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Is the universe deterministic?

  1. Jun 30, 2010 #1
    Are the causal relations that we see around us complete and going back to the birth of universe? Is there any real randomness? Is there anything else other than causal relations and randomness in order to be able to have free will?
    I know these are open question in philosophy and science. Please come with arguments.
  2. jcsd
  3. Jun 30, 2010 #2
    Yes, the universe is deterministic. I know it would be more helpful if I elaborated, but unfortunately that's out of my control.
  4. Jun 30, 2010 #3
    So, you say complete causality, no randomness, no free will...
  5. Jun 30, 2010 #4
    To even entertain the notion of determinism seems ludicrous to me. The ultimate reality is whatever humans perceive. All of our reasoning, all of our logic, is ultimately a product of this perception. To then use the faculty of reason to suggest a higher reality than perception seems pointlessly contrary. It's not testable, it's not tenable. What purpose would you have for denying the most self evident aspect of life?

    You might as well jump in front of a bus if you think you have no free will. I mean, it's not like you could stop yourself.
  6. Jun 30, 2010 #5
    Nobody can say this. QM could be random (most interpretations).

    Oh boy. If materialism: All I'll say is, if the brain follows physical law, then the brain follows physical law. No matter whether you want to find the explanatory variables by reducing or thinking in terms of strong emergence. Laws that govern higher order interactions are still laws. Randomness doesn't help the picture, as all it introduces are fully determined probability distributions of events. You need a third type of causality, one beyond anyone's wildest imagination. Even if you wish to propose that laws somehow break down in extremely complex systems, this doesn't give you free will. The antecedent of that breaking down is determinism/randomness which forms an unknown level of constraint on that 'breakage'.

    If someone proposes a coherent model of how such a causality could arise, they will be the most unprecedented genius ... ever. But it probably won't be done.

    But even though the brain follows the constraint of physics - random or otherwise - FAPP (for all practical purposes) to yourself, you have free will.

    I'm going to assume you're a materialist, if you're not the debate is moot because there isn't physical causal closure. I'm also going to assume you hold a definition of free will that people on the street think they have. So, do you wish to propose a mechanism outside of randomness and determinism? I'm all ears, really. But unfortunately we have no reason to suspect the brain doesn't follow laws, which means no free will under the definition I provided that I assumed you think is correct. Self-evidence is never a good argument. Ever.

    Even if consciousness is 'X' processes, and there are specific laws that arise at that level of interaction that can't be reduced, that is no argument whatsoever for the existence of free will. They are still laws. Brain is still constrained under those laws.
    Last edited: Jun 30, 2010
  7. Jun 30, 2010 #6


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    Our universe appears to be pretty damn deterministic. If causality is a coincidence of many superimposing random events, than that would be pretty miraculous in itself, especially with how often something like, say, gravity passes the existence test (100% in all my experiments... I have a record of scars outlining the detailed impact of each free-body fall).

    When it comes to organisms and free-will, you're talking about very complicated, difficult to predict, determinism (but determinism none the less): Nonlinear systems, chaos, extreme sensitivity to initial conditions and particular kinds of perturbations. This is why determinism has no affect on individuality (because each person, in addition to having a slightly different set of genes, experiences different aspects of the world).

    Of course, for organisms to persist in a stable manner through time (through reproduction) they have to all conform to certain laws, somehow. They have to be able to predict dangers and avoid death until they reproduce. Of course, this isn't the whole story. If a biological system is stressed to the point where it cannot function properly, it may just give up and die.

    This is why it's difficult (impossible, from a deterministic perspective) for your average, non-stressed organism, to willfully step in front of a bus that has a good chance of killing or maiming him (or her). Which is why you're suggestion is silly. It's very unlikely that anybody here will be able to step in front of it because of determinism's influence on freewill.
  8. Jun 30, 2010 #7
    But really, is any metaphysical view of time completely testable? Sure, some models can be ruled out. For example, the fact that physical laws depend on the time derivatives certain physical quantities means that presentism (i.e. the view that only the present exists) is probably not correct. But even quantum indeteminacy doesn't rule out the possibility that on a metaphysical level, the future exists now and has thus already been determined. We can certainly make epistemological claims about whether or not we can predict the future. And quantum indeterminacy would seem to suggest that we can't. I guess this would rule out Laplacian determinism. But I don't know if it would rule out all forms of determinism.
  9. Jul 1, 2010 #8
    Could you clarify your wording here. It seems you've snuck in "free will" without providing a reason to suspect it is there. It also seems you think determinism runs the brain but somehow the brain is not constrained by determinism.
  10. Jul 1, 2010 #9


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    Bad wording; I believe free will to be a human construct. I never implied the brain was not constrained by determinism: that is actually my point.
  11. Jul 1, 2010 #10
    Let me ask this directly: Given the same initial conditions you believe the same scenario will always play out identically? This is, I think, contrary to basic principles of QM, so you do not believe that element of it, or do you simply believe in a "guiding hand" beyond all of that?
  12. Jul 1, 2010 #11


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    A good question. And QM uncertainty would seem to say we can't even have "the same initial conditions" except as a thought experiment. There is an inherent graininess or vagueness in the real world (once you get down to small size/high energies).

    But say you could imagine a twin pair of wavefunctions, then your point here is that the collapse would be probabilistic. And my rejoinder to that is this is true only because QM does not model the collapse aspect - the boundary constraints that "determine" (well, constrain) the QM outcomes. Constraints can be weak in some cases (making the outcomes freer, or more unpredictable). Or stronger in others (making the outcomes quite predictable in practice).

