Thursday, May 13, 2010

Where Rationalism Meets Empiricism

To review one aspect of the model being explored here:

The concrete world is a causal network of events; each event is an actualized outcome, selected from a set of possibilities*. Some form of modal realism is true: while the unactualized possibilities aren’t themselves concrete, they are real in some sense. Their reality is implicated in everything that happens.

I speculate that since we’ve evolved in this kind of world, we are naturally acquainted with possibilities. In fact, the consideration of possibilities is central to life (of animals, too) and to our reasoning. Somehow, humans leverage this acquaintance with possibilities to spin whole scenarios of how a world could be.

Contemporary rationalism takes the form of modal metaphysics – where one claims that our faculty for conceiving possible worlds is reliable. Like older forms of rationalism, it is vulnerable to critics who claim we can’t know about anything which is not experienced concretely.

But on this account, the space of possibilities is involved in every concrete event. These “abstract” entities are real and are implicated in causality. Therefore our modal reasoning (and by extension, our contemplation of all sorts of abstract concepts) is not disconnected from the empirical realm. Our rational faculties are grounded in our direct acquaintance with something real.

* An alternative account would characterize each event as a manifestation, resulting from an intersection of probabilistic dispositions, or propensities. In quantum physics, the analogues are the measurement event and the wavefunction.

10 comments:

Allen said...

What is evolution?

Is evolution possible in a deterministic universe?

Is evolution possible in an indeterministic universe?

Are there still "rules" in an indeterministic universe?

Is evolution a "rule" or is evolution an "emergent" consequence of other rules being followed?

Do you believe that your experiences are generated by some underlying process?

Is this underlying process "rule-governed"?

Steve said...

Hi Allen. I'll take a shot.

>>What is evolution?

Changing patterns in the network of events.

>>Is evolution possible in a deterministic universe?

I think not. I think real causality and asymmetric flow of time are incompatible with determinism.

>>Is evolution possible in an indeterministic universe?

Yes.

>>Are there still "rules" in an indeterministic universe?

Not deterministic rules, clearly, but possibilities are constrained by prior and adjacent events.

>>Is evolution a "rule" or is evolution an "emergent" consequence of other rules being followed?

I guess macro-level evolution would be considered emergent.

>>Do you believe that your experiences are generated by some underlying process?

Yes. As a macro-level entity, my experiences are formed by a complex pattern of events.

>>Is this underlying process "rule-governed"?

Not deterministic rules, but constraints, which do give rise to regularities.

Allen said...

>>What is evolution?

Changing patterns in the network of events.


Isn't this a rather trivial observation? That things change?

So in your post you say: "I speculate that since we’ve evolved in this kind of world, we are naturally acquainted with possibilities."

But given your definition of evolution...basically that "things change", what does your claim mean?

In a deterministic system, everything is a function of the initial conditions and the causal laws.

In an indeterministic system, everything is *still* a function of initial conditions and causal laws...it's just that the causal laws have a "probabilistic" aspect.

Where does evolution fit into this picture as an explanation of anything? Evolution isn't a causal law...it has no causal mechanism to act through, unlike electromagnetism or the other fundamental forces.

Evolution is just an after-the-fact description of how things have turned out. Any explanation has to be given in terms of fundamental physical laws acting on fundamental entities. Doesn't it?

So my translation of your sentence is:

"I speculate that since the initial conditions and causal laws of our world caused us to be naturally acquainted with possibilities, we are naturally acquainted with possibilities."

The original version sounded like you were saying something meaningful; but actually once you unpack all of the terms, it was just a tautology.

Or so it seems to me...

>>Are there still "rules" in an indeterministic universe?

Not deterministic rules, clearly, but possibilities are constrained by prior and adjacent events.


What is it that constrains the possibilities? Rules? But not deterministic rules - probabilistic rules?

Ultimately I think the split between deterministic and indeterministic rules is meaningless.

So if a physical law is deterministic then under it's influence Event A will "cause" Result X 100% of the time.

Why does Event A always lead to Result X? Because that's the law. There is no deeper reason.

If a physical law is indeterministic, then under it's influence Event B will "cause" Result Q, R, or S according to some probability distribution.

Let's say that the probability distribution is 1/3 for each outcome.

If Event B leads to Result R, why does it do so? Because that's the law. There is no deeper reason.

Event A causes Result X 100% of the time.

Event B causes Result R 33.3333% of the time.

Why? There is no reason. That's just the way it is.

