Jesse

Jesse:
Still seems like awkward phrasing. Perhaps it would be better to say that if an event is "inherently probabilistic", that means the outcome of any particular trial is not determined by anything (ie the outcome is uncaused), but over a large number of trials the ratios of different outcomes will tend to approach the ones in the probability distribution.

yguy:
That, at least, would be more honest in my view.

OK, so using this definition of "inherently probabilistic", would you still say that it's totally meaningless to say quantum events are inherently probabilistic, and therefore the statement is neither true nor false, or would you say the statement is just "absurd" or "impossible" and therefore false?

Jesse:
But you are able to conceive of statements about "causality" being more than merely epistemological claims? "Causality" has an epistemological side too--when we say event A causes event B, we're partly just saying whenever we see event A happening, we always predict B will happen. But I suspect you also think it's also meaningful to make the ontological claim that "A was really the cause of B". So what's the relevant difference?

yguy:
While both are epistemological claims, there is no implicit ignorance in those based on a claim of causality, without regard to whether such claims are veridical.

No implicit ignorance? I'm not so sure. Whenever we see that event B tends to follow A, we can't necessarily assume causality because "correlation is not causation", it's always possible we'll find some third event C which is the cause of both A and B. For instance, one might observe that people with red cars are more likely to have accidents than those with gray cars, but that doesn't mean we should tell people who already have red cars to paint them gray; it's more likely that there's some psychological factor which both increases the likelihood of preferring a red car and which increases the likelihood of getting into an accident.

Thus, whenever we decide that A is the cause of B, it's partly because we can't find any plausible third factor C that could be the cause of both A and B (for example, it's hard to think of a factor that would both predispose people to smoke and also predispose them to develop lung cancer). That sounds like a kind of implicit ignorance to me.

Jesse:
Why can't probability have an ontological side too?

yguy:
I suppose it does in the sense that probability theory can help describe reality to some useful degree. Like the theory of gravitation, however, it is a construct of the human mind rather than a law which the universe is constrained to obey.

And causation is not a construct of the human mind? When we say that A always causes B, is that a law which the universe is constrained to obey? Are you familiar with Hume's skepticism about causality? Hume's arguments set the stage for Kant's idea that things like space, causality, number, etc. are all "a priori" filters through which our minds view reality, but are not attributes of reality "in itself"...Kant might have made the same argument about causality that you make about probability, that it's purely an epistemological notion which becomes meaningless when applied to ontological claims about what reality is "really like".

Jesse:
But I don't see how there is any problem using "probability" in ontological statements about what the world is really like--if there is one, you certainly haven't been able to point it out.

yguy:
There isn't, as long as the ignorance (I'm not using the term pejoratively here) implicit in the idea is recognized.

Jesse:
Huh? Ignorance vs. knowledge are completely irrelevant to ontological claims, that's the domain of epistemology.

yguy:
There are no claims whatsoever which are outside the domain of epistemology.

There must be, if you think reality has properties independent of our beliefs about it. For us to know whether a particular ontological claim, such as "God exists", is actually true or not we must enter the domain of epistemology, but the claim itself may be solely an ontological one.

Similarly, "event X was uncaused" is an ontological claim; if you agree with my earlier definition of "inherently probabilistic" as "any particular outcome is uncaused, but in a large number of trials the ratio of frequency of different outcomes will approach the probability", then you're accepting that probability can have an ontological meaning as well as an epistemological one, even if you happen to believe it's false or even impossible that any real events could be inherently probabilistic in this sense.

Jesse

That's not quite true--all the weird quantum-mechanical behavior we have observed is still potentially compatible with a non-local hidden variables theory in which the apparent randomness is really the result of some pseudorandom deterministic process.

NialScorva

I was under the impression that you cannot solve for noncummuting observables and that this has been confirmed to the point that there is no doubt that it is accurate, at least to the extent that any further description must converge to this description for any situation that we know of now.

While there may be nonlocal hidden variables, does this invalidate the HUP? In other words, does the HUP depend upon the speed of light as a limitting factor (perhaps imported through Plank's constant)?

yguy

The latter.

You have corrupted your example with the injection of probability, making it no longer a purely causal claim such as electrical current causing the filament in a light bulb to glow.

Not that I'm aware, if you are talking about such things as the light bulb or projectiles fired from Earth tracing a parabolic arc. However, I see no justification for the idea that any effects can ultimately be traced to a point where there is no cause - which is what QM seems to imply - without adding God to the equation.

As for the Hume link, what I got out of it is the idea that we cannot continue cause and effect reasoning from one time segment to the next. What I see is not a refutation of the actuality of causality, but a refutation of the idea that intellectual reason can accurately determine the nature of any cause-effect relationship.

But all claims are based on something being known or thought to be known, so how can you divorce an ontological claim from epistemology?

Perhaps my statement would be more precise if I said "entirely outside the domain of epistemology."

I see nothing here to disagree with, since you affirm the epistemic aspect of the claim.

yguy

I am? About what?