So a statement like "if I had opened the box at time t I would have found the cat to be dead" could be true even though the laws of nature do not determine that this would have been the outcome? — Michael

The laws of nature state that deterministically, that is only "half" the story. "Half" being used as shorthand for the proportion determined by the laws of physics.

A statement such as:

"if I had opened the box at earlier time t I would have found the cat to be dead"

Can't be given a truth value as it stands.

A statement such as:

"if I had opened the box at earlier time t, a proportion p of the instances of me would have found cat to be dead"

can.

By the way, we not only solve the ontological status of counterfactuals this way, but we solve the problems with the foundations of probability theory.

Honestly, you are only demanding to be given a "better law of nature" here - one that conforms to your bent for counterfactual definiteness at all times and places.

So for you, if QM's indeterminism is a falsification of your preference for metaphysical determinism, then you reject QM as an adequate account of nature. The world has to adjust itself so that it conforms to your notion of how to be truth-apt.

You started off backwards on this whole issue, and now you are aiming to be as backwards as it could possibly get.

So for you, if QM's indeterminism is a falsification of your preference for metaphysical determinism, then you reject QM as an adequate account of nature. The world has to adjust itself so that it conforms to your notion of how to be truth-apt. — apokrisis

Or you could just stick to Unitary Quantum Mechanics, and you can keep your determinism, solve the problem of counterfactuals, explain probability, discover the cause of the arrow of time...

Honestly, you are only demanding to be given a "better law of nature" here - one that conforms to your bent for counterfactual definiteness at all times and places.

So for you, if QM's indeterminism is a falsification of your preference for metaphysical determinism, then you reject QM as an adequate account of nature. The world has to adjust itself so that it conforms to your notion of how to be truth-apt.

You started off backwards on this whole issue, and now you are aiming to be as backwards as it could possibly get. — apokrisis

No, all I'm saying is that aletheist's solution to the problem of counterfactuals doesn't work. He said that "if X then Y" is true if the laws of nature determine that if X happens then Y will happen. But when it comes to quantum events, the laws of nature don't determine that if X happens then Y will happen; they only determine that if X happens then Y might happen – even if "if X then Y" is true.

So something other than the laws of nature make it the case that "if X then Y" is true.

A statement such as:

"if I had opened the box at earlier time t I would have found the cat to be dead"

Can't be given a truth value as it stands. — tom

This is ambiguous. Are you say that it doesn't have a truth value, or only that we can't determine what that truth value is? If the former then we've abandoned the principle of bivalence. If the latter then we need to refer to something other than the laws of nature to explain its truth value.

This is ambiguous. Are you say that it doesn't have a truth value, or only that we can't determine what that truth value is? If the former then we've abandoned the principle of bivalence. If the latter then we need to refer to something other than the laws of nature to explain its truth value. — Michael

Translating the statement slightly:

"In all the worlds where I opened the box at earlier time t, I discovered the cat to be dead"

Is a false statement.

This misses the whole point of the example. In context, Peirce was illustrating for his audience that laws of nature are real generals; it had absolutely nothing to do with his "power" to let go of the stone. If it helps, we can change the subjunctive conditional to eliminate that aspect: "If my hand were to disappear magically, then the stone would fall to the ground." — aletheist

It's not the power to drop the stone, which is relevant here, it's the power to hold the stone up in a position where it may be dropped, which is relevant. The proposed counterfactual is only produced according to this power to hold the stone above the floor. Set the stone on the table, and the table acts as that "power" which holds the stone above the floor.

This is the difference between the Newtonian way of looking at gravity, and the Einsteinian way. Newton looks at objects as separate from each other, such that their "natural state" is to be separate, and then a force, gravity is required to drive them together. The Einsteinian way reduces gravity to a property of the unity of objects, such that the natural state of objects is to be unified. But from this perspective it is necessary to determine the force which holds objects apart.

How can the laws of nature be "real generals" when something so simple as gravity can be understood in these two opposing ways? One way is that objects are naturally divided, and there is a force which moves objects toward each other, and the other way is that objects are naturally united, and there is a force which holds them apart.

No, what makes the first statement true is not some "power" that Peirce has. Rather, it is the fact that there is a real tendency in the universe for things with mass (such as a stone and the earth) to move toward each other in the absence of some intervening object (such as a man's body). — aletheist

So what is the "real counterfactual" here? Hasn't the man simply produced something unnatural, produced something counter-nature, by picking up the rock and separating it form the earth? Then your so-called "real tendency", is only the result of this artificial separation. Now the law, the so-called "real general", only applies in these instances of artificial separation. This real general doesn't apply to naturally occurring situations at all.

No, all I'm saying is that aletheist's solution to the problem of counterfactuals doesn't work. He said that "if X then Y" is true if the laws of nature determine that if X happens then Y will happen. But when it comes to quantum events, the laws of nature don't determine that if X happens then Y will happen; they only determine that if X happens then Y might happen – even if "if X then Y" is true. — Michael

You do realise that you keep trying to build in a classical notion of causality where the past constrains the future in some general fashion? So you are making what since QM - as in delayed choice quantum eraser experiments - has become a questionable presumption. Instead - retrocausally - the future can constrain the past.