Determinism could be seen as merely a special case of indeterminism...the case where all probabilities are set to 100%.

Right? So is there a real significant difference?


>>Is this underlying process "rule-governed"?

Not deterministic rules, but constraints, which do give rise to regularities.


What is the difference between a "rule" and a "constraint"?

Either your experiences are caused. Or they are uncaused. Either way, there's no free will, and no reason to believe that our experiences provide reliable information about the way things "really" are. Is there?

Steve said...

>>Evolution is just an after-the-fact description of how things have turned out. Any explanation has to be given in terms of fundamental physical laws acting on fundamental entities. Doesn't it?

You make a good point about the term “evolution”: I guess I don’t think it has special meaning other than to refer to complicated patterns of change.

>>Ultimately I think the split between deterministic and indeterministic rules is meaningless.

I disagree. The fact that some kind of indeterminism is true is an important point, since there are too many strict determinists out there. Possibilities are real, and that explains why they are central to life and mind.

>>Event A causes Result X 100% of the time.

>>Event B causes Result R 33.3333% of the time.

>>Why? There is no reason. That's just the way it is.

>>Determinism could be seen as merely a special case of indeterminism...the case where all probabilities are set to 100%.

>>Right? So is there a real significant difference?


To repeat: IMO this is a significant difference. But of course the reality gets more interesting.

First, it seems from QM that probabilities are capable of interaction effects prior to the measurement events, which creates even more complexity.

More importantly, the selection from the possible outcomes (which is the real causal step) is apparently not exactly how you describe. While it is the case in simple set-ups that outcomes in repeated trials will match predicted probabilities, there is a subjective aspect to quantum measurement which can’t be eradicated. The frequency interpretation of probability doesn’t work in QM. So, your description of initial conditions and objective probabilistic laws doesn’t describe the situation. (I can’t say I’m an expert on this stuff, obviously, but I reviewed this in some old posts for instance here and here).

Interestingly. particles can be interpreted to be freely choosing the outcome in a precisely symmetric way to the apparent freedom the researcher has in setting up the experiments. (see here and here). There’s a circular aspect to this, but the point stands that things are more interesting than either determinism or objective indeterminism.

>>Either your experiences are caused. Or they are uncaused. Either way, there's no free will, and no reason to believe that our experiences provide reliable information about the way things "really" are. Is there?

I think our introspection can certainly mislead us in significant ways, but I think some kind of freedom, grounded in quantum indeterminism, is very likely true. Causality itself incorporates an element of free selection among possibilities.

Allen said...

>> Causality itself incorporates an element of free selection among possibilities.

How does that work? I'd need to hear your definition of free selection to make any sense of that sentence. By what mechanism is this free selection incorporated? What rule governs free selection's application? How is free selection different than random selection?

I read your links, but I don't see that any of them apply to the point I was making, which isn't about probability per se, but causality. Not causality in the deterministic sense, but rather in the sense of:

"That which in any way gives existence to, or contributes towards the existence of, any thing; which produces a result; to which the origin of any thing is to be ascribed."

It seems to me that either our experiences are caused, or they are uncaused. There is no middle ground. In the later case, nothing more can be said about them...the experiences are fundamental.

But if our experiences are caused, then they are caused according to some rule, right? Though the rule may have some sort of probabilistic aspect. But, otherwise, what does "caused" mean? There has to be some "necessity" that connects the source event to the resulting effect. Doesn't there? Otherwise "cause" is an empty term.

If free selection emerges from some lower level of being, then by what rule does it emerge? What necessity causes it to emerge? If there is no governing rule, then it didn't emerge - it's appearance was uncaused. The existence and activity of the lower substrate was irrelevant.

Of course, if there are causal necessities, then what enforces them? What causes the causal necessities to hold? And what causes the causes of the causal necessities to hold? And so on, ad infinitum.

Steve said...

Here’s the idea. The fundamental, elementary unit of the concrete world is a causal event, which is a selection from possibilities. It is spontaneous and free, although it might be seen as random from a third person perspective. This selection, or actualization process, is the explanation for how causality works. Each event sets up and constrains the possibilities for the next, and a spontaneous selection is made. This is also the foundational unit for intentionality and experience.

There is no further explanation of this process. Allen: at some point explanation grounds out. If you think you can always keep asking for a mechanism ad infinitum, then you are arguing there just is no fundamental explanation (turtles all the way down).

