above, you only seem to be saying that if we believe that we have evidence that X is true then it is unreasonable to doubt that X is true, whereas others are questioning the antecedent.

I doubt that Y is evidence that the teacher is an expert. Do I need reasons? Do we simply assume that Y is evidence?

As I've said, the given is that he's an expert, thus it follows that his knowledge is superior to yours. In such a situation it would be unreasonable to doubt his knowledge, at least generally. You want me to spell out the evidence, but it isn't required for the example to work.

Now are there good reasons to sometimes doubt the experts, of course.

As I've said, the given is that he's an expert, thus it follows that his knowledge is superior to yours. — Sam26

I know that. But him being an expert isn't the same as me having evidence that he's an expert. Any random person who talks to me in the street might be an expert. Are you suggesting that in those occasions where, unknown to me, the person I'm talking to is an expert it would be unreasonable to doubt what he tells me? That doesn't strike me as right.

I need reasons to believe that the person I'm talking to is an expert. So given suggested evidence X (say, him telling me that he's an expert), am I to just assume that X is evidence that he's an expert? Or am I free to doubt that it's evidence, despite not having any evidence that he's lying?

But him being an expert isn't the same as me having evidence that he's an expert. Any random person who talks to me in the street might be an expert. — Michael

Agreed.

Are you suggesting that in those occasions where, unknown to me, the person I'm talking to is an expert it would be unreasonable to doubt what he tells me? That doesn't strike me as right. — Michael

Of course not, and I've already addressed this, at least I thought I did.

I need reasons to believe that the person I'm talking to is an expert. So given suggested evidence X (say, him telling me that he's an expert), am I to just assume that X is evidence? Or am I free to doubt that it's evidence, despite not having any evidence that he's lying? — Michael

Someone simply telling you they're an expert isn't good evidence that they are, so no, that wouldn't be enough. Here's the evidence you have: You saw him play in tournaments, you've read his expertise in articles and books, you know his rating according to FIDE is 2700, he owns a chess club where he teaches chess, etc., etc. Is that enough?

Someone simply telling you they're an expert isn't good evidence that they are, so no, that wouldn't be enough. Here's the evidence you have: First, you saw him play in tournaments, you've read his expertise in articles and books, you know his rating according to FIDE is 2700, he owns a chess club where he teaches chess, etc., etc. Is that enough? — Sam26

So how do we determine what is or isn't evidence? How do we determine when it is or isn't reasonable to doubt that something is evidence?

Using the above reasons, what evidence do I have that his score is 2,700? Am I to just assume that the source is accurate? Or am I free to doubt it until evidence that it's trustworthy is given to me? And then why should I believe that the evidence that it's trustworthy is itself trustworthy?

At some point, as Magnus has suggested, it just comes down to choice. You either trust that something is evidence or you doubt it. I don't think it right to say that doubt always requires evidence against, as if trust is the rational default.

So how do we determine what is or isn't evidence? — Michael

Wow, that's going to take a while to answer. You tell me. :D

Well, as has been suggested before, it mostly comes down to an attitude. Your attitude is either that of trust or doubt. I might not have any reasons to believe that someone is lying to me, but I still doubt that his words are evidence. And that's perfectly rational (or maybe it's pre-rational?).

Using the above reasons, what evidence do I have that is score is 2,700? Am I to just assume that the source is accurate? Or am I free to doubt it until evidence that it's trustworthy is given to me? And then why should I believe that the evidence that it's trustworthy is itself trustworthy? — Michael

Yes, if I was reading an official print out of FIDE ratings, I would make an assumption that it's accurate. At some point doubting just comes to an end, that is, I decide that I have enough evidence to support the idea that the man is a chess expert.

You can always create a scenario where it might be reasonable to doubt something, there's no denying that, but at some point your doubting just doesn't make sense. Let's say I have an inductive argument that's only 80% probable, is it reasonable to doubt the conclusion? I would say no. Why? Because most of the evidence is in favor of the conclusion.

Well, as Banno suggested before, it mostly comes down to an attitude. Your attitude is either that of trust or doubt. I might not have any reasons to believe that someone is lying to me, but I still doubt that his words are evidence. And that's perfectly rational. — Michael

Most of what we believe comes through the testimony of others, are we to doubt most of it? I think not. It's not about attitude, otherwise any doubt would be reasonable depending on your attitude. That doesn't seem rational to me.

Most people don't lie, so is it reasonable to assume someone is lying? Maybe, if most of the people you've been in contact with are liars.

Yes, if I was reading an official print out of FIDE ratings, I would make an assumption that it's accurate. — Sam26

And what evidence do you have that it's official? Do I need reasons to doubt it, or do I need reasons to trust it? I shouldn't just believe it because it says "official" in the text, as anyone could write that.

