I know this has been discussed before, but I have read Sam Harris' book Free Will and Michael Shermer's book The Believing Brain, and I must say that I agree with both authors. Studies show that our brains make a decision on an unconscious level three tenths of a second and sometimes more before we even consciously know we're going to act. To take a short quote from Shermer's book: "The neural activity that precedes the intention to act is inaccessible to our conscious mind, so we experience a sense of free will. But it is an illusion, caused by the fact that we cannot identify the cause of the awareness of our intention to act".

Views: 4668

Reply to This

Replies to This Discussion

Indeed, it's always best if you can communicate with as little jargon as possible. Personally, I sometimes use jargon but tend to clarify such words in the process of discussion. Some very long concepts and ideas are packed into certain terms, however, and the process of unpacking those may or may not be worth it. It depends on both parties. I also suspect many who use them are unable to unpack them, and like you said, just  used to "mask the lack of argument". :)

Jonathan, I think you may have missed some of my earlier posts. In the second one I wrote:

My best guess is that neither determinism nor free will is the case. Many forces shape who we are, how we think, and what we do. Some are clearly beyond our control, others not. The important thing is conditioning—the narrowing of choices and the expansion of capacities through training and repetition.

You naturally assumed that in arguing against determinism, I was arguing in favor of free will. No, from my viewpoint it's a plague on both houses, not just one. However, while there is plenty of argument that free will is an illusion, there seemed to me little balancing argument that determinism is also an illusion. Consequently when the opportunity arose, I tried to provide some.

I expected you might agree with that. Early on you yourself allowed that the uncertainty principle undermines determinacy:

Quantum uncertainty does disprove determinism, but does it provide an example for free will?

Now you complain that I did not respond to your five points. Your first point was as follows:

1. QM does not invalidate classical physics on a macro level. Despite uncertainty, building codes are still well-founded by engineers, the projectile of a missile is still relatively predictable, and so are the properties of a particular species of trees.

No problem with that statement except relevancy. That the world appears  deterministic at the macro scale, that it is somewhat or approximately deterministic, does nothing to establish determinism as a philosophical principle. Underlying that apparent determinism of everyday events is the indeterminism at the micro level of quantum mechanies. If you try to measure precisely, you encounter exactly the limits of the uncertainty principle.

I know you are addressing Jonathan here, but it's good to see you understand that both determinism and indeterminism are a problem for free will.

That being said:

Underlying that apparent determinism of everyday events is the indeterminism at the micro level of quantum mechanics. 

..is an assumption of a specific Quantum interpretation (e.g. Copenhagen). It's important to note that.

Not in fact the case. I know you are thinking of the de Broglie-Bohm theory as deterministic, but it produces exactly the same uncertainty inequality as the standard theory and hence leads to exactly the same uncertainty in measurements.

Uncertainty in the sense of the Heisenberg uncertainty principle is intrinsic, which is what I have been trying to explain with all my regurgitated jargon. It does not vanish in the Bohm theory, in which a particle has in theory a well-determined trajectory—but one which can't be determined by any measurements we make.

It makes no practical difference whether you think the uncertainty is ontological or phenomenological, that is, whether you think it's in the nature of reality or in the nature of measuring it. The results are identical.

This is why the way you define "indeterminism" is incorrect, as Bohmian mechanics is, in physics, considered an entirely deterministic interpretation of QM. Again, determinism only means that such is entirely causal, not that we can measure such (certainty/uncertainty).

This seems to be a semantic problem  -which I'm saying how you are using such terms is incorrect. In Quantum Physics, there are numerous "deterministic" models, and they are considered "deterministic" due to them being "causal", not due to them being predictable or us being able to measure the momentum and position simultaneously.

Here is a short list of the more common interpretations and their status regarding "determinism" and "indeterminism":

Deterministic

  • de Broglie-Bohm theory
  • Many-worlds interpretation
  • Time-symmetric theories
  • Many-minds interpretation

Indeterministic

  • Copenhagen interpretation
  • von Neumann interpretation
  • Stochastic interpretation
  • Objective collapse theories
  • Transactional interpretation
  • Relational interpretation

Agnostic on being Deterministic

  • Ensemble interpretation
  • Quantum logic
  • Consistent histories

I'm partial to the ensemble interpretation myself, only because it makes the least assumptions. Regardless, it is incorrect to call all Quantum interpretations "indeterministic" models. Such is only reflected in the uncertainty principle for the Copenhagen variety of interpretations.

To put it another way, determinism doesn't mean "we can determine the trajectory of a particle", it ONLY means that the trajectory is determined by other events (causally). It's incorrect (though common) to conflate these two.

No problem with using deterministic = causal.  Just note that all the theories are uncertain in the sense that they include Heisenberg. It remains in any quantum theory based on waves (and as far as I know that is all of them). That is my point.

It seems you can define determinism in such a way that the uncertainty principle is part of a deterministic theory, but Heisenberg doesn't go away. What we observe does not change. You are merely saving appearances.