So the laws of nature can be real generals, or actual constraints. But they are not as anchored in the general thermodynamic arrow of time or causality as classical metaphysics would presume. The quantum scale of action sits outside of this flow - doing its non-classical sum over all counterfactual possibilities so as to take even its unhappened future into account as part of its wavefunction.

Gravity is pulling on the stone in Peirce's hands. So that sets up a reasonable expectation in our minds. It would fall, but he is stopping that. However the stone has some remote possibility of quantum tunnelling through Peirce's mitts. That too is part of the natural law here. You just would treat it as a remote possibility as you are unlikely to think it reasonable to spend the rest of eternity waiting for that to happen.

So quantum natural law simply defies your preconceptions with regards to counterfactuality both in time and space. Counterfactually, the stone could be on the other side of Peirce's hands. Hence tunnelling really happens.

Translating the statement slightly:

"In all the worlds where I opened the box at earlier time t, I discovered the cat to be dead"

Is a false statement. — tom

That's not the statement I used. You're changing it to avoid addressing the problem. The statement is a counterfactual claim about the one world that I would have experienced, where only a single result is measured. I will never measure the coin to be both heads and tails and I will never measure the cat to be both dead and alive. It's one or the other, and it's a claim about what that one measurement would have been.

That's not the statement I used. You're changing it to avoid addressing the problem. — Michael

I'm solving your problem, or rather Modal Realism and Quantum Mechanics are independently solving your problem, and many other problems.

I'm solving your problem, or rather Modal Realism and Quantum Mechanics are independently solving your problem, and many other problems. — tom

You're not solving the problem. You haven't explained how the statement ""if I had opened the box at earlier time t I would have found the cat to be dead" can have a bivalent truth value.

All you're explaining is how different statements can have a bivalent truth value. But that's a red herring.

This is ambiguous. Are you say that it doesn't have a truth value, or only that we can't determine what that truth value is? If the former then we've abandoned the principle of bivalence. If the latter then we need to refer to something other than the laws of nature to explain its truth value. — Michael

Under unitary quantum mechanics, the statement, "if I had opened the box at earlier time t I would have found the cat to be dead" doesn't have a truth value because it doesn't unambiguously pick out a specific branch of the wave function.

In other words, the statement is not properly grounded.

You're not solving the problem. You haven't explained how the statement ""if I had opened the box at earlier time t I would have found the cat to be dead" can have a bivalent truth value.

All you're explaining is how different statements can have a bivalent truth value. But that's a red herring. — Michael

The clue is in the Modal Realism and the Quantum Mechanics.

If the statement agrees with the laws of physics, it is true - there is a world in which it is a fact. You might not be in that world, so for you the truth would be counterfactual.

If we are to accept imprecise statements as having a truth-value in the spirit of brevity and in full knowledge that we each are sufficiently versed in QM, so that we can assume each others meaning, then your statement is true, and has a single truth-value.

The clue is in the Modal Realism and the Quantum Mechanics.

If the statement agrees with the laws of physics, it is true - there is a world in which it is a fact. You might not be in that world, so for you the truth would be counterfactual.

If we are to accept imprecise statements as having a truth-value in the spirit of brevity and in full knowledge that we each are sufficiently versed in QM, so that we can assume each others meaning, then your statement is true, and has a single truth-value. — tom

The problem with this is that it entails that both "if I had opened the box at earlier time t I would have found the cat to be dead" and "if I had opened the box at earlier time t I would have found the cat to be alive" are true, as the cat being dead and the cat being alive are both possible outcomes of the measurement. So under your account we have to abandon the law of non-contradiction.

Under unitary quantum mechanics, the statement, "if I had opened the box at earlier time t I would have found the cat to be dead" doesn't have a truth value because it doesn't unambiguously pick out a specific branch of the wave function. — Andrew M

So I was right in saying that we have to abandon the principle of bivalence if we are to adopt this understanding of truth. And as the OP suggests, counterfactual claims (of a certain kind at least), can't be true.

No, we have to abandon the idea that the statement meaningfully refers to something. Suppose I was speaking to a crowd of people and I said, "You have a red shirt." That statement lacks a truth value unless I'm addressing a specific person.

The problem is not the principle of bivalence, it's the presence of ambiguity.

No, we have to abandon the idea that the statement meaningfully refers to something. Suppose I was speaking to a crowd of people and I said, "You have a red shirt." That statement lacks a truth value unless I'm addressing a specific person.

The problem is not the principle of bivalence, it's the presence of ambiguity. — Andrew M

So in other words all counterfactuals are trivially true (if physically possible) because we can simply stipulate that they refer to the possible worlds in which the described events happen?

