Michael

If you're a physicalist and believe that the mind is just brain processes (for example), do you understand idealism to be the claim that only brain pr...

Why? Do we require something to explain the separation of physical stuff? What separates this photon from that electron? Yes. Hempel's dilemma.

And the materialist has to show how mind A can know about body B via ideas in mind A. You might say that the ideas in mind A are caused by changes in ...

I see. Thanks.

I have "I believe p" as a premise. Does that not make a difference?

Are you even arguing for materialism here or dualism? Because if you're arguing for materialism then the mind is a physical thing, and so there should...

The premises are just "I believe ¬q" and "I believe p". Say "p" is "London is the capital city of England" and "q" is "pigs can fly".

Just an example of how the rules of entailment can lead to contradictory beliefs.

I think this is the problem: 1. I believe ¬q 2. ¬q ? ¬p ? ¬q 3. I believe ¬p ? ¬q 4. I believe p 5. p ? p ? q 6. I believe p ? q 7. p ? q ? ¬p ? q 8. ...

Those questions can be asked of the materialist as well. I don't understand why you think bodies being of substance A can avoid solipsism but bodies b...

You seem to be conflating. It isn't: ¬p ? Smith believes q Rather it's (allegedly): 1. Smith believes that ¬p ? q At the moment the truth of any propo...

I don't think it's really about that. I believe that if your name is John then your name is John or pigs can fly, but I don't believe that if your nam...

I think the issue is that whereas this is valid: 1. p 2. p ? q 3. ¬p ? q This probably isn't: 1. B(p) 2. B(p ? q) 3. B(¬p ? q) Perhaps relevance logic...

Yes. But my point is that premise 1 is "p", not "probably p and possibly not p".

Smith's belief that Jones owns a Ford is true if and only if Jones owns a Ford. So his belief is the unadorned "p".

If his belief is just "probably and possibly not " then his belief is true even if Jones doesn't own a Ford. Whereas if his belief is false if Jones d...

He's such an undignified President. He disrespects the office.

What I'm trying to get at is: ¬p ? q ? (¬p ? ¬q) The point is that if I'm asked what would follow if ¬p then I would withdraw the disjunction rather a...

This might actually be a better account of Smith's beliefs: Because Smith believes p and because p entails p ? q, Smith believes p ? (p ? q). p ? (p ?...

Sorry, meant "is true" not "is false".

Incidentally, the only mentions I can find of rejecting disjunction introduction are paraconsistent logics. There's also relevance logic that denies d...

Then what if we use this form: 1. One or both of "Jones owns a Ford" and "Brown is in Barcelona" is true If it helps, this proposition can be presente...

I think what you're bringing up is the paradox of material implication.

Here's an attempt: 1. p 2. p ? p ? q 3. p ? q 4. p ? q ? ¬p ? q 5. ¬p ? q 6. p ? ¬p ? q 6 is the principle of explosion, a valid rule of inference. Th...

I think the situation is this: 1. Smith believes that if "p" is true then "p ? q" is true 2. Smith believes that if "p" is false then "p ? q" might be...

One says that things are physical, the other that things are mental. It's a disagreement on the nature of the fundamental substance. It's not a disagr...

And the idealist can say the same.

Yes. So if I believe p1 and p2 then I will believe c1, and if I believe p1 and p3 then I will believe c2. What's the problem? But it's basic logic, so...

The formal implication of a disjunction is that if "p" is true then "p ? q" is true. Therefore the rational person who believes that "p" is true will ...

But let's continue with this example, as you seem to be OK with it. I am justified in believing that Donald Trump is the President. Therefore I am jus...

How is it any different? If I believe that Donald Trump is the President then I will believe that "Donald Trump is the President or Hillary Clinton is...

Materialism suffers from the same epistemological problem.

But this is what (some) idealists claim is the case. So you're saying that idealism can't avoid solipsism because non-solipsistic idealism is false? I...

And the idealist would agree. It's just that our body is a mental/immaterial thing, not a physical/material thing. If we go for Hume's bundle theory, ...

So you don't believe that "either Donald Trump is the President or Hillary Clinton is the President" is true? I believe that it's true, even though I ...

You're a mental thing and I'm a mental thing. When we "touch" this elicits in you certain experiences. It's the same sort of thing that happens for th...

So? You have some straw-man understanding of idealism. The idealist claim that all things are fundamentally mental or immaterial in nature is not to s...

And the idealist says the same. Only that the human beings that we interact with are mental/immaterial things, not physical/material things.

How does the materialist know that there are other minds? Yes. Isn't that also what the materialist says?

Sure, but we're talking about belief. If I believe that one of the kids in the phone booth is mine I don't necessarily believe that if it's not Bill t...

Are you forgetting about objective idealism, @"jorndoe"? To believe that all things are mental or immaterial is not to say that all things are my expe...

If I believe that the statement "Jones owns a Ford" is true and written in this book, and if I believe that "Brown is in Barcelona" is also written in...

I suppose that means that the term "or" suffers from the same sort of problem as the term "if ... then ..." (which unenlightened brought up earlier wi...

This doesn't seem like the correct interpretation of the disjunction at all. Let's say that there's a group of kids, and I believe that one of them is...

But again, you can apply Gettier's reasoning to this proposition: 1. One or both of "Jones owns a Ford" and "Brown is in Barcelona" is true A belief i...

Why? The propositions I'm comparing are ones that predicate truth, not falsehood. I'm not saying that these two are equivalent: 5. "London is the capi...

I don't understand your reasons. To say that "London is the capital city of England" is true is to say that London is the capital city of England and ...

So you're saying that the following two propositions are different? 1. "London is the capital city of England or pigs can fly" is true 2. One of both ...

Except "London is the capital city of England or pigs can fly" isn't nonsense. It's a meaningful English statement which is true if London is the capi...

I know that if I have evidence that you have a sibling then you cannot be an only child. That doesn't mean that I know that you're not an only child. ...