You can always create a scenario where it might be reasonable to doubt something, there's no denying that, but at some point your doubting just doesn't make sense. Let's say I have an inductive argument that's only 80% probable, is it reasonable to doubt the conclusion? I would say no. Why? Because most of the evidence is in favor of the conclusion.

My point is that the default position isn't that something is true, or that something is evidence. I don't need reasons to doubt that you're being honest with me, as if I should just assume that you're trustworthy.

If I tell you that I have a brother named John, should you just accept that? Would it be unreasonable to doubt that I'm telling you the truth, even though you likely don't have reason to believe that I'm lying?

Most people don't lie, so is it reasonable to assume someone is lying? Maybe, if most of the people you've been in contact with are liars.

Doubting that someone is telling the truth isn't the same as assuming that they're lying.

It's not real because it is fabricated by aliens.

What does it mean for the taste to be fabricated by aliens? You're using the words, but they don't mean much to me.

>> If I remember correctly, my example is that the teacher is an expert, and the information or evidence you have gives you reasons to believe he is an expert. So given such information, it would be unreasonable to doubt what he's telling you about the game of chess.

In other words, if you decide not to question his expertise it makes no sense to question his expertise. Great stuff.

It means their will decides how lemons taste to you. It means there is a strong correlation between what they want you to experience and what you experience.

It means their will decides how lemons taste to you. It means there is a strong correlation between what they want you to experience and what you experience. — Magnus Anderson

So by the "real" taste you mean what we would taste were we to eat a lemon without foreign interference? That makes more sense.

That's right.

So is it reasonable to suppose that there are aliens interfering with our taste buds?


Bedlam is ful of such reasonable folk.

That there is a problem. Do his tastebuds work incorrectly? Or has he misunderstood the meaning of the words "lemon" or "bitter"?

These are reasonable questions. What would be unreasonable would be to explain his odd behaviour by searching the sky for flying saucers.

It is perhaps worth pointing out again that believing something is performing an evaluation. It is choosing this over that. Of course you could have made the opposite choice. The choice you make tells us about you.

Choose Flying Saucers or malevolent daemons if you wish.

So is it reasonable to suppose that there are aliens interfering with our taste buds? — Banno

You have this problem of not being able to respond to what I am saying with something that is in some way relevant.

My point is that there is nothing that is immune to doubt. That's my point. And in order to demonstrate this, I had to show that there is always a possibility that we are wrong no matter how certain of our beliefs we are. Beliefs such as "lemons are bitter" are not necessarily true. There is always a possibility that they are wrong. I gave you an example of how such a belief can turn out to be wrong. I am not saying that such a belief is necessarily wrong. I am not saying that "lemons are bitter" is wrong. I am simply saying that such a belief MIGHT be wrong.

You preoccupy yourself with REASONS for questioning our beliefs. There can be any set of reasons for why we choose to question our beliefs. In fact, there might be no reasons at all -- we might question our beliefs for no reason at all. None of that is relevant. You give me the impression that you feel that you are under attack for the manner in which you maintain your beliefs. Again, I am not giving any instructions on how others should live their lives. What I am doing is I am simply saying that any belief can turn out to be wrong and that questioning your beliefs can turn out to be useful in one important sense: it can help you discover weaknesses in your position which can then motivate you to change your position in such a way so that it becomes a stronger position.

I assumed you were working with the definition of 'Constitutive Rule' given earlier in the thread, according to which a Constitutive Rule is an ostensive definition of a word. But here you say that a constitutive rule is 'what a culture takes to be inherently given in perception'. Is it what is actually given in perception, or merely what some people 'take' to be given? — PossibleAaran

The ostensive definitions of words just are what people in general take to be given in perception. What do you mean by "actually given in perception"? How could this be different than what people in general consider to be given in perception?

Doubt has to hinge on something we know. — Caldwell

I really can't understand this claim. Suppose that a person is overcome with a severe illness causing delusion, and hallucinations, with the appearance of all sorts of phantasms, paranoia and suspicion of everyone and everything. This person would be completely unsure of what was real. Wouldn't this person doubt everything and know nothing?

Why do you think that doubt must hinge on something known? What about a baby just born? Isn't this baby lacking in knowledge, but full of doubt? Isn't the fundamental learning process of trial and error based in doubt? And doesn't trial and error precede knowing?

Why do you think doubt must hinge on something known?

immune — Magnus Anderson

Interesting locution. What is this immunity here?

2+2=4 is not immune to doubt? But doubt here could only mean that the doubter did not know what "2", "+", "=" or "4" meant...

So what is it they are doubting? Not that 2+2=4, because they do not understand what that means, and so could not doubt it.

Consider my answers a bit more charitably, because I am confident I am responding to your argument.