    Furthermore, if we are bringing in the insights of "deterministic chaos", then we can turn things right around. A system released from any initial conditions will track towards its attractor. Does not matter how you start, you end up in the same general place. And this is indeed a constraints based view. It is the global that dominates the local (rather than the local adding up to create the global story).

    This is why the whole determined vs random, chance vs necessity, debate is so confused. It is not a case of either/or, but about the dynamic nature of an interaction.

    So if we want to talk about determinism in relation to complex systems, rather than the physically most simple, then a better intuition primer is to ask how a seed becomes a tree.

    Is the final outcome determined, or random, or a mix of both?

    Perhaps finally the fact that there is an interaction becomes obvious. A seed is a vague potential. Depending on where the seed falls, the nature of the soil and light, what grows up around it, the eventual tree can have all kinds shape. It can be tall, bent, twisted. Even in "identical conditions" no two trees will grow exactly the same as the tiniest deviations at the earliest stages of growth will be magnified in non-linear fashion.

    But equally, a tree always grows to look like a tree. There is enough information by way of boundary constraints (both in the seed's genes and the regularities of the environment - a sun overhead, etc) to determine the outcome.
  13. Jul 1, 2010 #12
    Nice way of working foliation in there! :) Yes, I see your point, but it can't be said that the fate of any given seed is to become a tree. The seed could fail, or a rogue insect or fungus could alter or end its growth. Even at this level of complexity, the outcomes may be limited (dead, alive, healthy, ill, shape of branches) to tree or not-tree, but is that deterministic in the way that has been discussed? Will any two or three BB events produce the same CMB? Uncertainty at a level well above the HUP can mean that the seed is ingested by a bird, pooped into river, where it eventually freezes for millenia. The fate of a seed is not deterministic, unless you're controlling the behavior of all other factors. It CAN only ever be a tree or a seed or a sapling, but it can have many fates that are unpredictable.
  14. Jul 1, 2010 #13


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    This is my point. Is the model we have of simple systems going to be the same we have of complex ones?

    The universe at the physical level can be best modelled in certain terms (where random and determined may make some kind of pragmatic sense). Then life and other forms of complexity may need to be measure across different dimensions (say spontaneity and autonomy).

    A really good model of things would be able to span both dimensions of description (simplexity and complicity). But continuing to focus solely on the language of one of these dimensions (is it all determined, is it all random?) is not the way to see this larger model.

    And yes, all sorts of fates can befall a seed. But you are betraying the standard prejudices in saying "The fate of a seed is not deterministic, unless you're controlling the behavior of all other factors."

    Constraint is not control (which would be strong determinism - by localised agents). Constraint is exactly what it says - a global limiting that restricts the space of the possible and so increases the chances of something locally actual. You could call it a weak determinism (though it can be pretty powerful). Or better yet, just give up on the notion of determinism as an ontological category.
  15. Jul 1, 2010 #14
    Free will may be no more complex than the ability to perceive multiple possibilities of action and to exercise conscious judgment in selecting one action over others. If rationality was 100% convergent, there might not be free will. If rationality could not be transcended in favor of irrational choices, there might also be no free will.

    I would guess if you could program a computer to recognize multiple choices and some algorhythm for logically weighing them against each other, and a random function that made it possible for the computer to apply multiple reasoning methods and methods for combining and overweighing conflicting results from those different methods, it would still need a random-choice generator to escape endless conflicts as to which choice was optimum.

    I don't think it would ever exercise the free-will to just go with its best guess at some point.
  16. Jul 1, 2010 #15


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    where do you get this from about QM? QM is deterministic!
  17. Jul 1, 2010 #16


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    There has been a lot of work to try to build artificial intelligence. And the best approaches are based on machines (neural nets) generating non-random states of prediction, then learning from these "choices".

    So it is a top-down, constraints-based, interactionist approach. You do make a best guess about what is about to happen next. Then the world may surprise you. And you then reshape your guessing so as to make a better guess next time.

    Freewill is then just about having a goal and an expectation about how the goal will be achieved. The goal becomes the constraint which shapes the best guess.
  18. Jul 1, 2010 #17
    Causal relations are apparent in our small part, and in our understanding, of the universe. The birth of the universe is another question entirely. Even seemingly random things can appear to contain patterns.

    I'd say determinism is a prejudice we have, which isn't to say its bad or not useful.
    Randomness certainly exists in terms of perspective, objective randomness might be a myth, or it might just be rare... but then there is no real pattern too randomness. So our universe may just be in a state of being randomly consistent.
    Consciousness... and the nature of consciousness is central, ie whether it is computational, emergent, or some magical soul-thing.
  19. Jul 2, 2010 #18
    You would need a new type of causality in order to have actual free will. I seriously doubt free will can exist under materialism. The illusion of it is no problem.

    What do you mean by "another question entirely."

    Bad definition, I think. I prefer the definition of the ability to act outside of the total constraint of physical law.
    Last edited: Jul 2, 2010
  20. Jul 2, 2010 #19

    Well put.

    I've been thinking about this soul-business for quite some time but it seems impossible to find the right framework(or even any framework at all) to try to make a case on it.

    Alfred Whitehead's views of 'blobs of perception' being fundamental do not address the seeming free will issue(they are consistent with relativity and probability though).
  21. Jul 2, 2010 #20


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    Randomness IS pattern. It is precisely the patterns that maximise entropy within a set of informational constraints.

    There really is no better recent paper on this than....

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