As I’ve said before, our human experience is not caused by these elementary events, it is composed of them. We can debate the meaning of the word “emergence” I guess, to see if it applies here, but the idea is that our experience is a complex pattern of coordinated experiential events.

Allen said...

>> at some point explanation grounds out. If you think you can always keep asking for a mechanism ad infinitum, then you are arguing there just is no fundamental explanation (turtles all the way down).

So we have two possibilities.

1) There was a first cause. Since it was "first", then by definition, it was uncaused. Reality sprang into existence from nothing. There is no fundamental explanation for why things are the way they are.

2) There was no first cause. Instead, there exists an infinite chain of prior causes that culminates in the reality that we experience. But even if so, why this infinite causal chain instead of some other? Or instead of no chain at all? As you say, here too there is no fundamental explanation for why things are the way they are.

In either case, things just are the way they are. There is no explanation for why.

I think this is a significant point, though I don't think I've found anyone who agrees with me about it's significance.

The key thing is: if what underlies and generates our experiences can "just exist", then why not just say that our experiences themselves "just exist" without any underlying layers?


It is spontaneous and free, although it might be seen as random from a third person perspective.

Okay, from the third party perspective it looks random. Why isn't it *actually* random? What stops it from being random and instead makes it "free"?


Each event sets up and constrains the possibilities for the next, and a spontaneous selection is made.

So the "constraint" is a law-like necessity. Right? So, why this law instead of some other law? This law exists "objectively"? It's something real? Or is it just a description of how things seem to happen, and we refer to it as a "law" because we've never seen things happen otherwise?

As for "spontaneous selection", is there a rule for how this selection is done? If so, is it a human-comprehensible rule? Or do you think a rule exists, but it's nature is beyond human comprehension? If it is beyond human comprehension is that because we don't have access to the information needed to comprehend it, OR is it due to the limits of human intelligence and reasoning?

OR is "spontaneous select" effectively random?


the idea is that our experience is a complex pattern of coordinated experiential events.

So what is it that coordinates the experiential events? Is this something that "exists" and has causal power? Or is the fact that the experiential events are coordinated "just the way things are". The events *could* have been uncoordinated, but they're not. Why not? "There is no explanation for why not. This is just the way things are."

Ya?

Steve said...

>>In either case, things just are the way they are. There is no explanation for why.

Now we’re in the territory of the cosmological argument for the existence of God.

If explanations stop out somewhere, then there is some aspect of reality which “just exists” brutely. In my thinking about this it seemed to me that the space of all possibilities (a mega-, or pluriverse) probably does exist necessarily.

>>The key thing is: if what underlies and generates our experiences can "just exist", then why not just say that our experiences themselves "just exist" without any underlying layers?

The reason I think we can still have some specific explanations of the details of our local reality is that I respect the intuition that these things are contingent: they could have been different. So we ask why is the sky blue instead of green and we get some explanations.

As regards layers – ever since the first microscope, science seems to show very clearly that we are composite creatures. So I naturally think our experience is composite, too (if someone loses some neurons it makes a difference to there experience!). So we explain some things in terms of smaller things.

>>What stops it from being random and instead makes it "free"?

This is a surprisingly hard question. They have the same results – that’s why I think that it just depends on your perspective. If I’m choosing, it’s free; but if you look at the indeterminancy in my brain which gave rise to the choice, it looks random.

>>As for "spontaneous selection", is there a rule for how this selection is done?
>>OR is "spontaneous select" effectively random?

Asking for a rule sort of misses the point of “spontaneous” :)

>>So what is it that coordinates the experiential events?

I think that it’s self-organized, or participatory.

>>The events *could* have been uncoordinated, but they're not. Why not? "There is no explanation for why not. This is just the way things are.”

Science breaks things down and looks for patterns and regularities: to the extent these exist, they help explain our world, at least to a degree. We can try to explain human consciousness is a similar way, which will be aided by an acknowledgement that the smaller units of nature have an element of experience.

But when we keep pressing for more and more fundamental explanations, it gets harder. The regularities in some way probably arise due to some “shape” or tendency in the necessarily existing pluriverse. But, I think you’re right, that at that point we get as far as we can get.

mark said...

I would say to Allen too that one has to remember that these are concepts..."deterministic", "rule", etc. may exist in our minds, based upon what is perceived, but not the things themselves...I hear that the universe down the hall is cooler than ours, but different Planck's constant and all that, so we wouldn't be there.

mark said...

sorry: "...but are not the things themselves"