So in other words all counterfactuals are trivially true (if physically possible) because we can simply stipulate that they refer to the possible worlds in which the described events happen? — Michael

Yes.

How can the laws of nature be "real generals" when something so simple as gravity can be understood in these two opposing ways? — Metaphysician Undercover

Because we construct different models of real generals, for different purposes.

Now the law, the so-called "real general", only applies in these instances of artificial separation. This real general doesn't apply to naturally occurring situations at all. — Metaphysician Undercover

"Artifical" vs. "natural" has nothing to do with it. If an earthquake were to dislodge a stone from the edge of a cliff, then it would fall to the bottom.

No, all I'm saying is that aletheist's solution to the problem of counterfactuals doesn't work. He said that "if X then Y" is true if the laws of nature determine that if X happens then Y will happen. — Michael

I said that "if X then Y" is true if the laws of nature are such that if X were to happen then Y would happen. I was not trying to offer a solution for any other type of counterfactual.

Suppose I was speaking to a crowd of people and I said, "You have a red shirt." That statement lacks a truth value unless I'm addressing a specific person. — Andrew M

Does it, though? What if ten people in the crowd had a red shirt? Does the statement fail to refer to them?

I've certainly listened to speakers use a general you to address some people in the crowd.

Maybe the problem is expecting that ordinary language propositions necessarily rely on bivalence. In the case of QM, the truth value can depend on which branch, if one adopts MWI.

Statements about counterfactuals might be normative: stating what one ought to believe. Or conventional: having to do with proper grammar.

The weatherman says it will probably rain today. Truth apt? Of course.

Does it, though? What if ten people in the crowd had a red shirt? Does the statement fail to refer to them?

I've certainly listened to speakers use a general you to address some people in the crowd.

Maybe the problem is expecting that ordinary language propositions necessarily rely on bivalence. In the case of QM, the truth value can depend on which branch, if one adopts MWI. — Marchesk

There's actually no problem making (bivalent) truth apt statements for quantum scenarios. The problem is only that statements that are truth apt in a classic scenario may not be truth apt in a quantum scenario because there is no one-to-one translation. The conceptual schemas are different and so just require different statements to be made.

The red-shirt statement does not refer if understood in its literal, singular sense in the crowd context. But, as you point out, it could be interpreted as referring to a subset of the crowd which could be expressed as, "some of you have red shirts". Alternatively, each person could interpret the singular statement as talking about them personally, in which case there would be multiple propositions with potentially different truth values.

This is really what is going on with the quantum counterfactual. Interpretations are being made that depend on the conceptual schema that the person holds. My view is that the wave function is real and that our conceptual schema should reflect this. On this view, there can be no fact about what would have happened to you (singular) if you had opened the Schrodinger's Cat box at an earlier time.

This conclusion is actually the basis of Bell's Theorem, where "fact" above is equivalent to "hidden variable" or "element of physical reality". Bell proved that the classical picture was incompatible with Einstein's principle of locality.

On this view, there can be no fact about what would have happened to you (singular) if you had opened the Schrodinger's Cat box at an earlier time. — Andrew M

That and the cat would know whether it was dead or alive. Never knew why a cat was different from a person in this scenario, as if there's something special about human observers that cat observers lack.

I know Schrodinger's point was that it was ridiculous to think the cat would be in a superposed state of alive and dead before we look, but a lot of people have taken it to mean the opposite.

know Schrodinger's point was that it was ridiculous to think the cat would be in a superposed state of alive and dead before we look, but a lot of people have taken it to mean the opposite. — Marchesk

Thermal decoherence adds extra constraints on those probabilities now, keeping the weirdness suitably quantum scale. The observer/collapse issue is not solved as such, but there is a commonsense work around where the statistics of the decaying particle (which causes the rather classical death by a shattered vial of poison) gives you a good argument for how soon the death is likely to happen.

I think there is a problem in that knowledge is about the past.

If I say "My mothers names is Anne" That could be false because my mother could have changed her name by deed poll to Susan. But It was true in the past that her name was Anne.

The laws of physics are a limited case because how many things refer to the laws of physics?
"If Germany won WW2" does not depend only on the laws of physics but on a huge range of occurrences including mental states and Historical contingencies.

If the laws of physics are certain or definite does that mean that they have been around and will be around for eternity? How many events are like this where the outcome was determined through eternity? That is to say how many laws are there with the same force.

And then there are contextual facts. Hitlers personality probably ensured that the Germans would never win WW2. If Hitler had a different psychology etc then he wouldn't be Hitler because the person we know as Hitler was defined by certain psychological traits and genetic inheritance.

So it could be "physically" impossible for the Germans to win WW2 and the only scenario in which they could have would be so radically different as to not to refer to the same things. Likewise if we said
"If Hitler had a better childhood"
Is it really possible for him to have had a different childhood without him being a different person altogether, because his parents circumstances and personalities etc would also have to be different. So I don't see that you can simply change one factor, but rather the whole causal chain would need altering.

What is it that is supposed to rest on counterfactuals?