No experimental results are changed by these different interpretations and none of them thus far have been shown to improve upon the experimental results of classical quantum mechanics.

It does make for trouble in philosophy to have equivalent theories some deterministic and others not. It suggests that the concept of determinism is itself indeterminate, which I think is the point.

Personally I don't see much gained in being able to say that the universe is deterministic, but we can't determine the position and momentum of an electron at the same time. Does it give you that much comfort?

No problem with using deterministic = causal.  Just note that all the theories are uncertain in the sense that they include Heisenberg. It remains in any quantum theory based on waves (and as far as I know that is all of them). That is my point.

They are uncertain in the sense of what we can know, not what is (depending on the interpretation). My point is, for the free will debate, what applies is in regards to causal determinism...not uncertainty of knowledge.

Personally I don't see much gained in being able to say that the universe is deterministic, but we can't determine the position and momentum of an electron at the same time. Does it give you that much comfort?

Though a causally deterministic universe is more comforting than one in which acausal events pop into existence, I said before, I'm agnostic toward whether the universe is deteministic (entirely causal) or indeterministic (some acausal events). I don't take a side. What's more important is that neither help with free will.

Uncertainty of being able to know all of the variables has nothing at all to do with the topic of free will, nor the determinism or indeterminism that is incompatible with free will (which is the same as the determinism / indeterminism used in physics).

It does make for trouble in philosophy to have equivalent theories some deterministic and others not. It suggests that the concept of determinism is itself indeterminate, which I think is the point.

This doesn't follow. Again, the lack of knowledge of something doesn't imply indeterminacy. I'm trying to clean up your semantics on these terms because it's an important misunderstanding of how they are used in both philosophy and science.

You naturally assumed that in arguing against determinism, I was arguing in favor of free will.

Actually, I assumed that from the blog you posted earlier. The problem with rejecting determinism out of hand is you get positions like metaphysical libertarianism, which argues that because certain aspects of the world are indeterminate, the processes relating to free will must also be indeterminate. With the development of quantum mechanics, I doubt many would argue that the world is wholly deterministic, but the tendency to then assume the world is wholly indeterminate is even more grievous. We could argue that the world is adequately determinate, that there are certain types of events that are indeterminate, but for the most part, it is determinate.

I am not trying to establish determinism as a philosophical principle, I am trying to demonstrate how certain processes are determinate even if indeterminism is true. Even though indeterminism does no favors for free will, it is not even a necessary tool in the repertoire of a hard indeterminist or compatibilist.

1. There is significant predictability (or inference-ability) in the history of biological Evolution.

2. Quantum indeterminacy does not allow for predictability.

3. Therefore if Evolution is true, QI does not significantly influence Evolution (to the extent that it could not be described and experimented in the way that it is).

These kinds of syllogisms, with adequate determinism, are all that we require.

That an 'adequate' —that is to say, rough or approximate— determinism is sufficient for many purposes does not supply an adequate justification for rejecting an 'adequate' free will.

What form might that take? Libet, whose experiments of thirty years ago form the principal basis for much recent argument, has himself hypothesized in a 1999 paper on free will that there might be an unconstrained 'veto' power—or as one wag put it, "we may not have free will, but instead free won't."

Libet's delightful paper is available online:

http://www.centenary.edu/attachments/philosophy/aizawa/courses/intr...

He arrives at this point:

My conclusion about free will, one genuinely free in the non-determined sense, is then that its existence is at least as good, if not a better, scientific option than is its denial by determinist theory.

Define "adequate free will"? There are compatibilist definitions of free will that are fine, but they dismiss the philosophical import of the other free will semantics that tie into just about everything we think, say, and do. The one that allows us to blame others for not doing other than they did.

Nature Neuroscience is the updated version of the Libet experiments. But these experiments are only evidence against free will - not the full argument. The real dismissal of it is in it's logical incoherency.

The Libet conclusion is stretching, as all his experiment proved was that different stimuli arrive into fruition at different speeds. That one can appear to change his mind does not prove that the change is uncaused.

Three levels need to be considered: 1) the real world as it is; 2) physical observations of the real world; and 3) mathematical models and interpretations of the observations.

As you observe, the fact is there are several different models. Matrix mechanics, wave mechanics, and de Broglie-Bohm mechanics are mathematically equivalent. No experiment will be able to distinguish between them and select one over the others, although an experiment might eliminate them all.

The fact also is that one model is deterministic and the other two indeterministic. This suggests  the distinction between determinism and indeterminism does not lie in observations themselves, but in models of observations. In other words the determinism is not observable, or as Heisenberg would have it, cannot be justified as a physical reality, it is merely an interpretation.

RSS

line

Update Your Membership :

Membership

line

line

Nexus on Social Media:

line

© 2017   Atheist Nexus. All rights reserved. Admin: Richard Haynes.   Powered by

Badges  |  Report an Issue  |  Terms of Service